From dc1ddacc9cc6029cebba8055c14c27c71439785f Mon Sep 17 00:00:00 2001 From: moneroexamples Date: Mon, 18 Jun 2018 08:16:53 +0800 Subject: [PATCH] json_detailedtransaction version added --- CMakeLists.txt | 4 +- ext/json.hpp | 25795 +++++++++++++++++++++++++++-------------------- src/page.h | 198 +- src/tools.h | 1 + 4 files changed, 15012 insertions(+), 10986 deletions(-) diff --git a/CMakeLists.txt b/CMakeLists.txt index 32ed10f..993a40e 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -6,9 +6,7 @@ set(PROJECT_NAME project(${PROJECT_NAME}) -set(CMAKE_CXX_FLAGS - "${CMAKE_CXX_FLAGS} -std=c++14") - +set(CMAKE_CXX_STANDARD 14) if (WIN32) set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wa,-mbig-obj -O3") diff --git a/ext/json.hpp b/ext/json.hpp index 48d797d..2b387a8 100644 --- a/ext/json.hpp +++ b/ext/json.hpp @@ -1,11 +1,12 @@ /* __ _____ _____ _____ __| | __| | | | JSON for Modern C++ -| | |__ | | | | | | version 2.1.1 +| | |__ | | | | | | version 3.1.2 |_____|_____|_____|_|___| https://github.com/nlohmann/json Licensed under the MIT License . -Copyright (c) 2013-2017 Niels Lohmann . +SPDX-License-Identifier: MIT +Copyright (c) 2013-2018 Niels Lohmann . Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal @@ -29,39 +30,100 @@ SOFTWARE. #ifndef NLOHMANN_JSON_HPP #define NLOHMANN_JSON_HPP -#include // all_of, copy, fill, find, for_each, none_of, remove, reverse, transform -#include // array +#define NLOHMANN_JSON_VERSION_MAJOR 3 +#define NLOHMANN_JSON_VERSION_MINOR 1 +#define NLOHMANN_JSON_VERSION_PATCH 2 + +#include // all_of, find, for_each #include // assert #include // and, not, or -#include // lconv, localeconv -#include // isfinite, labs, ldexp, signbit #include // nullptr_t, ptrdiff_t, size_t -#include // int64_t, uint64_t -#include // abort, strtod, strtof, strtold, strtoul, strtoll, strtoull -#include // memcpy, strlen -#include // forward_list -#include // function, hash, less +#include // hash, less #include // initializer_list -#include // hex -#include // istream, ostream -#include // advance, begin, back_inserter, bidirectional_iterator_tag, distance, end, inserter, iterator, iterator_traits, next, random_access_iterator_tag, reverse_iterator -#include // numeric_limits -#include // locale -#include // map -#include // addressof, allocator, allocator_traits, unique_ptr +#include // istream, ostream +#include // iterator_traits, random_access_iterator_tag #include // accumulate -#include // stringstream -#include // getline, stoi, string, to_string -#include // add_pointer, conditional, decay, enable_if, false_type, integral_constant, is_arithmetic, is_base_of, is_const, is_constructible, is_convertible, is_default_constructible, is_enum, is_floating_point, is_integral, is_nothrow_move_assignable, is_nothrow_move_constructible, is_pointer, is_reference, is_same, is_scalar, is_signed, remove_const, remove_cv, remove_pointer, remove_reference, true_type, underlying_type -#include // declval, forward, make_pair, move, pair, swap +#include // string, stoi, to_string +#include // declval, forward, move, pair, swap + +// #include +#ifndef NLOHMANN_JSON_FWD_HPP +#define NLOHMANN_JSON_FWD_HPP + +#include // int64_t, uint64_t +#include // map +#include // allocator +#include // string #include // vector +/*! +@brief namespace for Niels Lohmann +@see https://github.com/nlohmann +@since version 1.0.0 +*/ +namespace nlohmann +{ +/*! +@brief default JSONSerializer template argument + +This serializer ignores the template arguments and uses ADL +([argument-dependent lookup](http://en.cppreference.com/w/cpp/language/adl)) +for serialization. +*/ +template +struct adl_serializer; + +template class ObjectType = + std::map, + template class ArrayType = std::vector, + class StringType = std::string, class BooleanType = bool, + class NumberIntegerType = std::int64_t, + class NumberUnsignedType = std::uint64_t, + class NumberFloatType = double, + template class AllocatorType = std::allocator, + template class JSONSerializer = + adl_serializer> +class basic_json; + +/*! +@brief JSON Pointer + +A JSON pointer defines a string syntax for identifying a specific value +within a JSON document. It can be used with functions `at` and +`operator[]`. Furthermore, JSON pointers are the base for JSON patches. + +@sa [RFC 6901](https://tools.ietf.org/html/rfc6901) + +@since version 2.0.0 +*/ +template +class json_pointer; + +/*! +@brief default JSON class + +This type is the default specialization of the @ref basic_json class which +uses the standard template types. + +@since version 1.0.0 +*/ +using json = basic_json<>; +} + +#endif + +// #include + + +// This file contains all internal macro definitions +// You MUST include macro_unscope.hpp at the end of json.hpp to undef all of them + // exclude unsupported compilers #if defined(__clang__) #if (__clang_major__ * 10000 + __clang_minor__ * 100 + __clang_patchlevel__) < 30400 #error "unsupported Clang version - see https://github.com/nlohmann/json#supported-compilers" #endif -#elif defined(__GNUC__) +#elif defined(__GNUC__) && !(defined(__ICC) || defined(__INTEL_COMPILER)) #if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40900 #error "unsupported GCC version - see https://github.com/nlohmann/json#supported-compilers" #endif @@ -89,7 +151,7 @@ SOFTWARE. #endif // allow to disable exceptions -#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && not defined(JSON_NOEXCEPTION) +#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && !defined(JSON_NOEXCEPTION) #define JSON_THROW(exception) throw exception #define JSON_TRY try #define JSON_CATCH(exception) catch(exception) @@ -99,6 +161,20 @@ SOFTWARE. #define JSON_CATCH(exception) if(false) #endif +// override exception macros +#if defined(JSON_THROW_USER) + #undef JSON_THROW + #define JSON_THROW JSON_THROW_USER +#endif +#if defined(JSON_TRY_USER) + #undef JSON_TRY + #define JSON_TRY JSON_TRY_USER +#endif +#if defined(JSON_CATCH_USER) + #undef JSON_CATCH + #define JSON_CATCH JSON_CATCH_USER +#endif + // manual branch prediction #if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) #define JSON_LIKELY(x) __builtin_expect(!!(x), 1) @@ -108,772 +184,755 @@ SOFTWARE. #define JSON_UNLIKELY(x) x #endif -/*! -@brief namespace for Niels Lohmann -@see https://github.com/nlohmann -@since version 1.0.0 -*/ -namespace nlohmann -{ +// C++ language standard detection +#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464 + #define JSON_HAS_CPP_17 + #define JSON_HAS_CPP_14 +#elif (defined(__cplusplus) && __cplusplus >= 201402L) || (defined(_HAS_CXX14) && _HAS_CXX14 == 1) + #define JSON_HAS_CPP_14 +#endif -/*! -@brief unnamed namespace with internal helper functions +// Ugly macros to avoid uglier copy-paste when specializing basic_json. They +// may be removed in the future once the class is split. -This namespace collects some functions that could not be defined inside the -@ref basic_json class. +#define NLOHMANN_BASIC_JSON_TPL_DECLARATION \ + template class ObjectType, \ + template class ArrayType, \ + class StringType, class BooleanType, class NumberIntegerType, \ + class NumberUnsignedType, class NumberFloatType, \ + template class AllocatorType, \ + template class JSONSerializer> -@since version 2.1.0 -*/ -namespace detail -{ -//////////////// -// exceptions // -//////////////// +#define NLOHMANN_BASIC_JSON_TPL \ + basic_json /*! -@brief general exception of the @ref basic_json class - -Extension of std::exception objects with a member @a id for exception ids. +@brief Helper to determine whether there's a key_type for T. -@note To have nothrow-copy-constructible exceptions, we internally use - std::runtime_error which can cope with arbitrary-length error messages. - Intermediate strings are built with static functions and then passed to - the actual constructor. +This helper is used to tell associative containers apart from other containers +such as sequence containers. For instance, `std::map` passes the test as it +contains a `mapped_type`, whereas `std::vector` fails the test. -@since version 3.0.0 +@sa http://stackoverflow.com/a/7728728/266378 +@since version 1.0.0, overworked in version 2.0.6 */ -class exception : public std::exception -{ - public: - /// returns the explanatory string - virtual const char* what() const noexcept override - { - return m.what(); +#define NLOHMANN_JSON_HAS_HELPER(type) \ + template struct has_##type { \ + private: \ + template \ + static int detect(U &&); \ + static void detect(...); \ + public: \ + static constexpr bool value = \ + std::is_integral()))>::value; \ } - /// the id of the exception - const int id; +// #include - protected: - exception(int id_, const char* what_arg) - : id(id_), m(what_arg) - {} - static std::string name(const std::string& ename, int id) - { - return "[json.exception." + ename + "." + std::to_string(id) + "] "; - } +#include // not +#include // size_t +#include // numeric_limits +#include // conditional, enable_if, false_type, integral_constant, is_constructible, is_integral, is_same, remove_cv, remove_reference, true_type +#include // declval - private: - /// an exception object as storage for error messages - std::runtime_error m; -}; +// #include + +// #include + +namespace nlohmann +{ /*! -@brief exception indicating a parse error +@brief detail namespace with internal helper functions -This excpetion is thrown by the library when a parse error occurs. Parse -errors can occur during the deserialization of JSON text as well as when -using JSON Patch. +This namespace collects functions that should not be exposed, +implementations of some @ref basic_json methods, and meta-programming helpers. -Member @a byte holds the byte index of the last read character in the input -file. +@since version 2.1.0 +*/ +namespace detail +{ +///////////// +// helpers // +///////////// -@note For an input with n bytes, 1 is the index of the first character - and n+1 is the index of the terminating null byte or the end of - file. This also holds true when reading a byte vector (CBOR or - MessagePack). +template struct is_basic_json : std::false_type {}; -Exceptions have ids 1xx. +NLOHMANN_BASIC_JSON_TPL_DECLARATION +struct is_basic_json : std::true_type {}; -name / id | example massage | description ------------------------------- | --------------- | ------------------------- -json.exception.parse_error.101 | parse error at 2: unexpected end of input; expected string literal | This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member @a byte indicates the error position. -json.exception.parse_error.102 | parse error at 14: missing or wrong low surrogate | JSON uses the `\uxxxx` format to describe Unicode characters. Code points above above 0xFFFF are split into two `\uxxxx` entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point. -json.exception.parse_error.103 | parse error: code points above 0x10FFFF are invalid | Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid. -json.exception.parse_error.104 | parse error: JSON patch must be an array of objects | [RFC 6902](https://tools.ietf.org/html/rfc6902) requires a JSON Patch document to be a JSON document that represents an array of objects. -json.exception.parse_error.105 | parse error: operation must have string member 'op' | An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors. -json.exception.parse_error.106 | parse error: array index '01' must not begin with '0' | An array index in a JSON Pointer ([RFC 6901](https://tools.ietf.org/html/rfc6901)) may be `0` or any number wihtout a leading `0`. -json.exception.parse_error.107 | parse error: JSON pointer must be empty or begin with '/' - was: 'foo' | A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a `/` character. -json.exception.parse_error.108 | parse error: escape character '~' must be followed with '0' or '1' | In a JSON Pointer, only `~0` and `~1` are valid escape sequences. -json.exception.parse_error.109 | parse error: array index 'one' is not a number | A JSON Pointer array index must be a number. -json.exception.parse_error.110 | parse error at 1: cannot read 2 bytes from vector | When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read. -json.exception.parse_error.111 | parse error: bad input stream | Parsing CBOR or MessagePack from an input stream where the [`badbit` or `failbit`](http://en.cppreference.com/w/cpp/io/ios_base/iostate) is set. -json.exception.parse_error.112 | parse error at 1: error reading CBOR; last byte: 0xf8 | Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read. -json.exception.parse_error.113 | parse error at 2: expected a CBOR string; last byte: 0x98 | While parsing a map key, a value that is not a string has been read. +// alias templates to reduce boilerplate +template +using enable_if_t = typename std::enable_if::type; -@since version 3.0.0 -*/ -class parse_error : public exception +template +using uncvref_t = typename std::remove_cv::type>::type; + +// implementation of C++14 index_sequence and affiliates +// source: https://stackoverflow.com/a/32223343 +template +struct index_sequence { - public: - /*! - @brief create a parse error exception - @param[in] id the id of the exception - @param[in] byte_ the byte index where the error occured (or 0 if - the position cannot be determined) - @param[in] what_arg the explanatory string - @return parse_error object - */ - static parse_error create(int id, size_t byte_, const std::string& what_arg) + using type = index_sequence; + using value_type = std::size_t; + static constexpr std::size_t size() noexcept { - std::string w = exception::name("parse_error", id) + "parse error" + - (byte_ != 0 ? (" at " + std::to_string(byte_)) : "") + - ": " + what_arg; - return parse_error(id, byte_, w.c_str()); + return sizeof...(Ints); } +}; - /*! - @brief byte index of the parse error +template +struct merge_and_renumber; - The byte index of the last read character in the input file. +template +struct merge_and_renumber, index_sequence> + : index_sequence < I1..., (sizeof...(I1) + I2)... > {}; - @note For an input with n bytes, 1 is the index of the first character - and n+1 is the index of the terminating null byte or the end of - file. This also holds true when reading a byte vector (CBOR or - MessagePack). - */ - const size_t byte; +template +struct make_index_sequence + : merge_and_renumber < typename make_index_sequence < N / 2 >::type, + typename make_index_sequence < N - N / 2 >::type > {}; - private: - parse_error(int id_, size_t byte_, const char* what_arg) - : exception(id_, what_arg), byte(byte_) - {} -}; +template<> struct make_index_sequence<0> : index_sequence<> {}; +template<> struct make_index_sequence<1> : index_sequence<0> {}; -/*! -@brief exception indicating errors with iterators +template +using index_sequence_for = make_index_sequence; -Exceptions have ids 2xx. +/* +Implementation of two C++17 constructs: conjunction, negation. This is needed +to avoid evaluating all the traits in a condition -name / id | example massage | description ------------------------------------ | --------------- | ------------------------- -json.exception.invalid_iterator.201 | iterators are not compatible | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. -json.exception.invalid_iterator.202 | iterator does not fit current value | In an erase or insert function, the passed iterator @a pos does not belong to the JSON value for which the function was called. It hence does not define a valid position for the deletion/insertion. -json.exception.invalid_iterator.203 | iterators do not fit current value | Either iterator passed to function @ref erase(IteratorType first, IteratorType last) does not belong to the JSON value from which values shall be erased. It hence does not define a valid range to delete values from. -json.exception.invalid_iterator.204 | iterators out of range | When an iterator range for a primitive type (number, boolean, or string) is passed to a constructor or an erase function, this range has to be exactly (@ref begin(), @ref end()), because this is the only way the single stored value is expressed. All other ranges are invalid. -json.exception.invalid_iterator.205 | iterator out of range | When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the @ref begin() iterator, because it is the only way to address the stored value. All other iterators are invalid. -json.exception.invalid_iterator.206 | cannot construct with iterators from null | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range. -json.exception.invalid_iterator.207 | cannot use key() for non-object iterators | The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key. -json.exception.invalid_iterator.208 | cannot use operator[] for object iterators | The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. -json.exception.invalid_iterator.209 | cannot use offsets with object iterators | The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. -json.exception.invalid_iterator.210 | iterators do not fit | The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. -json.exception.invalid_iterator.211 | passed iterators may not belong to container | The iterator range passed to the insert function must not be a subrange of the container to insert to. -json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container. -json.exception.invalid_iterator.213 | cannot compare order of object iterators | The order of object iterators cannot be compated, because JSON objects are unordered. -json.exception.invalid_iterator.214 | cannot get value | Cannot get value for iterator: Either the iterator belongs to a null value or it is an iterator to a primitive type (number, boolean, or string), but the iterator is different to @ref begin(). +For example: not std::is_same::value and has_value_type::value +will not compile when T = void (on MSVC at least). Whereas +conjunction>, has_value_type>::value will +stop evaluating if negation<...>::value == false -@since version 3.0.0 +Please note that those constructs must be used with caution, since symbols can +become very long quickly (which can slow down compilation and cause MSVC +internal compiler errors). Only use it when you have to (see example ahead). */ -class invalid_iterator : public exception -{ - public: - static invalid_iterator create(int id, const std::string& what_arg) - { - std::string w = exception::name("invalid_iterator", id) + what_arg; - return invalid_iterator(id, w.c_str()); - } - - private: - invalid_iterator(int id_, const char* what_arg) - : exception(id_, what_arg) - {} -}; +template struct conjunction : std::true_type {}; +template struct conjunction : B1 {}; +template +struct conjunction : std::conditional, B1>::type {}; -/*! -@brief exception indicating executing a member function with a wrong type +template struct negation : std::integral_constant {}; -Exceptions have ids 3xx. +// dispatch utility (taken from ranges-v3) +template struct priority_tag : priority_tag < N - 1 > {}; +template<> struct priority_tag<0> {}; -name / id | example massage | description ------------------------------ | --------------- | ------------------------- -json.exception.type_error.301 | cannot create object from initializer list | To create an object from an initializer list, the initializer list must consist only of a list of pairs whose first element is a string. When this constraint is violated, an array is created instead. -json.exception.type_error.302 | type must be object, but is array | During implicit or explicit value conversion, the JSON type must be compatible to the target type. For instance, a JSON string can only be converted into string types, but not into numbers or boolean types. -json.exception.type_error.303 | incompatible ReferenceType for get_ref, actual type is object | To retrieve a reference to a value stored in a @ref basic_json object with @ref get_ref, the type of the reference must match the value type. For instance, for a JSON array, the @a ReferenceType must be @ref array_t&. -json.exception.type_error.304 | cannot use at() with string | The @ref at() member functions can only be executed for certain JSON types. -json.exception.type_error.305 | cannot use operator[] with string | The @ref operator[] member functions can only be executed for certain JSON types. -json.exception.type_error.306 | cannot use value() with string | The @ref value() member functions can only be executed for certain JSON types. -json.exception.type_error.307 | cannot use erase() with string | The @ref erase() member functions can only be executed for certain JSON types. -json.exception.type_error.308 | cannot use push_back() with string | The @ref push_back() and @ref operator+= member functions can only be executed for certain JSON types. -json.exception.type_error.309 | cannot use insert() with | The @ref insert() member functions can only be executed for certain JSON types. -json.exception.type_error.310 | cannot use swap() with number | The @ref swap() member functions can only be executed for certain JSON types. -json.exception.type_error.311 | cannot use emplace_back() with string | The @ref emplace_back() member function can only be executed for certain JSON types. -json.exception.type_error.313 | invalid value to unflatten | The @ref unflatten function converts an object whose keys are JSON Pointers back into an arbitrary nested JSON value. The JSON Pointers must not overlap, because then the resulting value would not be well defined. -json.exception.type_error.314 | only objects can be unflattened | The @ref unflatten function only works for an object whose keys are JSON Pointers. -json.exception.type_error.315 | values in object must be primitive | The @ref unflatten function only works for an object whose keys are JSON Pointers and whose values are primitive. +//////////////////////// +// has_/is_ functions // +//////////////////////// -@since version 3.0.0 -*/ -class type_error : public exception -{ - public: - static type_error create(int id, const std::string& what_arg) - { - std::string w = exception::name("type_error", id) + what_arg; - return type_error(id, w.c_str()); - } +// source: https://stackoverflow.com/a/37193089/4116453 - private: - type_error(int id_, const char* what_arg) - : exception(id_, what_arg) - {} -}; +template +struct is_complete_type : std::false_type {}; -/*! -@brief exception indicating access out of the defined range +template +struct is_complete_type : std::true_type {}; -Exceptions have ids 4xx. +NLOHMANN_JSON_HAS_HELPER(mapped_type); +NLOHMANN_JSON_HAS_HELPER(key_type); +NLOHMANN_JSON_HAS_HELPER(value_type); +NLOHMANN_JSON_HAS_HELPER(iterator); -name / id | example massage | description -------------------------------- | --------------- | ------------------------- -json.exception.out_of_range.401 | array index 3 is out of range | The provided array index @a i is larger than @a size-1. -json.exception.out_of_range.402 | array index '-' (3) is out of range | The special array index `-` in a JSON Pointer never describes a valid element of the array, but the index past the end. That is, it can only be used to add elements at this position, but not to read it. -json.exception.out_of_range.403 | key 'foo' not found | The provided key was not found in the JSON object. -json.exception.out_of_range.404 | unresolved reference token 'foo' | A reference token in a JSON Pointer could not be resolved. -json.exception.out_of_range.405 | JSON pointer has no parent | The JSON Patch operations 'remove' and 'add' can not be applied to the root element of the JSON value. -json.exception.out_of_range.406 | number overflow parsing '10E1000' | A parsed number could not be stored as without changing it to NaN or INF. +template +struct is_compatible_object_type_impl : std::false_type {}; -@since version 3.0.0 -*/ -class out_of_range : public exception +template +struct is_compatible_object_type_impl { - public: - static out_of_range create(int id, const std::string& what_arg) - { - std::string w = exception::name("out_of_range", id) + what_arg; - return out_of_range(id, w.c_str()); - } + static constexpr auto value = + std::is_constructible::value and + std::is_constructible::value; +}; - private: - out_of_range(int id_, const char* what_arg) - : exception(id_, what_arg) - {} +template +struct is_compatible_object_type +{ + static auto constexpr value = is_compatible_object_type_impl < + conjunction>, + has_mapped_type, + has_key_type>::value, + typename BasicJsonType::object_t, CompatibleObjectType >::value; }; -/*! -@brief exception indicating other errors +template +struct is_basic_json_nested_type +{ + static auto constexpr value = std::is_same::value or + std::is_same::value or + std::is_same::value or + std::is_same::value; +}; -Exceptions have ids 5xx. +template +struct is_compatible_array_type +{ + static auto constexpr value = + conjunction>, + negation>, + negation>, + negation>, + has_value_type, + has_iterator>::value; +}; -name / id | example massage | description ------------------------------- | --------------- | ------------------------- -json.exception.other_error.501 | unsuccessful: {"op":"test","path":"/baz", "value":"bar"} | A JSON Patch operation 'test' failed. The unsuccessful operation is also printed. +template +struct is_compatible_integer_type_impl : std::false_type {}; -@since version 3.0.0 -*/ -class other_error : public exception +template +struct is_compatible_integer_type_impl +{ + // is there an assert somewhere on overflows? + using RealLimits = std::numeric_limits; + using CompatibleLimits = std::numeric_limits; + + static constexpr auto value = + std::is_constructible::value and + CompatibleLimits::is_integer and + RealLimits::is_signed == CompatibleLimits::is_signed; +}; + +template +struct is_compatible_integer_type +{ + static constexpr auto value = + is_compatible_integer_type_impl < + std::is_integral::value and + not std::is_same::value, + RealIntegerType, CompatibleNumberIntegerType > ::value; +}; + +// trait checking if JSONSerializer::from_json(json const&, udt&) exists +template +struct has_from_json { + private: + // also check the return type of from_json + template::from_json( + std::declval(), std::declval()))>::value>> + static int detect(U&&); + static void detect(...); + public: - static other_error create(int id, const std::string& what_arg) - { - std::string w = exception::name("other_error", id) + what_arg; - return other_error(id, w.c_str()); - } + static constexpr bool value = std::is_integral>()))>::value; +}; +// This trait checks if JSONSerializer::from_json(json const&) exists +// this overload is used for non-default-constructible user-defined-types +template +struct has_non_default_from_json +{ private: - other_error(int id_, const char* what_arg) - : exception(id_, what_arg) - {} + template < + typename U, + typename = enable_if_t::from_json(std::declval()))>::value >> + static int detect(U&&); + static void detect(...); + + public: + static constexpr bool value = std::is_integral>()))>::value; }; +// This trait checks if BasicJsonType::json_serializer::to_json exists +template +struct has_to_json +{ + private: + template::to_json( + std::declval(), std::declval()))> + static int detect(U&&); + static void detect(...); + public: + static constexpr bool value = std::is_integral>()))>::value; +}; -/////////////////////////// -// JSON type enumeration // -/////////////////////////// +template +struct is_compatible_complete_type +{ + static constexpr bool value = + not std::is_base_of::value and + not is_basic_json::value and + not is_basic_json_nested_type::value and + has_to_json::value; +}; -/*! -@brief the JSON type enumeration +template +struct is_compatible_type + : conjunction, + is_compatible_complete_type> +{ +}; -This enumeration collects the different JSON types. It is internally used to -distinguish the stored values, and the functions @ref basic_json::is_null(), -@ref basic_json::is_object(), @ref basic_json::is_array(), -@ref basic_json::is_string(), @ref basic_json::is_boolean(), -@ref basic_json::is_number() (with @ref basic_json::is_number_integer(), -@ref basic_json::is_number_unsigned(), and @ref basic_json::is_number_float()), -@ref basic_json::is_discarded(), @ref basic_json::is_primitive(), and -@ref basic_json::is_structured() rely on it. +// taken from ranges-v3 +template +struct static_const +{ + static constexpr T value{}; +}; -@note There are three enumeration entries (number_integer, number_unsigned, and -number_float), because the library distinguishes these three types for numbers: -@ref basic_json::number_unsigned_t is used for unsigned integers, -@ref basic_json::number_integer_t is used for signed integers, and -@ref basic_json::number_float_t is used for floating-point numbers or to -approximate integers which do not fit in the limits of their respective type. +template +constexpr T static_const::value; +} +} -@sa @ref basic_json::basic_json(const value_t value_type) -- create a JSON -value with the default value for a given type +// #include -@since version 1.0.0 -*/ -enum class value_t : uint8_t -{ - null, ///< null value - object, ///< object (unordered set of name/value pairs) - array, ///< array (ordered collection of values) - string, ///< string value - boolean, ///< boolean value - number_integer, ///< number value (signed integer) - number_unsigned, ///< number value (unsigned integer) - number_float, ///< number value (floating-point) - discarded ///< discarded by the the parser callback function -}; + +#include // exception +#include // runtime_error +#include // to_string + +namespace nlohmann +{ +namespace detail +{ +//////////////// +// exceptions // +//////////////// /*! -@brief comparison operator for JSON types +@brief general exception of the @ref basic_json class -Returns an ordering that is similar to Python: -- order: null < boolean < number < object < array < string -- furthermore, each type is not smaller than itself +This class is an extension of `std::exception` objects with a member @a id for +exception ids. It is used as the base class for all exceptions thrown by the +@ref basic_json class. This class can hence be used as "wildcard" to catch +exceptions. -@since version 1.0.0 +Subclasses: +- @ref parse_error for exceptions indicating a parse error +- @ref invalid_iterator for exceptions indicating errors with iterators +- @ref type_error for exceptions indicating executing a member function with + a wrong type +- @ref out_of_range for exceptions indicating access out of the defined range +- @ref other_error for exceptions indicating other library errors + +@internal +@note To have nothrow-copy-constructible exceptions, we internally use + `std::runtime_error` which can cope with arbitrary-length error messages. + Intermediate strings are built with static functions and then passed to + the actual constructor. +@endinternal + +@liveexample{The following code shows how arbitrary library exceptions can be +caught.,exception} + +@since version 3.0.0 */ -inline bool operator<(const value_t lhs, const value_t rhs) noexcept +class exception : public std::exception { - static constexpr std::array order = {{ - 0, // null - 3, // object - 4, // array - 5, // string - 1, // boolean - 2, // integer - 2, // unsigned - 2, // float - } - }; - - // discarded values are not comparable - if (lhs == value_t::discarded or rhs == value_t::discarded) + public: + /// returns the explanatory string + const char* what() const noexcept override { - return false; + return m.what(); } - return order[static_cast(lhs)] < - order[static_cast(rhs)]; -} - + /// the id of the exception + const int id; -///////////// -// helpers // -///////////// + protected: + exception(int id_, const char* what_arg) : id(id_), m(what_arg) {} -// alias templates to reduce boilerplate -template -using enable_if_t = typename std::enable_if::type; + static std::string name(const std::string& ename, int id_) + { + return "[json.exception." + ename + "." + std::to_string(id_) + "] "; + } -template -using uncvref_t = typename std::remove_cv::type>::type; + private: + /// an exception object as storage for error messages + std::runtime_error m; +}; -/* -Implementation of two C++17 constructs: conjunction, negation. This is needed -to avoid evaluating all the traits in a condition +/*! +@brief exception indicating a parse error -For example: not std::is_same::value and has_value_type::value -will not compile when T = void (on MSVC at least). Whereas -conjunction>, has_value_type>::value will -stop evaluating if negation<...>::value == false +This exception is thrown by the library when a parse error occurs. Parse errors +can occur during the deserialization of JSON text, CBOR, MessagePack, as well +as when using JSON Patch. -Please note that those constructs must be used with caution, since symbols can -become very long quickly (which can slow down compilation and cause MSVC -internal compiler errors). Only use it when you have to (see example ahead). -*/ -template struct conjunction : std::true_type {}; -template struct conjunction : B1 {}; -template -struct conjunction : std::conditional, B1>::type {}; +Member @a byte holds the byte index of the last read character in the input +file. -template struct negation : std::integral_constant < bool, !B::value > {}; +Exceptions have ids 1xx. -// dispatch utility (taken from ranges-v3) -template struct priority_tag : priority_tag < N - 1 > {}; -template<> struct priority_tag<0> {}; +name / id | example message | description +------------------------------ | --------------- | ------------------------- +json.exception.parse_error.101 | parse error at 2: unexpected end of input; expected string literal | This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member @a byte indicates the error position. +json.exception.parse_error.102 | parse error at 14: missing or wrong low surrogate | JSON uses the `\uxxxx` format to describe Unicode characters. Code points above above 0xFFFF are split into two `\uxxxx` entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point. +json.exception.parse_error.103 | parse error: code points above 0x10FFFF are invalid | Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid. +json.exception.parse_error.104 | parse error: JSON patch must be an array of objects | [RFC 6902](https://tools.ietf.org/html/rfc6902) requires a JSON Patch document to be a JSON document that represents an array of objects. +json.exception.parse_error.105 | parse error: operation must have string member 'op' | An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors. +json.exception.parse_error.106 | parse error: array index '01' must not begin with '0' | An array index in a JSON Pointer ([RFC 6901](https://tools.ietf.org/html/rfc6901)) may be `0` or any number without a leading `0`. +json.exception.parse_error.107 | parse error: JSON pointer must be empty or begin with '/' - was: 'foo' | A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a `/` character. +json.exception.parse_error.108 | parse error: escape character '~' must be followed with '0' or '1' | In a JSON Pointer, only `~0` and `~1` are valid escape sequences. +json.exception.parse_error.109 | parse error: array index 'one' is not a number | A JSON Pointer array index must be a number. +json.exception.parse_error.110 | parse error at 1: cannot read 2 bytes from vector | When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read. +json.exception.parse_error.112 | parse error at 1: error reading CBOR; last byte: 0xF8 | Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read. +json.exception.parse_error.113 | parse error at 2: expected a CBOR string; last byte: 0x98 | While parsing a map key, a value that is not a string has been read. +@note For an input with n bytes, 1 is the index of the first character and n+1 + is the index of the terminating null byte or the end of file. This also + holds true when reading a byte vector (CBOR or MessagePack). -////////////////// -// constructors // -////////////////// +@liveexample{The following code shows how a `parse_error` exception can be +caught.,parse_error} -template struct external_constructor; +@sa @ref exception for the base class of the library exceptions +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref out_of_range for exceptions indicating access out of the defined range +@sa @ref other_error for exceptions indicating other library errors -template<> -struct external_constructor +@since version 3.0.0 +*/ +class parse_error : public exception { - template - static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept + public: + /*! + @brief create a parse error exception + @param[in] id_ the id of the exception + @param[in] byte_ the byte index where the error occurred (or 0 if the + position cannot be determined) + @param[in] what_arg the explanatory string + @return parse_error object + */ + static parse_error create(int id_, std::size_t byte_, const std::string& what_arg) { - j.m_type = value_t::boolean; - j.m_value = b; - j.assert_invariant(); + std::string w = exception::name("parse_error", id_) + "parse error" + + (byte_ != 0 ? (" at " + std::to_string(byte_)) : "") + + ": " + what_arg; + return parse_error(id_, byte_, w.c_str()); } -}; -template<> -struct external_constructor -{ - template - static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s) - { - j.m_type = value_t::string; - j.m_value = s; - j.assert_invariant(); - } -}; + /*! + @brief byte index of the parse error -template<> -struct external_constructor -{ - template - static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept - { - j.m_type = value_t::number_float; - j.m_value = val; - j.assert_invariant(); - } -}; + The byte index of the last read character in the input file. -template<> -struct external_constructor -{ - template - static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept - { - j.m_type = value_t::number_unsigned; - j.m_value = val; - j.assert_invariant(); - } + @note For an input with n bytes, 1 is the index of the first character and + n+1 is the index of the terminating null byte or the end of file. + This also holds true when reading a byte vector (CBOR or MessagePack). + */ + const std::size_t byte; + + private: + parse_error(int id_, std::size_t byte_, const char* what_arg) + : exception(id_, what_arg), byte(byte_) {} }; -template<> -struct external_constructor +/*! +@brief exception indicating errors with iterators + +This exception is thrown if iterators passed to a library function do not match +the expected semantics. + +Exceptions have ids 2xx. + +name / id | example message | description +----------------------------------- | --------------- | ------------------------- +json.exception.invalid_iterator.201 | iterators are not compatible | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. +json.exception.invalid_iterator.202 | iterator does not fit current value | In an erase or insert function, the passed iterator @a pos does not belong to the JSON value for which the function was called. It hence does not define a valid position for the deletion/insertion. +json.exception.invalid_iterator.203 | iterators do not fit current value | Either iterator passed to function @ref erase(IteratorType first, IteratorType last) does not belong to the JSON value from which values shall be erased. It hence does not define a valid range to delete values from. +json.exception.invalid_iterator.204 | iterators out of range | When an iterator range for a primitive type (number, boolean, or string) is passed to a constructor or an erase function, this range has to be exactly (@ref begin(), @ref end()), because this is the only way the single stored value is expressed. All other ranges are invalid. +json.exception.invalid_iterator.205 | iterator out of range | When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the @ref begin() iterator, because it is the only way to address the stored value. All other iterators are invalid. +json.exception.invalid_iterator.206 | cannot construct with iterators from null | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range. +json.exception.invalid_iterator.207 | cannot use key() for non-object iterators | The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key. +json.exception.invalid_iterator.208 | cannot use operator[] for object iterators | The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. +json.exception.invalid_iterator.209 | cannot use offsets with object iterators | The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. +json.exception.invalid_iterator.210 | iterators do not fit | The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. +json.exception.invalid_iterator.211 | passed iterators may not belong to container | The iterator range passed to the insert function must not be a subrange of the container to insert to. +json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container. +json.exception.invalid_iterator.213 | cannot compare order of object iterators | The order of object iterators cannot be compared, because JSON objects are unordered. +json.exception.invalid_iterator.214 | cannot get value | Cannot get value for iterator: Either the iterator belongs to a null value or it is an iterator to a primitive type (number, boolean, or string), but the iterator is different to @ref begin(). + +@liveexample{The following code shows how an `invalid_iterator` exception can be +caught.,invalid_iterator} + +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref out_of_range for exceptions indicating access out of the defined range +@sa @ref other_error for exceptions indicating other library errors + +@since version 3.0.0 +*/ +class invalid_iterator : public exception { - template - static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept + public: + static invalid_iterator create(int id_, const std::string& what_arg) { - j.m_type = value_t::number_integer; - j.m_value = val; - j.assert_invariant(); + std::string w = exception::name("invalid_iterator", id_) + what_arg; + return invalid_iterator(id_, w.c_str()); } + + private: + invalid_iterator(int id_, const char* what_arg) + : exception(id_, what_arg) {} }; -template<> -struct external_constructor -{ - template - static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr) - { - j.m_type = value_t::array; - j.m_value = arr; - j.assert_invariant(); - } +/*! +@brief exception indicating executing a member function with a wrong type - template::value, - int> = 0> - static void construct(BasicJsonType& j, const CompatibleArrayType& arr) - { - using std::begin; - using std::end; - j.m_type = value_t::array; - j.m_value.array = j.template create(begin(arr), end(arr)); - j.assert_invariant(); - } +This exception is thrown in case of a type error; that is, a library function is +executed on a JSON value whose type does not match the expected semantics. - template - static void construct(BasicJsonType& j, const std::vector& arr) - { - j.m_type = value_t::array; - j.m_value = value_t::array; - j.m_value.array->reserve(arr.size()); - for (bool x : arr) - { - j.m_value.array->push_back(x); - } - j.assert_invariant(); - } -}; +Exceptions have ids 3xx. -template<> -struct external_constructor +name / id | example message | description +----------------------------- | --------------- | ------------------------- +json.exception.type_error.301 | cannot create object from initializer list | To create an object from an initializer list, the initializer list must consist only of a list of pairs whose first element is a string. When this constraint is violated, an array is created instead. +json.exception.type_error.302 | type must be object, but is array | During implicit or explicit value conversion, the JSON type must be compatible to the target type. For instance, a JSON string can only be converted into string types, but not into numbers or boolean types. +json.exception.type_error.303 | incompatible ReferenceType for get_ref, actual type is object | To retrieve a reference to a value stored in a @ref basic_json object with @ref get_ref, the type of the reference must match the value type. For instance, for a JSON array, the @a ReferenceType must be @ref array_t&. +json.exception.type_error.304 | cannot use at() with string | The @ref at() member functions can only be executed for certain JSON types. +json.exception.type_error.305 | cannot use operator[] with string | The @ref operator[] member functions can only be executed for certain JSON types. +json.exception.type_error.306 | cannot use value() with string | The @ref value() member functions can only be executed for certain JSON types. +json.exception.type_error.307 | cannot use erase() with string | The @ref erase() member functions can only be executed for certain JSON types. +json.exception.type_error.308 | cannot use push_back() with string | The @ref push_back() and @ref operator+= member functions can only be executed for certain JSON types. +json.exception.type_error.309 | cannot use insert() with | The @ref insert() member functions can only be executed for certain JSON types. +json.exception.type_error.310 | cannot use swap() with number | The @ref swap() member functions can only be executed for certain JSON types. +json.exception.type_error.311 | cannot use emplace_back() with string | The @ref emplace_back() member function can only be executed for certain JSON types. +json.exception.type_error.312 | cannot use update() with string | The @ref update() member functions can only be executed for certain JSON types. +json.exception.type_error.313 | invalid value to unflatten | The @ref unflatten function converts an object whose keys are JSON Pointers back into an arbitrary nested JSON value. The JSON Pointers must not overlap, because then the resulting value would not be well defined. +json.exception.type_error.314 | only objects can be unflattened | The @ref unflatten function only works for an object whose keys are JSON Pointers. +json.exception.type_error.315 | values in object must be primitive | The @ref unflatten function only works for an object whose keys are JSON Pointers and whose values are primitive. +json.exception.type_error.316 | invalid UTF-8 byte at index 10: 0x7E | The @ref dump function only works with UTF-8 encoded strings; that is, if you assign a `std::string` to a JSON value, make sure it is UTF-8 encoded. | + +@liveexample{The following code shows how a `type_error` exception can be +caught.,type_error} + +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref out_of_range for exceptions indicating access out of the defined range +@sa @ref other_error for exceptions indicating other library errors + +@since version 3.0.0 +*/ +class type_error : public exception { - template - static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj) + public: + static type_error create(int id_, const std::string& what_arg) { - j.m_type = value_t::object; - j.m_value = obj; - j.assert_invariant(); + std::string w = exception::name("type_error", id_) + what_arg; + return type_error(id_, w.c_str()); } - template::value, - int> = 0> - static void construct(BasicJsonType& j, const CompatibleObjectType& obj) - { - using std::begin; - using std::end; - - j.m_type = value_t::object; - j.m_value.object = j.template create(begin(obj), end(obj)); - j.assert_invariant(); - } + private: + type_error(int id_, const char* what_arg) : exception(id_, what_arg) {} }; +/*! +@brief exception indicating access out of the defined range -//////////////////////// -// has_/is_ functions // -//////////////////////// +This exception is thrown in case a library function is called on an input +parameter that exceeds the expected range, for instance in case of array +indices or nonexisting object keys. -/*! -@brief Helper to determine whether there's a key_type for T. +Exceptions have ids 4xx. -This helper is used to tell associative containers apart from other containers -such as sequence containers. For instance, `std::map` passes the test as it -contains a `mapped_type`, whereas `std::vector` fails the test. +name / id | example message | description +------------------------------- | --------------- | ------------------------- +json.exception.out_of_range.401 | array index 3 is out of range | The provided array index @a i is larger than @a size-1. +json.exception.out_of_range.402 | array index '-' (3) is out of range | The special array index `-` in a JSON Pointer never describes a valid element of the array, but the index past the end. That is, it can only be used to add elements at this position, but not to read it. +json.exception.out_of_range.403 | key 'foo' not found | The provided key was not found in the JSON object. +json.exception.out_of_range.404 | unresolved reference token 'foo' | A reference token in a JSON Pointer could not be resolved. +json.exception.out_of_range.405 | JSON pointer has no parent | The JSON Patch operations 'remove' and 'add' can not be applied to the root element of the JSON value. +json.exception.out_of_range.406 | number overflow parsing '10E1000' | A parsed number could not be stored as without changing it to NaN or INF. +json.exception.out_of_range.407 | number overflow serializing '9223372036854775808' | UBJSON only supports integers numbers up to 9223372036854775807. | +json.exception.out_of_range.408 | excessive array size: 8658170730974374167 | The size (following `#`) of an UBJSON array or object exceeds the maximal capacity. | -@sa http://stackoverflow.com/a/7728728/266378 -@since version 1.0.0, overworked in version 2.0.6 +@liveexample{The following code shows how an `out_of_range` exception can be +caught.,out_of_range} + +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref other_error for exceptions indicating other library errors + +@since version 3.0.0 */ -#define NLOHMANN_JSON_HAS_HELPER(type) \ - template struct has_##type { \ - private: \ - template \ - static int detect(U &&); \ - static void detect(...); \ - public: \ - static constexpr bool value = \ - std::is_integral()))>::value; \ +class out_of_range : public exception +{ + public: + static out_of_range create(int id_, const std::string& what_arg) + { + std::string w = exception::name("out_of_range", id_) + what_arg; + return out_of_range(id_, w.c_str()); } -NLOHMANN_JSON_HAS_HELPER(mapped_type); -NLOHMANN_JSON_HAS_HELPER(key_type); -NLOHMANN_JSON_HAS_HELPER(value_type); -NLOHMANN_JSON_HAS_HELPER(iterator); + private: + out_of_range(int id_, const char* what_arg) : exception(id_, what_arg) {} +}; -#undef NLOHMANN_JSON_HAS_HELPER +/*! +@brief exception indicating other library errors +This exception is thrown in case of errors that cannot be classified with the +other exception types. -template -struct is_compatible_object_type_impl : std::false_type {}; +Exceptions have ids 5xx. -template -struct is_compatible_object_type_impl -{ - static constexpr auto value = - std::is_constructible::value and - std::is_constructible::value; -}; +name / id | example message | description +------------------------------ | --------------- | ------------------------- +json.exception.other_error.501 | unsuccessful: {"op":"test","path":"/baz", "value":"bar"} | A JSON Patch operation 'test' failed. The unsuccessful operation is also printed. -template -struct is_compatible_object_type -{ - static auto constexpr value = is_compatible_object_type_impl < - conjunction>, - has_mapped_type, - has_key_type>::value, - typename BasicJsonType::object_t, CompatibleObjectType >::value; -}; +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref out_of_range for exceptions indicating access out of the defined range -template -struct is_basic_json_nested_type -{ - static auto constexpr value = std::is_same::value or - std::is_same::value or - std::is_same::value or - std::is_same::value or - std::is_same::value; -}; +@liveexample{The following code shows how an `other_error` exception can be +caught.,other_error} -template -struct is_compatible_array_type +@since version 3.0.0 +*/ +class other_error : public exception { - static auto constexpr value = - conjunction>, - negation>, - negation>, - negation>, - has_value_type, - has_iterator>::value; + public: + static other_error create(int id_, const std::string& what_arg) + { + std::string w = exception::name("other_error", id_) + what_arg; + return other_error(id_, w.c_str()); + } + + private: + other_error(int id_, const char* what_arg) : exception(id_, what_arg) {} }; +} +} -template -struct is_compatible_integer_type_impl : std::false_type {}; +// #include -template -struct is_compatible_integer_type_impl -{ - // is there an assert somewhere on overflows? - using RealLimits = std::numeric_limits; - using CompatibleLimits = std::numeric_limits; - static constexpr auto value = - std::is_constructible::value and - CompatibleLimits::is_integer and - RealLimits::is_signed == CompatibleLimits::is_signed; -}; +#include // array +#include // and +#include // size_t +#include // uint8_t -template -struct is_compatible_integer_type +namespace nlohmann { - static constexpr auto value = - is_compatible_integer_type_impl < - std::is_integral::value and - not std::is_same::value, - RealIntegerType, CompatibleNumberIntegerType > ::value; -}; - - -// trait checking if JSONSerializer::from_json(json const&, udt&) exists -template -struct has_from_json +namespace detail { - private: - // also check the return type of from_json - template::from_json( - std::declval(), std::declval()))>::value>> - static int detect(U&&); - static void detect(...); +/////////////////////////// +// JSON type enumeration // +/////////////////////////// - public: - static constexpr bool value = std::is_integral>()))>::value; -}; +/*! +@brief the JSON type enumeration -// This trait checks if JSONSerializer::from_json(json const&) exists -// this overload is used for non-default-constructible user-defined-types -template -struct has_non_default_from_json -{ - private: - template < - typename U, - typename = enable_if_t::from_json(std::declval()))>::value >> - static int detect(U&&); - static void detect(...); +This enumeration collects the different JSON types. It is internally used to +distinguish the stored values, and the functions @ref basic_json::is_null(), +@ref basic_json::is_object(), @ref basic_json::is_array(), +@ref basic_json::is_string(), @ref basic_json::is_boolean(), +@ref basic_json::is_number() (with @ref basic_json::is_number_integer(), +@ref basic_json::is_number_unsigned(), and @ref basic_json::is_number_float()), +@ref basic_json::is_discarded(), @ref basic_json::is_primitive(), and +@ref basic_json::is_structured() rely on it. - public: - static constexpr bool value = std::is_integral>()))>::value; -}; +@note There are three enumeration entries (number_integer, number_unsigned, and +number_float), because the library distinguishes these three types for numbers: +@ref basic_json::number_unsigned_t is used for unsigned integers, +@ref basic_json::number_integer_t is used for signed integers, and +@ref basic_json::number_float_t is used for floating-point numbers or to +approximate integers which do not fit in the limits of their respective type. -// This trait checks if BasicJsonType::json_serializer::to_json exists -template -struct has_to_json -{ - private: - template::to_json( - std::declval(), std::declval()))> - static int detect(U&&); - static void detect(...); +@sa @ref basic_json::basic_json(const value_t value_type) -- create a JSON +value with the default value for a given type - public: - static constexpr bool value = std::is_integral>()))>::value; +@since version 1.0.0 +*/ +enum class value_t : std::uint8_t +{ + null, ///< null value + object, ///< object (unordered set of name/value pairs) + array, ///< array (ordered collection of values) + string, ///< string value + boolean, ///< boolean value + number_integer, ///< number value (signed integer) + number_unsigned, ///< number value (unsigned integer) + number_float, ///< number value (floating-point) + discarded ///< discarded by the the parser callback function }; +/*! +@brief comparison operator for JSON types -///////////// -// to_json // -///////////// +Returns an ordering that is similar to Python: +- order: null < boolean < number < object < array < string +- furthermore, each type is not smaller than itself +- discarded values are not comparable -template::value, int> = 0> -void to_json(BasicJsonType& j, T b) noexcept +@since version 1.0.0 +*/ +inline bool operator<(const value_t lhs, const value_t rhs) noexcept { - external_constructor::construct(j, b); -} + static constexpr std::array order = {{ + 0 /* null */, 3 /* object */, 4 /* array */, 5 /* string */, + 1 /* boolean */, 2 /* integer */, 2 /* unsigned */, 2 /* float */ + } + }; -template::value, int> = 0> -void to_json(BasicJsonType& j, const CompatibleString& s) -{ - external_constructor::construct(j, s); + const auto l_index = static_cast(lhs); + const auto r_index = static_cast(rhs); + return l_index < order.size() and r_index < order.size() and order[l_index] < order[r_index]; } - -template::value, int> = 0> -void to_json(BasicJsonType& j, FloatType val) noexcept -{ - external_constructor::construct(j, static_cast(val)); } - -template < - typename BasicJsonType, typename CompatibleNumberUnsignedType, - enable_if_t::value, int> = 0 > -void to_json(BasicJsonType& j, CompatibleNumberUnsignedType val) noexcept -{ - external_constructor::construct(j, static_cast(val)); } -template < - typename BasicJsonType, typename CompatibleNumberIntegerType, - enable_if_t::value, int> = 0 > -void to_json(BasicJsonType& j, CompatibleNumberIntegerType val) noexcept -{ - external_constructor::construct(j, static_cast(val)); -} +// #include -template::value, int> = 0> -void to_json(BasicJsonType& j, EnumType e) noexcept -{ - using underlying_type = typename std::underlying_type::type; - external_constructor::construct(j, static_cast(e)); -} -template -void to_json(BasicJsonType& j, const std::vector& e) -{ - external_constructor::construct(j, e); -} +#include // transform +#include // array +#include // and, not +#include // forward_list +#include // inserter, front_inserter, end +#include // map +#include // string +#include // tuple, make_tuple +#include // is_arithmetic, is_same, is_enum, underlying_type, is_convertible +#include // pair, declval +#include // valarray -template < - typename BasicJsonType, typename CompatibleArrayType, - enable_if_t < - is_compatible_array_type::value or - std::is_same::value, - int > = 0 > -void to_json(BasicJsonType& j, const CompatibleArrayType& arr) -{ - external_constructor::construct(j, arr); -} +// #include -template < - typename BasicJsonType, typename CompatibleObjectType, - enable_if_t::value, - int> = 0 > -void to_json(BasicJsonType& j, const CompatibleObjectType& arr) -{ - external_constructor::construct(j, arr); -} +// #include -template ::value, - int> = 0> -void to_json(BasicJsonType& j, T (&arr)[N]) -{ - external_constructor::construct(j, arr); -} +// #include + +// #include -/////////////// -// from_json // -/////////////// +namespace nlohmann +{ +namespace detail +{ // overloads for basic_json template parameters template::value and - not std::is_same::value, + not std::is_same::value, int> = 0> void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val) { @@ -881,35 +940,31 @@ void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val) { case value_t::number_unsigned: { - val = static_cast( - *j.template get_ptr()); + val = static_cast(*j.template get_ptr()); break; } case value_t::number_integer: { - val = static_cast( - *j.template get_ptr()); + val = static_cast(*j.template get_ptr()); break; } case value_t::number_float: { - val = static_cast( - *j.template get_ptr()); + val = static_cast(*j.template get_ptr()); break; } + default: - { - JSON_THROW(type_error::create(302, "type must be number, but is " + j.type_name())); - } + JSON_THROW(type_error::create(302, "type must be number, but is " + std::string(j.type_name()))); } } template void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b) { - if (not j.is_boolean()) + if (JSON_UNLIKELY(not j.is_boolean())) { - JSON_THROW(type_error::create(302, "type must be boolean, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be boolean, but is " + std::string(j.type_name()))); } b = *j.template get_ptr(); } @@ -917,9 +972,9 @@ void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b) template void from_json(const BasicJsonType& j, typename BasicJsonType::string_t& s) { - if (not j.is_string()) + if (JSON_UNLIKELY(not j.is_string())) { - JSON_THROW(type_error::create(302, "type must be string, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be string, but is " + std::string(j.type_name()))); } s = *j.template get_ptr(); } @@ -954,9 +1009,9 @@ void from_json(const BasicJsonType& j, EnumType& e) template void from_json(const BasicJsonType& j, typename BasicJsonType::array_t& arr) { - if (not j.is_array()) + if (JSON_UNLIKELY(not j.is_array())) { - JSON_THROW(type_error::create(302, "type must be array, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } arr = *j.template get_ptr(); } @@ -966,21 +1021,33 @@ template::value, int> = 0> void from_json(const BasicJsonType& j, std::forward_list& l) { - if (not j.is_array()) + if (JSON_UNLIKELY(not j.is_array())) { - JSON_THROW(type_error::create(302, "type must be array, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } + std::transform(j.rbegin(), j.rend(), + std::front_inserter(l), [](const BasicJsonType & i) + { + return i.template get(); + }); +} - for (auto it = j.rbegin(), end = j.rend(); it != end; ++it) +// valarray doesn't have an insert method +template::value, int> = 0> +void from_json(const BasicJsonType& j, std::valarray& l) +{ + if (JSON_UNLIKELY(not j.is_array())) { - l.push_front(it->template get()); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } + l.resize(j.size()); + std::copy(j.m_value.array->begin(), j.m_value.array->end(), std::begin(l)); } template -void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<0>) +void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<0> /*unused*/) { - using std::begin; using std::end; std::transform(j.begin(), j.end(), @@ -993,12 +1060,11 @@ void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, prio } template -auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<1>) +auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<1> /*unused*/) -> decltype( arr.reserve(std::declval()), void()) { - using std::begin; using std::end; arr.reserve(j.size()); @@ -1011,36 +1077,53 @@ auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, prio }); } -template::value and - std::is_convertible::value and - not std::is_same::value, int> = 0> +template +void from_json_array_impl(const BasicJsonType& j, std::array& arr, priority_tag<2> /*unused*/) +{ + for (std::size_t i = 0; i < N; ++i) + { + arr[i] = j.at(i).template get(); + } +} + +template < + typename BasicJsonType, typename CompatibleArrayType, + enable_if_t < + is_compatible_array_type::value and + not std::is_same::value and + std::is_constructible < + BasicJsonType, typename CompatibleArrayType::value_type >::value, + int > = 0 > void from_json(const BasicJsonType& j, CompatibleArrayType& arr) { - if (not j.is_array()) + if (JSON_UNLIKELY(not j.is_array())) { - JSON_THROW(type_error::create(302, "type must be array, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be array, but is " + + std::string(j.type_name()))); } - from_json_array_impl(j, arr, priority_tag<1> {}); + from_json_array_impl(j, arr, priority_tag<2> {}); } template::value, int> = 0> void from_json(const BasicJsonType& j, CompatibleObjectType& obj) { - if (not j.is_object()) + if (JSON_UNLIKELY(not j.is_object())) { - JSON_THROW(type_error::create(302, "type must be object, but is " + j.type_name())); + JSON_THROW(type_error::create(302, "type must be object, but is " + std::string(j.type_name()))); } auto inner_object = j.template get_ptr(); - using std::begin; - using std::end; - // we could avoid the assignment, but this might require a for loop, which - // might be less efficient than the container constructor for some - // containers (would it?) - obj = CompatibleObjectType(begin(*inner_object), end(*inner_object)); + using value_type = typename CompatibleObjectType::value_type; + std::transform( + inner_object->begin(), inner_object->end(), + std::inserter(obj, obj.begin()), + [](typename BasicJsonType::object_t::value_type const & p) + { + return value_type(p.first, p.second.template get()); + }); } // overload for arithmetic types, not chosen for basic_json template arguments @@ -1079,44 +1162,54 @@ void from_json(const BasicJsonType& j, ArithmeticType& val) val = static_cast(*j.template get_ptr()); break; } + default: - { - JSON_THROW(type_error::create(302, "type must be number, but is " + j.type_name())); - } + JSON_THROW(type_error::create(302, "type must be number, but is " + std::string(j.type_name()))); } } -struct to_json_fn +template +void from_json(const BasicJsonType& j, std::pair& p) { - private: - template - auto call(BasicJsonType& j, T&& val, priority_tag<1>) const noexcept(noexcept(to_json(j, std::forward(val)))) - -> decltype(to_json(j, std::forward(val)), void()) - { - return to_json(j, std::forward(val)); - } + p = {j.at(0).template get(), j.at(1).template get()}; +} - template - void call(BasicJsonType&, T&&, priority_tag<0>) const noexcept +template +void from_json_tuple_impl(const BasicJsonType& j, Tuple& t, index_sequence) +{ + t = std::make_tuple(j.at(Idx).template get::type>()...); +} + +template +void from_json(const BasicJsonType& j, std::tuple& t) +{ + from_json_tuple_impl(j, t, index_sequence_for {}); +} + +template ::value>> +void from_json(const BasicJsonType& j, std::map& m) +{ + if (JSON_UNLIKELY(not j.is_array())) { - static_assert(sizeof(BasicJsonType) == 0, - "could not find to_json() method in T's namespace"); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } - - public: - template - void operator()(BasicJsonType& j, T&& val) const - noexcept(noexcept(std::declval().call(j, std::forward(val), priority_tag<1> {}))) + for (const auto& p : j) { - return call(j, std::forward(val), priority_tag<1> {}); + if (JSON_UNLIKELY(not p.is_array())) + { + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(p.type_name()))); + } + m.emplace(p.at(0).template get(), p.at(1).template get()); } -}; +} struct from_json_fn { private: template - auto call(const BasicJsonType& j, T& val, priority_tag<1>) const + auto call(const BasicJsonType& j, T& val, priority_tag<1> /*unused*/) const noexcept(noexcept(from_json(j, val))) -> decltype(from_json(j, val), void()) { @@ -1124,10 +1217,16 @@ struct from_json_fn } template - void call(const BasicJsonType&, T&, priority_tag<0>) const noexcept + void call(const BasicJsonType& /*unused*/, T& /*unused*/, priority_tag<0> /*unused*/) const noexcept { static_assert(sizeof(BasicJsonType) == 0, "could not find from_json() method in T's namespace"); +#ifdef _MSC_VER + // MSVC does not show a stacktrace for the above assert + using decayed = uncvref_t; + static_assert(sizeof(typename decayed::force_msvc_stacktrace) == 0, + "forcing MSVC stacktrace to show which T we're talking about."); +#endif } public: @@ -1138,12521 +1237,16353 @@ struct from_json_fn return call(j, val, priority_tag<1> {}); } }; +} -// taken from ranges-v3 -template -struct static_const -{ - static constexpr T value{}; -}; - -template -constexpr T static_const::value; -} // namespace detail - - -/// namespace to hold default `to_json` / `from_json` functions +/// namespace to hold default `from_json` function +/// to see why this is required: +/// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4381.html namespace { -constexpr const auto& to_json = detail::static_const::value; constexpr const auto& from_json = detail::static_const::value; } +} +// #include -/*! -@brief default JSONSerializer template argument -This serializer ignores the template arguments and uses ADL -([argument-dependent lookup](http://en.cppreference.com/w/cpp/language/adl)) -for serialization. -*/ -template -struct adl_serializer +#include // or, and, not +#include // begin, end +#include // tuple, get +#include // is_same, is_constructible, is_floating_point, is_enum, underlying_type +#include // move, forward, declval, pair +#include // valarray +#include // vector + +// #include + +// #include + + +namespace nlohmann { - /*! - @brief convert a JSON value to any value type +namespace detail +{ +////////////////// +// constructors // +////////////////// - This function is usually called by the `get()` function of the - @ref basic_json class (either explicit or via conversion operators). +template struct external_constructor; - @param[in] j JSON value to read from - @param[in,out] val value to write to - */ - template - static void from_json(BasicJsonType&& j, ValueType& val) noexcept( - noexcept(::nlohmann::from_json(std::forward(j), val))) +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept { - ::nlohmann::from_json(std::forward(j), val); + j.m_type = value_t::boolean; + j.m_value = b; + j.assert_invariant(); + } +}; + +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s) + { + j.m_type = value_t::string; + j.m_value = s; + j.assert_invariant(); + } + + template + static void construct(BasicJsonType& j, typename BasicJsonType::string_t&& s) + { + j.m_type = value_t::string; + j.m_value = std::move(s); + j.assert_invariant(); + } +}; + +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept + { + j.m_type = value_t::number_float; + j.m_value = val; + j.assert_invariant(); + } +}; + +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept + { + j.m_type = value_t::number_unsigned; + j.m_value = val; + j.assert_invariant(); + } +}; + +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept + { + j.m_type = value_t::number_integer; + j.m_value = val; + j.assert_invariant(); + } +}; + +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr) + { + j.m_type = value_t::array; + j.m_value = arr; + j.assert_invariant(); + } + + template + static void construct(BasicJsonType& j, typename BasicJsonType::array_t&& arr) + { + j.m_type = value_t::array; + j.m_value = std::move(arr); + j.assert_invariant(); + } + + template::value, + int> = 0> + static void construct(BasicJsonType& j, const CompatibleArrayType& arr) + { + using std::begin; + using std::end; + j.m_type = value_t::array; + j.m_value.array = j.template create(begin(arr), end(arr)); + j.assert_invariant(); + } + + template + static void construct(BasicJsonType& j, const std::vector& arr) + { + j.m_type = value_t::array; + j.m_value = value_t::array; + j.m_value.array->reserve(arr.size()); + for (const bool x : arr) + { + j.m_value.array->push_back(x); + } + j.assert_invariant(); + } + + template::value, int> = 0> + static void construct(BasicJsonType& j, const std::valarray& arr) + { + j.m_type = value_t::array; + j.m_value = value_t::array; + j.m_value.array->resize(arr.size()); + std::copy(std::begin(arr), std::end(arr), j.m_value.array->begin()); + j.assert_invariant(); + } +}; + +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj) + { + j.m_type = value_t::object; + j.m_value = obj; + j.assert_invariant(); + } + + template + static void construct(BasicJsonType& j, typename BasicJsonType::object_t&& obj) + { + j.m_type = value_t::object; + j.m_value = std::move(obj); + j.assert_invariant(); + } + + template::value, int> = 0> + static void construct(BasicJsonType& j, const CompatibleObjectType& obj) + { + using std::begin; + using std::end; + + j.m_type = value_t::object; + j.m_value.object = j.template create(begin(obj), end(obj)); + j.assert_invariant(); + } +}; + +///////////// +// to_json // +///////////// + +template::value, int> = 0> +void to_json(BasicJsonType& j, T b) noexcept +{ + external_constructor::construct(j, b); +} + +template::value, int> = 0> +void to_json(BasicJsonType& j, const CompatibleString& s) +{ + external_constructor::construct(j, s); +} + +template +void to_json(BasicJsonType& j, typename BasicJsonType::string_t&& s) +{ + external_constructor::construct(j, std::move(s)); +} + +template::value, int> = 0> +void to_json(BasicJsonType& j, FloatType val) noexcept +{ + external_constructor::construct(j, static_cast(val)); +} + +template::value, int> = 0> +void to_json(BasicJsonType& j, CompatibleNumberUnsignedType val) noexcept +{ + external_constructor::construct(j, static_cast(val)); +} + +template::value, int> = 0> +void to_json(BasicJsonType& j, CompatibleNumberIntegerType val) noexcept +{ + external_constructor::construct(j, static_cast(val)); +} + +template::value, int> = 0> +void to_json(BasicJsonType& j, EnumType e) noexcept +{ + using underlying_type = typename std::underlying_type::type; + external_constructor::construct(j, static_cast(e)); +} + +template +void to_json(BasicJsonType& j, const std::vector& e) +{ + external_constructor::construct(j, e); +} + +template::value or + std::is_same::value, + int> = 0> +void to_json(BasicJsonType& j, const CompatibleArrayType& arr) +{ + external_constructor::construct(j, arr); +} + +template::value, int> = 0> +void to_json(BasicJsonType& j, std::valarray arr) +{ + external_constructor::construct(j, std::move(arr)); +} + +template +void to_json(BasicJsonType& j, typename BasicJsonType::array_t&& arr) +{ + external_constructor::construct(j, std::move(arr)); +} + +template::value, int> = 0> +void to_json(BasicJsonType& j, const CompatibleObjectType& obj) +{ + external_constructor::construct(j, obj); +} + +template +void to_json(BasicJsonType& j, typename BasicJsonType::object_t&& obj) +{ + external_constructor::construct(j, std::move(obj)); +} + +template::value, int> = 0> +void to_json(BasicJsonType& j, T (&arr)[N]) +{ + external_constructor::construct(j, arr); +} + +template +void to_json(BasicJsonType& j, const std::pair& p) +{ + j = {p.first, p.second}; +} + +template +void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence) +{ + j = {std::get(t)...}; +} + +template +void to_json(BasicJsonType& j, const std::tuple& t) +{ + to_json_tuple_impl(j, t, index_sequence_for {}); +} + +struct to_json_fn +{ + private: + template + auto call(BasicJsonType& j, T&& val, priority_tag<1> /*unused*/) const noexcept(noexcept(to_json(j, std::forward(val)))) + -> decltype(to_json(j, std::forward(val)), void()) + { + return to_json(j, std::forward(val)); + } + + template + void call(BasicJsonType& /*unused*/, T&& /*unused*/, priority_tag<0> /*unused*/) const noexcept + { + static_assert(sizeof(BasicJsonType) == 0, + "could not find to_json() method in T's namespace"); + +#ifdef _MSC_VER + // MSVC does not show a stacktrace for the above assert + using decayed = uncvref_t; + static_assert(sizeof(typename decayed::force_msvc_stacktrace) == 0, + "forcing MSVC stacktrace to show which T we're talking about."); +#endif + } + + public: + template + void operator()(BasicJsonType& j, T&& val) const + noexcept(noexcept(std::declval().call(j, std::forward(val), priority_tag<1> {}))) + { + return call(j, std::forward(val), priority_tag<1> {}); + } +}; +} + +/// namespace to hold default `to_json` function +namespace +{ +constexpr const auto& to_json = detail::static_const::value; +} +} + +// #include + + +#include // assert +#include // size_t +#include // strlen +#include // istream +#include // begin, end, iterator_traits, random_access_iterator_tag, distance, next +#include // shared_ptr, make_shared, addressof +#include // accumulate +#include // string, char_traits +#include // enable_if, is_base_of, is_pointer, is_integral, remove_pointer +#include // pair, declval + +// #include + + +namespace nlohmann +{ +namespace detail +{ +/// the supported input formats +enum class input_format_t { json, cbor, msgpack, ubjson }; + +//////////////////// +// input adapters // +//////////////////// + +/*! +@brief abstract input adapter interface + +Produces a stream of std::char_traits::int_type characters from a +std::istream, a buffer, or some other input type. Accepts the return of +exactly one non-EOF character for future input. The int_type characters +returned consist of all valid char values as positive values (typically +unsigned char), plus an EOF value outside that range, specified by the value +of the function std::char_traits::eof(). This value is typically -1, but +could be any arbitrary value which is not a valid char value. +*/ +struct input_adapter_protocol +{ + /// get a character [0,255] or std::char_traits::eof(). + virtual std::char_traits::int_type get_character() = 0; + virtual ~input_adapter_protocol() = default; +}; + +/// a type to simplify interfaces +using input_adapter_t = std::shared_ptr; + +/*! +Input adapter for a (caching) istream. Ignores a UFT Byte Order Mark at +beginning of input. Does not support changing the underlying std::streambuf +in mid-input. Maintains underlying std::istream and std::streambuf to support +subsequent use of standard std::istream operations to process any input +characters following those used in parsing the JSON input. Clears the +std::istream flags; any input errors (e.g., EOF) will be detected by the first +subsequent call for input from the std::istream. +*/ +class input_stream_adapter : public input_adapter_protocol +{ + public: + ~input_stream_adapter() override + { + // clear stream flags; we use underlying streambuf I/O, do not + // maintain ifstream flags + is.clear(); + } + + explicit input_stream_adapter(std::istream& i) + : is(i), sb(*i.rdbuf()) + {} + + // delete because of pointer members + input_stream_adapter(const input_stream_adapter&) = delete; + input_stream_adapter& operator=(input_stream_adapter&) = delete; + + // std::istream/std::streambuf use std::char_traits::to_int_type, to + // ensure that std::char_traits::eof() and the character 0xFF do not + // end up as the same value, eg. 0xFFFFFFFF. + std::char_traits::int_type get_character() override + { + return sb.sbumpc(); + } + + private: + /// the associated input stream + std::istream& is; + std::streambuf& sb; +}; + +/// input adapter for buffer input +class input_buffer_adapter : public input_adapter_protocol +{ + public: + input_buffer_adapter(const char* b, const std::size_t l) + : cursor(b), limit(b + l) + {} + + // delete because of pointer members + input_buffer_adapter(const input_buffer_adapter&) = delete; + input_buffer_adapter& operator=(input_buffer_adapter&) = delete; + + std::char_traits::int_type get_character() noexcept override + { + if (JSON_LIKELY(cursor < limit)) + { + return std::char_traits::to_int_type(*(cursor++)); + } + + return std::char_traits::eof(); + } + + private: + /// pointer to the current character + const char* cursor; + /// pointer past the last character + const char* const limit; +}; + +template +class wide_string_input_adapter : public input_adapter_protocol +{ + public: + wide_string_input_adapter(const WideStringType& w) : str(w) {} + + std::char_traits::int_type get_character() noexcept override + { + // check if buffer needs to be filled + if (utf8_bytes_index == utf8_bytes_filled) + { + if (sizeof(typename WideStringType::value_type) == 2) + { + fill_buffer_utf16(); + } + else + { + fill_buffer_utf32(); + } + + assert(utf8_bytes_filled > 0); + assert(utf8_bytes_index == 0); + } + + // use buffer + assert(utf8_bytes_filled > 0); + assert(utf8_bytes_index < utf8_bytes_filled); + return utf8_bytes[utf8_bytes_index++]; + } + + private: + void fill_buffer_utf16() + { + utf8_bytes_index = 0; + + if (current_wchar == str.size()) + { + utf8_bytes[0] = std::char_traits::eof(); + utf8_bytes_filled = 1; + } + else + { + // get the current character + const int wc = static_cast(str[current_wchar++]); + + // UTF-16 to UTF-8 encoding + if (wc < 0x80) + { + utf8_bytes[0] = wc; + utf8_bytes_filled = 1; + } + else if (wc <= 0x7FF) + { + utf8_bytes[0] = 0xC0 | ((wc >> 6)); + utf8_bytes[1] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 2; + } + else if (0xD800 > wc or wc >= 0xE000) + { + utf8_bytes[0] = 0xE0 | ((wc >> 12)); + utf8_bytes[1] = 0x80 | ((wc >> 6) & 0x3F); + utf8_bytes[2] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 3; + } + else + { + if (current_wchar < str.size()) + { + const int wc2 = static_cast(str[current_wchar++]); + const int charcode = 0x10000 + (((wc & 0x3FF) << 10) | (wc2 & 0x3FF)); + utf8_bytes[0] = 0xf0 | (charcode >> 18); + utf8_bytes[1] = 0x80 | ((charcode >> 12) & 0x3F); + utf8_bytes[2] = 0x80 | ((charcode >> 6) & 0x3F); + utf8_bytes[3] = 0x80 | (charcode & 0x3F); + utf8_bytes_filled = 4; + } + else + { + // unknown character + ++current_wchar; + utf8_bytes[0] = wc; + utf8_bytes_filled = 1; + } + } + } + } + + void fill_buffer_utf32() + { + utf8_bytes_index = 0; + + if (current_wchar == str.size()) + { + utf8_bytes[0] = std::char_traits::eof(); + utf8_bytes_filled = 1; + } + else + { + // get the current character + const int wc = static_cast(str[current_wchar++]); + + // UTF-32 to UTF-8 encoding + if (wc < 0x80) + { + utf8_bytes[0] = wc; + utf8_bytes_filled = 1; + } + else if (wc <= 0x7FF) + { + utf8_bytes[0] = 0xC0 | ((wc >> 6) & 0x1F); + utf8_bytes[1] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 2; + } + else if (wc <= 0xFFFF) + { + utf8_bytes[0] = 0xE0 | ((wc >> 12) & 0x0F); + utf8_bytes[1] = 0x80 | ((wc >> 6) & 0x3F); + utf8_bytes[2] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 3; + } + else if (wc <= 0x10FFFF) + { + utf8_bytes[0] = 0xF0 | ((wc >> 18 ) & 0x07); + utf8_bytes[1] = 0x80 | ((wc >> 12) & 0x3F); + utf8_bytes[2] = 0x80 | ((wc >> 6) & 0x3F); + utf8_bytes[3] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 4; + } + else + { + // unknown character + utf8_bytes[0] = wc; + utf8_bytes_filled = 1; + } + } + } + + private: + /// the wstring to process + const WideStringType& str; + + /// index of the current wchar in str + std::size_t current_wchar = 0; + + /// a buffer for UTF-8 bytes + std::array::int_type, 4> utf8_bytes = {{0, 0, 0, 0}}; + + /// index to the utf8_codes array for the next valid byte + std::size_t utf8_bytes_index = 0; + /// number of valid bytes in the utf8_codes array + std::size_t utf8_bytes_filled = 0; +}; + +class input_adapter +{ + public: + // native support + + /// input adapter for input stream + input_adapter(std::istream& i) + : ia(std::make_shared(i)) {} + + /// input adapter for input stream + input_adapter(std::istream&& i) + : ia(std::make_shared(i)) {} + + input_adapter(const std::wstring& ws) + : ia(std::make_shared>(ws)) {} + + input_adapter(const std::u16string& ws) + : ia(std::make_shared>(ws)) {} + + input_adapter(const std::u32string& ws) + : ia(std::make_shared>(ws)) {} + + /// input adapter for buffer + template::value and + std::is_integral::type>::value and + sizeof(typename std::remove_pointer::type) == 1, + int>::type = 0> + input_adapter(CharT b, std::size_t l) + : ia(std::make_shared(reinterpret_cast(b), l)) {} + + // derived support + + /// input adapter for string literal + template::value and + std::is_integral::type>::value and + sizeof(typename std::remove_pointer::type) == 1, + int>::type = 0> + input_adapter(CharT b) + : input_adapter(reinterpret_cast(b), + std::strlen(reinterpret_cast(b))) {} + + /// input adapter for iterator range with contiguous storage + template::iterator_category, std::random_access_iterator_tag>::value, + int>::type = 0> + input_adapter(IteratorType first, IteratorType last) + { + // assertion to check that the iterator range is indeed contiguous, + // see http://stackoverflow.com/a/35008842/266378 for more discussion + assert(std::accumulate( + first, last, std::pair(true, 0), + [&first](std::pair res, decltype(*first) val) + { + res.first &= (val == *(std::next(std::addressof(*first), res.second++))); + return res; + }).first); + + // assertion to check that each element is 1 byte long + static_assert( + sizeof(typename std::iterator_traits::value_type) == 1, + "each element in the iterator range must have the size of 1 byte"); + + const auto len = static_cast(std::distance(first, last)); + if (JSON_LIKELY(len > 0)) + { + // there is at least one element: use the address of first + ia = std::make_shared(reinterpret_cast(&(*first)), len); + } + else + { + // the address of first cannot be used: use nullptr + ia = std::make_shared(nullptr, len); + } + } + + /// input adapter for array + template + input_adapter(T (&array)[N]) + : input_adapter(std::begin(array), std::end(array)) {} + + /// input adapter for contiguous container + template::value and + std::is_base_of()))>::iterator_category>::value, + int>::type = 0> + input_adapter(const ContiguousContainer& c) + : input_adapter(std::begin(c), std::end(c)) {} + + operator input_adapter_t() + { + return ia; + } + + private: + /// the actual adapter + input_adapter_t ia = nullptr; +}; +} +} + +// #include + + +#include // localeconv +#include // size_t +#include // strtof, strtod, strtold, strtoll, strtoull +#include // initializer_list +#include // hex, uppercase +#include // setw, setfill +#include // stringstream +#include // char_traits, string +#include // vector + +// #include + +// #include + + +namespace nlohmann +{ +namespace detail +{ +/////////// +// lexer // +/////////// + +/*! +@brief lexical analysis + +This class organizes the lexical analysis during JSON deserialization. +*/ +template +class lexer +{ + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; + + public: + /// token types for the parser + enum class token_type + { + uninitialized, ///< indicating the scanner is uninitialized + literal_true, ///< the `true` literal + literal_false, ///< the `false` literal + literal_null, ///< the `null` literal + value_string, ///< a string -- use get_string() for actual value + value_unsigned, ///< an unsigned integer -- use get_number_unsigned() for actual value + value_integer, ///< a signed integer -- use get_number_integer() for actual value + value_float, ///< an floating point number -- use get_number_float() for actual value + begin_array, ///< the character for array begin `[` + begin_object, ///< the character for object begin `{` + end_array, ///< the character for array end `]` + end_object, ///< the character for object end `}` + name_separator, ///< the name separator `:` + value_separator, ///< the value separator `,` + parse_error, ///< indicating a parse error + end_of_input, ///< indicating the end of the input buffer + literal_or_value ///< a literal or the begin of a value (only for diagnostics) + }; + + /// return name of values of type token_type (only used for errors) + static const char* token_type_name(const token_type t) noexcept + { + switch (t) + { + case token_type::uninitialized: + return ""; + case token_type::literal_true: + return "true literal"; + case token_type::literal_false: + return "false literal"; + case token_type::literal_null: + return "null literal"; + case token_type::value_string: + return "string literal"; + case lexer::token_type::value_unsigned: + case lexer::token_type::value_integer: + case lexer::token_type::value_float: + return "number literal"; + case token_type::begin_array: + return "'['"; + case token_type::begin_object: + return "'{'"; + case token_type::end_array: + return "']'"; + case token_type::end_object: + return "'}'"; + case token_type::name_separator: + return "':'"; + case token_type::value_separator: + return "','"; + case token_type::parse_error: + return ""; + case token_type::end_of_input: + return "end of input"; + case token_type::literal_or_value: + return "'[', '{', or a literal"; + default: // catch non-enum values + return "unknown token"; // LCOV_EXCL_LINE + } + } + + explicit lexer(detail::input_adapter_t&& adapter) + : ia(std::move(adapter)), decimal_point_char(get_decimal_point()) {} + + // delete because of pointer members + lexer(const lexer&) = delete; + lexer& operator=(lexer&) = delete; + + private: + ///////////////////// + // locales + ///////////////////// + + /// return the locale-dependent decimal point + static char get_decimal_point() noexcept + { + const auto loc = localeconv(); + assert(loc != nullptr); + return (loc->decimal_point == nullptr) ? '.' : *(loc->decimal_point); + } + + ///////////////////// + // scan functions + ///////////////////// + + /*! + @brief get codepoint from 4 hex characters following `\u` + + For input "\u c1 c2 c3 c4" the codepoint is: + (c1 * 0x1000) + (c2 * 0x0100) + (c3 * 0x0010) + c4 + = (c1 << 12) + (c2 << 8) + (c3 << 4) + (c4 << 0) + + Furthermore, the possible characters '0'..'9', 'A'..'F', and 'a'..'f' + must be converted to the integers 0x0..0x9, 0xA..0xF, 0xA..0xF, resp. The + conversion is done by subtracting the offset (0x30, 0x37, and 0x57) + between the ASCII value of the character and the desired integer value. + + @return codepoint (0x0000..0xFFFF) or -1 in case of an error (e.g. EOF or + non-hex character) + */ + int get_codepoint() + { + // this function only makes sense after reading `\u` + assert(current == 'u'); + int codepoint = 0; + + const auto factors = { 12, 8, 4, 0 }; + for (const auto factor : factors) + { + get(); + + if (current >= '0' and current <= '9') + { + codepoint += ((current - 0x30) << factor); + } + else if (current >= 'A' and current <= 'F') + { + codepoint += ((current - 0x37) << factor); + } + else if (current >= 'a' and current <= 'f') + { + codepoint += ((current - 0x57) << factor); + } + else + { + return -1; + } + } + + assert(0x0000 <= codepoint and codepoint <= 0xFFFF); + return codepoint; + } + + /*! + @brief check if the next byte(s) are inside a given range + + Adds the current byte and, for each passed range, reads a new byte and + checks if it is inside the range. If a violation was detected, set up an + error message and return false. Otherwise, return true. + + @param[in] ranges list of integers; interpreted as list of pairs of + inclusive lower and upper bound, respectively + + @pre The passed list @a ranges must have 2, 4, or 6 elements; that is, + 1, 2, or 3 pairs. This precondition is enforced by an assertion. + + @return true if and only if no range violation was detected + */ + bool next_byte_in_range(std::initializer_list ranges) + { + assert(ranges.size() == 2 or ranges.size() == 4 or ranges.size() == 6); + add(current); + + for (auto range = ranges.begin(); range != ranges.end(); ++range) + { + get(); + if (JSON_LIKELY(*range <= current and current <= *(++range))) + { + add(current); + } + else + { + error_message = "invalid string: ill-formed UTF-8 byte"; + return false; + } + } + + return true; + } + + /*! + @brief scan a string literal + + This function scans a string according to Sect. 7 of RFC 7159. While + scanning, bytes are escaped and copied into buffer token_buffer. Then the + function returns successfully, token_buffer is *not* null-terminated (as it + may contain \0 bytes), and token_buffer.size() is the number of bytes in the + string. + + @return token_type::value_string if string could be successfully scanned, + token_type::parse_error otherwise + + @note In case of errors, variable error_message contains a textual + description. + */ + token_type scan_string() + { + // reset token_buffer (ignore opening quote) + reset(); + + // we entered the function by reading an open quote + assert(current == '\"'); + + while (true) + { + // get next character + switch (get()) + { + // end of file while parsing string + case std::char_traits::eof(): + { + error_message = "invalid string: missing closing quote"; + return token_type::parse_error; + } + + // closing quote + case '\"': + { + return token_type::value_string; + } + + // escapes + case '\\': + { + switch (get()) + { + // quotation mark + case '\"': + add('\"'); + break; + // reverse solidus + case '\\': + add('\\'); + break; + // solidus + case '/': + add('/'); + break; + // backspace + case 'b': + add('\b'); + break; + // form feed + case 'f': + add('\f'); + break; + // line feed + case 'n': + add('\n'); + break; + // carriage return + case 'r': + add('\r'); + break; + // tab + case 't': + add('\t'); + break; + + // unicode escapes + case 'u': + { + const int codepoint1 = get_codepoint(); + int codepoint = codepoint1; // start with codepoint1 + + if (JSON_UNLIKELY(codepoint1 == -1)) + { + error_message = "invalid string: '\\u' must be followed by 4 hex digits"; + return token_type::parse_error; + } + + // check if code point is a high surrogate + if (0xD800 <= codepoint1 and codepoint1 <= 0xDBFF) + { + // expect next \uxxxx entry + if (JSON_LIKELY(get() == '\\' and get() == 'u')) + { + const int codepoint2 = get_codepoint(); + + if (JSON_UNLIKELY(codepoint2 == -1)) + { + error_message = "invalid string: '\\u' must be followed by 4 hex digits"; + return token_type::parse_error; + } + + // check if codepoint2 is a low surrogate + if (JSON_LIKELY(0xDC00 <= codepoint2 and codepoint2 <= 0xDFFF)) + { + // overwrite codepoint + codepoint = + // high surrogate occupies the most significant 22 bits + (codepoint1 << 10) + // low surrogate occupies the least significant 15 bits + + codepoint2 + // there is still the 0xD800, 0xDC00 and 0x10000 noise + // in the result so we have to subtract with: + // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00 + - 0x35FDC00; + } + else + { + error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF"; + return token_type::parse_error; + } + } + else + { + error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF"; + return token_type::parse_error; + } + } + else + { + if (JSON_UNLIKELY(0xDC00 <= codepoint1 and codepoint1 <= 0xDFFF)) + { + error_message = "invalid string: surrogate U+DC00..U+DFFF must follow U+D800..U+DBFF"; + return token_type::parse_error; + } + } + + // result of the above calculation yields a proper codepoint + assert(0x00 <= codepoint and codepoint <= 0x10FFFF); + + // translate codepoint into bytes + if (codepoint < 0x80) + { + // 1-byte characters: 0xxxxxxx (ASCII) + add(codepoint); + } + else if (codepoint <= 0x7FF) + { + // 2-byte characters: 110xxxxx 10xxxxxx + add(0xC0 | (codepoint >> 6)); + add(0x80 | (codepoint & 0x3F)); + } + else if (codepoint <= 0xFFFF) + { + // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx + add(0xE0 | (codepoint >> 12)); + add(0x80 | ((codepoint >> 6) & 0x3F)); + add(0x80 | (codepoint & 0x3F)); + } + else + { + // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx + add(0xF0 | (codepoint >> 18)); + add(0x80 | ((codepoint >> 12) & 0x3F)); + add(0x80 | ((codepoint >> 6) & 0x3F)); + add(0x80 | (codepoint & 0x3F)); + } + + break; + } + + // other characters after escape + default: + error_message = "invalid string: forbidden character after backslash"; + return token_type::parse_error; + } + + break; + } + + // invalid control characters + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0A: + case 0x0B: + case 0x0C: + case 0x0D: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + case 0x18: + case 0x19: + case 0x1A: + case 0x1B: + case 0x1C: + case 0x1D: + case 0x1E: + case 0x1F: + { + error_message = "invalid string: control character must be escaped"; + return token_type::parse_error; + } + + // U+0020..U+007F (except U+0022 (quote) and U+005C (backspace)) + case 0x20: + case 0x21: + case 0x23: + case 0x24: + case 0x25: + case 0x26: + case 0x27: + case 0x28: + case 0x29: + case 0x2A: + case 0x2B: + case 0x2C: + case 0x2D: + case 0x2E: + case 0x2F: + case 0x30: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + case 0x38: + case 0x39: + case 0x3A: + case 0x3B: + case 0x3C: + case 0x3D: + case 0x3E: + case 0x3F: + case 0x40: + case 0x41: + case 0x42: + case 0x43: + case 0x44: + case 0x45: + case 0x46: + case 0x47: + case 0x48: + case 0x49: + case 0x4A: + case 0x4B: + case 0x4C: + case 0x4D: + case 0x4E: + case 0x4F: + case 0x50: + case 0x51: + case 0x52: + case 0x53: + case 0x54: + case 0x55: + case 0x56: + case 0x57: + case 0x58: + case 0x59: + case 0x5A: + case 0x5B: + case 0x5D: + case 0x5E: + case 0x5F: + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + case 0x78: + case 0x79: + case 0x7A: + case 0x7B: + case 0x7C: + case 0x7D: + case 0x7E: + case 0x7F: + { + add(current); + break; + } + + // U+0080..U+07FF: bytes C2..DF 80..BF + case 0xC2: + case 0xC3: + case 0xC4: + case 0xC5: + case 0xC6: + case 0xC7: + case 0xC8: + case 0xC9: + case 0xCA: + case 0xCB: + case 0xCC: + case 0xCD: + case 0xCE: + case 0xCF: + case 0xD0: + case 0xD1: + case 0xD2: + case 0xD3: + case 0xD4: + case 0xD5: + case 0xD6: + case 0xD7: + case 0xD8: + case 0xD9: + case 0xDA: + case 0xDB: + case 0xDC: + case 0xDD: + case 0xDE: + case 0xDF: + { + if (JSON_UNLIKELY(not next_byte_in_range({0x80, 0xBF}))) + { + return token_type::parse_error; + } + break; + } + + // U+0800..U+0FFF: bytes E0 A0..BF 80..BF + case 0xE0: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0xA0, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } + + // U+1000..U+CFFF: bytes E1..EC 80..BF 80..BF + // U+E000..U+FFFF: bytes EE..EF 80..BF 80..BF + case 0xE1: + case 0xE2: + case 0xE3: + case 0xE4: + case 0xE5: + case 0xE6: + case 0xE7: + case 0xE8: + case 0xE9: + case 0xEA: + case 0xEB: + case 0xEC: + case 0xEE: + case 0xEF: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } + + // U+D000..U+D7FF: bytes ED 80..9F 80..BF + case 0xED: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0x9F, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } + + // U+10000..U+3FFFF F0 90..BF 80..BF 80..BF + case 0xF0: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x90, 0xBF, 0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } + + // U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF + case 0xF1: + case 0xF2: + case 0xF3: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } + + // U+100000..U+10FFFF F4 80..8F 80..BF 80..BF + case 0xF4: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0x8F, 0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } + + // remaining bytes (80..C1 and F5..FF) are ill-formed + default: + { + error_message = "invalid string: ill-formed UTF-8 byte"; + return token_type::parse_error; + } + } + } + } + + static void strtof(float& f, const char* str, char** endptr) noexcept + { + f = std::strtof(str, endptr); + } + + static void strtof(double& f, const char* str, char** endptr) noexcept + { + f = std::strtod(str, endptr); + } + + static void strtof(long double& f, const char* str, char** endptr) noexcept + { + f = std::strtold(str, endptr); + } + + /*! + @brief scan a number literal + + This function scans a string according to Sect. 6 of RFC 7159. + + The function is realized with a deterministic finite state machine derived + from the grammar described in RFC 7159. Starting in state "init", the + input is read and used to determined the next state. Only state "done" + accepts the number. State "error" is a trap state to model errors. In the + table below, "anything" means any character but the ones listed before. + + state | 0 | 1-9 | e E | + | - | . | anything + ---------|----------|----------|----------|---------|---------|----------|----------- + init | zero | any1 | [error] | [error] | minus | [error] | [error] + minus | zero | any1 | [error] | [error] | [error] | [error] | [error] + zero | done | done | exponent | done | done | decimal1 | done + any1 | any1 | any1 | exponent | done | done | decimal1 | done + decimal1 | decimal2 | [error] | [error] | [error] | [error] | [error] | [error] + decimal2 | decimal2 | decimal2 | exponent | done | done | done | done + exponent | any2 | any2 | [error] | sign | sign | [error] | [error] + sign | any2 | any2 | [error] | [error] | [error] | [error] | [error] + any2 | any2 | any2 | done | done | done | done | done + + The state machine is realized with one label per state (prefixed with + "scan_number_") and `goto` statements between them. The state machine + contains cycles, but any cycle can be left when EOF is read. Therefore, + the function is guaranteed to terminate. + + During scanning, the read bytes are stored in token_buffer. This string is + then converted to a signed integer, an unsigned integer, or a + floating-point number. + + @return token_type::value_unsigned, token_type::value_integer, or + token_type::value_float if number could be successfully scanned, + token_type::parse_error otherwise + + @note The scanner is independent of the current locale. Internally, the + locale's decimal point is used instead of `.` to work with the + locale-dependent converters. + */ + token_type scan_number() + { + // reset token_buffer to store the number's bytes + reset(); + + // the type of the parsed number; initially set to unsigned; will be + // changed if minus sign, decimal point or exponent is read + token_type number_type = token_type::value_unsigned; + + // state (init): we just found out we need to scan a number + switch (current) + { + case '-': + { + add(current); + goto scan_number_minus; + } + + case '0': + { + add(current); + goto scan_number_zero; + } + + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any1; + } + + default: + { + // all other characters are rejected outside scan_number() + assert(false); // LCOV_EXCL_LINE + } + } + +scan_number_minus: + // state: we just parsed a leading minus sign + number_type = token_type::value_integer; + switch (get()) + { + case '0': + { + add(current); + goto scan_number_zero; + } + + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any1; + } + + default: + { + error_message = "invalid number; expected digit after '-'"; + return token_type::parse_error; + } + } + +scan_number_zero: + // state: we just parse a zero (maybe with a leading minus sign) + switch (get()) + { + case '.': + { + add(decimal_point_char); + goto scan_number_decimal1; + } + + case 'e': + case 'E': + { + add(current); + goto scan_number_exponent; + } + + default: + goto scan_number_done; + } + +scan_number_any1: + // state: we just parsed a number 0-9 (maybe with a leading minus sign) + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any1; + } + + case '.': + { + add(decimal_point_char); + goto scan_number_decimal1; + } + + case 'e': + case 'E': + { + add(current); + goto scan_number_exponent; + } + + default: + goto scan_number_done; + } + +scan_number_decimal1: + // state: we just parsed a decimal point + number_type = token_type::value_float; + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_decimal2; + } + + default: + { + error_message = "invalid number; expected digit after '.'"; + return token_type::parse_error; + } + } + +scan_number_decimal2: + // we just parsed at least one number after a decimal point + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_decimal2; + } + + case 'e': + case 'E': + { + add(current); + goto scan_number_exponent; + } + + default: + goto scan_number_done; + } + +scan_number_exponent: + // we just parsed an exponent + number_type = token_type::value_float; + switch (get()) + { + case '+': + case '-': + { + add(current); + goto scan_number_sign; + } + + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any2; + } + + default: + { + error_message = + "invalid number; expected '+', '-', or digit after exponent"; + return token_type::parse_error; + } + } + +scan_number_sign: + // we just parsed an exponent sign + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any2; + } + + default: + { + error_message = "invalid number; expected digit after exponent sign"; + return token_type::parse_error; + } + } + +scan_number_any2: + // we just parsed a number after the exponent or exponent sign + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any2; + } + + default: + goto scan_number_done; + } + +scan_number_done: + // unget the character after the number (we only read it to know that + // we are done scanning a number) + unget(); + + char* endptr = nullptr; + errno = 0; + + // try to parse integers first and fall back to floats + if (number_type == token_type::value_unsigned) + { + const auto x = std::strtoull(token_buffer.data(), &endptr, 10); + + // we checked the number format before + assert(endptr == token_buffer.data() + token_buffer.size()); + + if (errno == 0) + { + value_unsigned = static_cast(x); + if (value_unsigned == x) + { + return token_type::value_unsigned; + } + } + } + else if (number_type == token_type::value_integer) + { + const auto x = std::strtoll(token_buffer.data(), &endptr, 10); + + // we checked the number format before + assert(endptr == token_buffer.data() + token_buffer.size()); + + if (errno == 0) + { + value_integer = static_cast(x); + if (value_integer == x) + { + return token_type::value_integer; + } + } + } + + // this code is reached if we parse a floating-point number or if an + // integer conversion above failed + strtof(value_float, token_buffer.data(), &endptr); + + // we checked the number format before + assert(endptr == token_buffer.data() + token_buffer.size()); + + return token_type::value_float; + } + + /*! + @param[in] literal_text the literal text to expect + @param[in] length the length of the passed literal text + @param[in] return_type the token type to return on success + */ + token_type scan_literal(const char* literal_text, const std::size_t length, + token_type return_type) + { + assert(current == literal_text[0]); + for (std::size_t i = 1; i < length; ++i) + { + if (JSON_UNLIKELY(get() != literal_text[i])) + { + error_message = "invalid literal"; + return token_type::parse_error; + } + } + return return_type; + } + + ///////////////////// + // input management + ///////////////////// + + /// reset token_buffer; current character is beginning of token + void reset() noexcept + { + token_buffer.clear(); + token_string.clear(); + token_string.push_back(std::char_traits::to_char_type(current)); + } + + /* + @brief get next character from the input + + This function provides the interface to the used input adapter. It does + not throw in case the input reached EOF, but returns a + `std::char_traits::eof()` in that case. Stores the scanned characters + for use in error messages. + + @return character read from the input + */ + std::char_traits::int_type get() + { + ++chars_read; + if (next_unget) + { + // just reset the next_unget variable and work with current + next_unget = false; + } + else + { + current = ia->get_character(); + } + + if (JSON_LIKELY(current != std::char_traits::eof())) + { + token_string.push_back(std::char_traits::to_char_type(current)); + } + return current; + } + + /*! + @brief unget current character (read it again on next get) + + We implement unget by setting variable next_unget to true. The input is not + changed - we just simulate ungetting by modifying chars_read and + token_string. The next call to get() will behave as if the unget character + is read again. + */ + void unget() + { + next_unget = true; + --chars_read; + if (JSON_LIKELY(current != std::char_traits::eof())) + { + assert(token_string.size() != 0); + token_string.pop_back(); + } + } + + /// add a character to token_buffer + void add(int c) + { + token_buffer.push_back(std::char_traits::to_char_type(c)); + } + + public: + ///////////////////// + // value getters + ///////////////////// + + /// return integer value + constexpr number_integer_t get_number_integer() const noexcept + { + return value_integer; + } + + /// return unsigned integer value + constexpr number_unsigned_t get_number_unsigned() const noexcept + { + return value_unsigned; + } + + /// return floating-point value + constexpr number_float_t get_number_float() const noexcept + { + return value_float; + } + + /// return current string value (implicitly resets the token; useful only once) + string_t& get_string() + { + return token_buffer; + } + + ///////////////////// + // diagnostics + ///////////////////// + + /// return position of last read token + constexpr std::size_t get_position() const noexcept + { + return chars_read; + } + + /// return the last read token (for errors only). Will never contain EOF + /// (an arbitrary value that is not a valid char value, often -1), because + /// 255 may legitimately occur. May contain NUL, which should be escaped. + std::string get_token_string() const + { + // escape control characters + std::string result; + for (const auto c : token_string) + { + if ('\x00' <= c and c <= '\x1F') + { + // escape control characters + std::stringstream ss; + ss << "(c) << ">"; + result += ss.str(); + } + else + { + // add character as is + result.push_back(c); + } + } + + return result; + } + + /// return syntax error message + constexpr const char* get_error_message() const noexcept + { + return error_message; + } + + ///////////////////// + // actual scanner + ///////////////////// + + /*! + @brief skip the UTF-8 byte order mark + @return true iff there is no BOM or the correct BOM has been skipped + */ + bool skip_bom() + { + if (get() == 0xEF) + { + if (get() == 0xBB and get() == 0xBF) + { + // we completely parsed the BOM + return true; + } + else + { + // after reading 0xEF, an unexpected character followed + return false; + } + } + else + { + // the first character is not the beginning of the BOM; unget it to + // process is later + unget(); + return true; + } + } + + token_type scan() + { + // initially, skip the BOM + if (chars_read == 0 and not skip_bom()) + { + error_message = "invalid BOM; must be 0xEF 0xBB 0xBF if given"; + return token_type::parse_error; + } + + // read next character and ignore whitespace + do + { + get(); + } + while (current == ' ' or current == '\t' or current == '\n' or current == '\r'); + + switch (current) + { + // structural characters + case '[': + return token_type::begin_array; + case ']': + return token_type::end_array; + case '{': + return token_type::begin_object; + case '}': + return token_type::end_object; + case ':': + return token_type::name_separator; + case ',': + return token_type::value_separator; + + // literals + case 't': + return scan_literal("true", 4, token_type::literal_true); + case 'f': + return scan_literal("false", 5, token_type::literal_false); + case 'n': + return scan_literal("null", 4, token_type::literal_null); + + // string + case '\"': + return scan_string(); + + // number + case '-': + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + return scan_number(); + + // end of input (the null byte is needed when parsing from + // string literals) + case '\0': + case std::char_traits::eof(): + return token_type::end_of_input; + + // error + default: + error_message = "invalid literal"; + return token_type::parse_error; + } + } + + private: + /// input adapter + detail::input_adapter_t ia = nullptr; + + /// the current character + std::char_traits::int_type current = std::char_traits::eof(); + + /// whether the next get() call should just return current + bool next_unget = false; + + /// the number of characters read + std::size_t chars_read = 0; + + /// raw input token string (for error messages) + std::vector token_string {}; + + /// buffer for variable-length tokens (numbers, strings) + string_t token_buffer {}; + + /// a description of occurred lexer errors + const char* error_message = ""; + + // number values + number_integer_t value_integer = 0; + number_unsigned_t value_unsigned = 0; + number_float_t value_float = 0; + + /// the decimal point + const char decimal_point_char = '.'; +}; +} +} + +// #include + + +#include // assert +#include // isfinite +#include // uint8_t +#include // function +#include // string +#include // move + +// #include + +// #include + +// #include + +// #include + + +#include +#include +#include + +// #include + +// #include + + +namespace nlohmann +{ + +/*! +@brief SAX interface +*/ +template +struct json_sax +{ + /// type for (signed) integers + using number_integer_t = typename BasicJsonType::number_integer_t; + /// type for unsigned integers + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + /// type for floating-point numbers + using number_float_t = typename BasicJsonType::number_float_t; + /// type for strings + using string_t = typename BasicJsonType::string_t; + + /// constant to indicate that no size limit is given for array or object + static constexpr auto no_limit = std::size_t(-1); + + /*! + @brief a null value was read + @return whether parsing should proceed + */ + virtual bool null() = 0; + + /*! + @brief a boolean value was read + @param[in] val boolean value + @return whether parsing should proceed + */ + virtual bool boolean(bool val) = 0; + + /*! + @brief an integer number was read + @param[in] val integer value + @return whether parsing should proceed + */ + virtual bool number_integer(number_integer_t val) = 0; + + /*! + @brief an unsigned integer number was read + @param[in] val unsigned integer value + @return whether parsing should proceed + */ + virtual bool number_unsigned(number_unsigned_t val) = 0; + + /*! + @brief an floating-point number was read + @param[in] val floating-point value + @param[in] s raw token value + @return whether parsing should proceed + */ + virtual bool number_float(number_float_t val, const string_t& s) = 0; + + /*! + @brief a string was read + @param[in] val string value + @return whether parsing should proceed + */ + virtual bool string(string_t& val) = 0; + + /*! + @brief the beginning of an object was read + @param[in] elements number of object elements or no_limit if unknown + @return whether parsing should proceed + @note binary formats may report the number of elements + */ + virtual bool start_object(std::size_t elements = no_limit) = 0; + + /*! + @brief an object key was read + @param[in] val object key + @return whether parsing should proceed + */ + virtual bool key(string_t& val) = 0; + + /*! + @brief the end of an object was read + @return whether parsing should proceed + */ + virtual bool end_object() = 0; + + /*! + @brief the beginning of an array was read + @param[in] elements number of array elements or no_limit if unknown + @return whether parsing should proceed + @note binary formats may report the number of elements + */ + virtual bool start_array(std::size_t elements = no_limit) = 0; + + /*! + @brief the end of an array was read + @return whether parsing should proceed + */ + virtual bool end_array() = 0; + + /*! + @brief a parse error occurred + @param[in] position the position in the input where the error occurs + @param[in] last_token the last read token + @param[in] error_msg a detailed error message + @return whether parsing should proceed (must return false) + */ + virtual bool parse_error(std::size_t position, + const std::string& last_token, + const detail::exception& ex) = 0; + + virtual ~json_sax() = default; +}; + + +namespace detail +{ +/*! +@brief SAX implementation to create a JSON value from SAX events + +This class implements the @ref json_sax interface and processes the SAX events +to create a JSON value which makes it basically a DOM parser. The structure or +hierarchy of the JSON value is managed by the stack `ref_stack` which contains +a pointer to the respective array or object for each recursion depth. + +After successful parsing, the value that is passed by reference to the +constructor contains the parsed value. + +@tparam BasicJsonType the JSON type +*/ +template +class json_sax_dom_parser : public json_sax +{ + public: + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; + + /*! + @param[in, out] r reference to a JSON value that is manipulated while + parsing + @param[in] allow_exceptions_ whether parse errors yield exceptions + */ + json_sax_dom_parser(BasicJsonType& r, const bool allow_exceptions_ = true) + : root(r), allow_exceptions(allow_exceptions_) + {} + + bool null() override + { + handle_value(nullptr); + return true; + } + + bool boolean(bool val) override + { + handle_value(val); + return true; + } + + bool number_integer(number_integer_t val) override + { + handle_value(val); + return true; + } + + bool number_unsigned(number_unsigned_t val) override + { + handle_value(val); + return true; + } + + bool number_float(number_float_t val, const string_t&) override + { + handle_value(val); + return true; + } + + bool string(string_t& val) override + { + handle_value(val); + return true; + } + + bool start_object(std::size_t len) override + { + ref_stack.push_back(handle_value(BasicJsonType::value_t::object)); + + if (JSON_UNLIKELY(len != json_sax::no_limit and len > ref_stack.back()->max_size())) + { + JSON_THROW(out_of_range::create(408, + "excessive object size: " + std::to_string(len))); + } + + return true; + } + + bool key(string_t& val) override + { + // add null at given key and store the reference for later + object_element = &(ref_stack.back()->m_value.object->operator[](val)); + return true; + } + + bool end_object() override + { + ref_stack.pop_back(); + return true; + } + + bool start_array(std::size_t len) override + { + ref_stack.push_back(handle_value(BasicJsonType::value_t::array)); + + if (JSON_UNLIKELY(len != json_sax::no_limit and len > ref_stack.back()->max_size())) + { + JSON_THROW(out_of_range::create(408, + "excessive array size: " + std::to_string(len))); + } + + return true; + } + + bool end_array() override + { + ref_stack.pop_back(); + return true; + } + + bool parse_error(std::size_t, const std::string&, + const detail::exception& ex) override + { + errored = true; + if (allow_exceptions) + { + // determine the proper exception type from the id + switch ((ex.id / 100) % 100) + { + case 1: + JSON_THROW(*reinterpret_cast(&ex)); + case 2: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + case 3: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + case 4: + JSON_THROW(*reinterpret_cast(&ex)); + case 5: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + default: + assert(false); // LCOV_EXCL_LINE + } + } + return false; + } + + constexpr bool is_errored() const + { + return errored; + } + + private: + /*! + @invariant If the ref stack is empty, then the passed value will be the new + root. + @invariant If the ref stack contains a value, then it is an array or an + object to which we can add elements + */ + template + BasicJsonType* handle_value(Value&& v) + { + if (ref_stack.empty()) + { + root = BasicJsonType(std::forward(v)); + return &root; + } + else + { + assert(ref_stack.back()->is_array() or ref_stack.back()->is_object()); + if (ref_stack.back()->is_array()) + { + ref_stack.back()->m_value.array->emplace_back(std::forward(v)); + return &(ref_stack.back()->m_value.array->back()); + } + else + { + assert(object_element); + *object_element = BasicJsonType(std::forward(v)); + return object_element; + } + } + } + + /// the parsed JSON value + BasicJsonType& root; + /// stack to model hierarchy of values + std::vector ref_stack; + /// helper to hold the reference for the next object element + BasicJsonType* object_element = nullptr; + /// whether a syntax error occurred + bool errored = false; + /// whether to throw exceptions in case of errors + const bool allow_exceptions = true; +}; + +template +class json_sax_dom_callback_parser : public json_sax +{ + public: + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; + using parser_callback_t = typename BasicJsonType::parser_callback_t; + using parse_event_t = typename BasicJsonType::parse_event_t; + + json_sax_dom_callback_parser(BasicJsonType& r, + const parser_callback_t cb, + const bool allow_exceptions_ = true) + : root(r), callback(cb), allow_exceptions(allow_exceptions_) + { + keep_stack.push_back(true); + } + + bool null() override + { + handle_value(nullptr); + return true; + } + + bool boolean(bool val) override + { + handle_value(val); + return true; + } + + bool number_integer(number_integer_t val) override + { + handle_value(val); + return true; + } + + bool number_unsigned(number_unsigned_t val) override + { + handle_value(val); + return true; + } + + bool number_float(number_float_t val, const string_t&) override + { + handle_value(val); + return true; + } + + bool string(string_t& val) override + { + handle_value(val); + return true; + } + + bool start_object(std::size_t len) override + { + // check callback for object start + const bool keep = callback(static_cast(ref_stack.size()), parse_event_t::object_start, discarded); + keep_stack.push_back(keep); + + auto val = handle_value(BasicJsonType::value_t::object, true); + ref_stack.push_back(val.second); + + // check object limit + if (ref_stack.back()) + { + if (JSON_UNLIKELY(len != json_sax::no_limit and len > ref_stack.back()->max_size())) + { + JSON_THROW(out_of_range::create(408, + "excessive object size: " + std::to_string(len))); + } + } + + return true; + } + + bool key(string_t& val) override + { + BasicJsonType k = BasicJsonType(val); + + // check callback for key + const bool keep = callback(static_cast(ref_stack.size()), parse_event_t::key, k); + key_keep_stack.push_back(keep); + + // add discarded value at given key and store the reference for later + if (keep and ref_stack.back()) + { + object_element = &(ref_stack.back()->m_value.object->operator[](val) = discarded); + } + + return true; + } + + bool end_object() override + { + bool keep = true; + if (ref_stack.back()) + { + keep = callback(static_cast(ref_stack.size()) - 1, parse_event_t::object_end, *ref_stack.back()); + if (not keep) + { + // discard object + *ref_stack.back() = discarded; + } + } + + assert(not ref_stack.empty()); + assert(not keep_stack.empty()); + ref_stack.pop_back(); + keep_stack.pop_back(); + + if (not ref_stack.empty() and ref_stack.back()) + { + // remove discarded value + if (ref_stack.back()->is_object()) + { + for (auto it = ref_stack.back()->begin(); it != ref_stack.back()->end(); ++it) + { + if (it->is_discarded()) + { + ref_stack.back()->erase(it); + break; + } + } + } + } + + return true; + } + + bool start_array(std::size_t len) override + { + const bool keep = callback(static_cast(ref_stack.size()), parse_event_t::array_start, discarded); + keep_stack.push_back(keep); + + auto val = handle_value(BasicJsonType::value_t::array, true); + ref_stack.push_back(val.second); + + // check array limit + if (ref_stack.back()) + { + if (JSON_UNLIKELY(len != json_sax::no_limit and len > ref_stack.back()->max_size())) + { + JSON_THROW(out_of_range::create(408, + "excessive array size: " + std::to_string(len))); + } + } + + return true; + } + + bool end_array() override + { + bool keep = true; + + if (ref_stack.back()) + { + keep = callback(static_cast(ref_stack.size()) - 1, parse_event_t::array_end, *ref_stack.back()); + if (not keep) + { + // discard array + *ref_stack.back() = discarded; + } + } + + assert(not ref_stack.empty()); + assert(not keep_stack.empty()); + ref_stack.pop_back(); + keep_stack.pop_back(); + + // remove discarded value + if (not keep and not ref_stack.empty()) + { + if (ref_stack.back()->is_array()) + { + ref_stack.back()->m_value.array->pop_back(); + } + } + + return true; + } + + bool parse_error(std::size_t, const std::string&, + const detail::exception& ex) override + { + errored = true; + if (allow_exceptions) + { + // determine the proper exception type from the id + switch ((ex.id / 100) % 100) + { + case 1: + JSON_THROW(*reinterpret_cast(&ex)); + case 2: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + case 3: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + case 4: + JSON_THROW(*reinterpret_cast(&ex)); + case 5: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + default: + assert(false); // LCOV_EXCL_LINE + } + } + return false; + } + + constexpr bool is_errored() const + { + return errored; + } + + private: + /*! + @param[in] v value to add to the JSON value we build during parsing + @param[in] skip_callback whether we should skip calling the callback + function; this is required after start_array() and + start_object() SAX events, because otherwise we would call the + callback function with an empty array or object, respectively. + + @invariant If the ref stack is empty, then the passed value will be the new + root. + @invariant If the ref stack contains a value, then it is an array or an + object to which we can add elements + + @return pair of boolean (whether value should be kept) and pointer (to the + passed value in the ref_stack hierarchy; nullptr if not kept) + */ + template + std::pair handle_value(Value&& v, const bool skip_callback = false) + { + assert(not keep_stack.empty()); + + // do not handle this value if we know it would be added to a discarded + // container + if (not keep_stack.back()) + { + return {false, nullptr}; + } + + // create value + auto value = BasicJsonType(std::forward(v)); + + // check callback + const bool keep = skip_callback or callback(static_cast(ref_stack.size()), parse_event_t::value, value); + + // do not handle this value if we just learnt it shall be discarded + if (not keep) + { + return {false, nullptr}; + } + + if (ref_stack.empty()) + { + root = std::move(value); + return {true, &root}; + } + else + { + assert(ref_stack.back()->is_array() or ref_stack.back()->is_object()); + if (ref_stack.back()->is_array()) + { + ref_stack.back()->m_value.array->push_back(std::move(value)); + return {true, &(ref_stack.back()->m_value.array->back())}; + } + else + { + // check if we should store an element for the current key + assert(not key_keep_stack.empty()); + const bool store_element = key_keep_stack.back(); + key_keep_stack.pop_back(); + + if (not store_element) + { + return {false, nullptr}; + } + + assert(object_element); + *object_element = std::move(value); + return {true, object_element}; + } + } + } + + /// the parsed JSON value + BasicJsonType& root; + /// stack to model hierarchy of values + std::vector ref_stack; + /// stack to manage which values to keep + std::vector keep_stack; + /// stack to manage which object keys to keep + std::vector key_keep_stack; + /// helper to hold the reference for the next object element + BasicJsonType* object_element = nullptr; + /// whether a syntax error occurred + bool errored = false; + /// callback function + const parser_callback_t callback = nullptr; + /// whether to throw exceptions in case of errors + const bool allow_exceptions = true; + /// a discarded value for the callback + BasicJsonType discarded = BasicJsonType::value_t::discarded; +}; + +template +class json_sax_acceptor : public json_sax +{ + public: + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; + + bool null() override + { + return true; + } + + bool boolean(bool) override + { + return true; + } + + bool number_integer(number_integer_t) override + { + return true; + } + + bool number_unsigned(number_unsigned_t) override + { + return true; + } + + bool number_float(number_float_t, const string_t&) override + { + return true; + } + + bool string(string_t&) override + { + return true; + } + + bool start_object(std::size_t) override + { + return true; + } + + bool key(string_t&) override + { + return true; + } + + bool end_object() override + { + return true; + } + + bool start_array(std::size_t) override + { + return true; + } + + bool end_array() override + { + return true; + } + + bool parse_error(std::size_t, const std::string&, const detail::exception&) override + { + return false; + } +}; +} + +} + +// #include + +// #include + + +namespace nlohmann +{ +namespace detail +{ +//////////// +// parser // +//////////// + +/*! +@brief syntax analysis + +This class implements a recursive decent parser. +*/ +template +class parser +{ + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; + using lexer_t = lexer; + using token_type = typename lexer_t::token_type; + + public: + enum class parse_event_t : uint8_t + { + /// the parser read `{` and started to process a JSON object + object_start, + /// the parser read `}` and finished processing a JSON object + object_end, + /// the parser read `[` and started to process a JSON array + array_start, + /// the parser read `]` and finished processing a JSON array + array_end, + /// the parser read a key of a value in an object + key, + /// the parser finished reading a JSON value + value + }; + + using json_sax_t = json_sax; + + using parser_callback_t = + std::function; + + /// a parser reading from an input adapter + explicit parser(detail::input_adapter_t&& adapter, + const parser_callback_t cb = nullptr, + const bool allow_exceptions_ = true) + : callback(cb), m_lexer(std::move(adapter)), allow_exceptions(allow_exceptions_) + { + // read first token + get_token(); + } + + /*! + @brief public parser interface + + @param[in] strict whether to expect the last token to be EOF + @param[in,out] result parsed JSON value + + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails + */ + void parse(const bool strict, BasicJsonType& result) + { + if (callback) + { + json_sax_dom_callback_parser sdp(result, callback, allow_exceptions); + sax_parse_internal(&sdp); + result.assert_invariant(); + + // in strict mode, input must be completely read + if (strict and (get_token() != token_type::end_of_input)) + { + sdp.parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_of_input))); + } + + // in case of an error, return discarded value + if (sdp.is_errored()) + { + result = value_t::discarded; + return; + } + + // set top-level value to null if it was discarded by the callback + // function + if (result.is_discarded()) + { + result = nullptr; + } + } + else + { + json_sax_dom_parser sdp(result, allow_exceptions); + sax_parse_internal(&sdp); + result.assert_invariant(); + + // in strict mode, input must be completely read + if (strict and (get_token() != token_type::end_of_input)) + { + sdp.parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_of_input))); + } + + // in case of an error, return discarded value + if (sdp.is_errored()) + { + result = value_t::discarded; + return; + } + } + } + + /*! + @brief public accept interface + + @param[in] strict whether to expect the last token to be EOF + @return whether the input is a proper JSON text + */ + bool accept(const bool strict = true) + { + json_sax_acceptor sax_acceptor; + return sax_parse(&sax_acceptor, strict); + } + + bool sax_parse(json_sax_t* sax, const bool strict = true) + { + const bool result = sax_parse_internal(sax); + + // strict mode: next byte must be EOF + if (result and strict and (get_token() != token_type::end_of_input)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_of_input))); + } + + return result; + } + + private: + bool sax_parse_internal(json_sax_t* sax) + { + // stack to remember the hieararchy of structured values we are parsing + // true = array; false = object + std::vector states; + // value to avoid a goto (see comment where set to true) + bool skip_to_state_evaluation = false; + + while (true) + { + if (not skip_to_state_evaluation) + { + // invariant: get_token() was called before each iteration + switch (last_token) + { + case token_type::begin_object: + { + if (JSON_UNLIKELY(not sax->start_object())) + { + return false; + } + + // closing } -> we are done + if (get_token() == token_type::end_object) + { + if (JSON_UNLIKELY(not sax->end_object())) + { + return false; + } + break; + } + + // parse key + if (JSON_UNLIKELY(last_token != token_type::value_string)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::value_string))); + } + else + { + if (JSON_UNLIKELY(not sax->key(m_lexer.get_string()))) + { + return false; + } + } + + // parse separator (:) + if (JSON_UNLIKELY(get_token() != token_type::name_separator)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::name_separator))); + } + + // remember we are now inside an object + states.push_back(false); + + // parse values + get_token(); + continue; + } + + case token_type::begin_array: + { + if (JSON_UNLIKELY(not sax->start_array())) + { + return false; + } + + // closing ] -> we are done + if (get_token() == token_type::end_array) + { + if (JSON_UNLIKELY(not sax->end_array())) + { + return false; + } + break; + } + + // remember we are now inside an array + states.push_back(true); + + // parse values (no need to call get_token) + continue; + } + + case token_type::value_float: + { + const auto res = m_lexer.get_number_float(); + + if (JSON_UNLIKELY(not std::isfinite(res))) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + out_of_range::create(406, "number overflow parsing '" + m_lexer.get_token_string() + "'")); + } + else + { + if (JSON_UNLIKELY(not sax->number_float(res, m_lexer.get_string()))) + { + return false; + } + break; + } + } + + case token_type::literal_false: + { + if (JSON_UNLIKELY(not sax->boolean(false))) + { + return false; + } + break; + } + + case token_type::literal_null: + { + if (JSON_UNLIKELY(not sax->null())) + { + return false; + } + break; + } + + case token_type::literal_true: + { + if (JSON_UNLIKELY(not sax->boolean(true))) + { + return false; + } + break; + } + + case token_type::value_integer: + { + if (JSON_UNLIKELY(not sax->number_integer(m_lexer.get_number_integer()))) + { + return false; + } + break; + } + + case token_type::value_string: + { + if (JSON_UNLIKELY(not sax->string(m_lexer.get_string()))) + { + return false; + } + break; + } + + case token_type::value_unsigned: + { + if (JSON_UNLIKELY(not sax->number_unsigned(m_lexer.get_number_unsigned()))) + { + return false; + } + break; + } + + case token_type::parse_error: + { + // using "uninitialized" to avoid "expected" message + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::uninitialized))); + } + + default: // the last token was unexpected + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::literal_or_value))); + } + } + } + else + { + skip_to_state_evaluation = false; + } + + // we reached this line after we successfully parsed a value + if (states.empty()) + { + // empty stack: we reached the end of the hieararchy: done + return true; + } + else + { + if (states.back()) // array + { + // comma -> next value + if (get_token() == token_type::value_separator) + { + // parse a new value + get_token(); + continue; + } + + // closing ] + if (JSON_LIKELY(last_token == token_type::end_array)) + { + if (JSON_UNLIKELY(not sax->end_array())) + { + return false; + } + + // We are done with this array. Before we can parse a + // new value, we need to evaluate the new state first. + // By setting skip_to_state_evaluation to false, we + // are effectively jumping to the beginning of this if. + assert(not states.empty()); + states.pop_back(); + skip_to_state_evaluation = true; + continue; + } + else + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_array))); + } + } + else // object + { + // comma -> next value + if (get_token() == token_type::value_separator) + { + // parse key + if (JSON_UNLIKELY(get_token() != token_type::value_string)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::value_string))); + } + else + { + if (JSON_UNLIKELY(not sax->key(m_lexer.get_string()))) + { + return false; + } + } + + // parse separator (:) + if (JSON_UNLIKELY(get_token() != token_type::name_separator)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::name_separator))); + } + + // parse values + get_token(); + continue; + } + + // closing } + if (JSON_LIKELY(last_token == token_type::end_object)) + { + if (JSON_UNLIKELY(not sax->end_object())) + { + return false; + } + + // We are done with this object. Before we can parse a + // new value, we need to evaluate the new state first. + // By setting skip_to_state_evaluation to false, we + // are effectively jumping to the beginning of this if. + assert(not states.empty()); + states.pop_back(); + skip_to_state_evaluation = true; + continue; + } + else + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_object))); + } + } + } + } + } + + /// get next token from lexer + token_type get_token() + { + return (last_token = m_lexer.scan()); + } + + std::string exception_message(const token_type expected) + { + std::string error_msg = "syntax error - "; + if (last_token == token_type::parse_error) + { + error_msg += std::string(m_lexer.get_error_message()) + "; last read: '" + + m_lexer.get_token_string() + "'"; + } + else + { + error_msg += "unexpected " + std::string(lexer_t::token_type_name(last_token)); + } + + if (expected != token_type::uninitialized) + { + error_msg += "; expected " + std::string(lexer_t::token_type_name(expected)); + } + + return error_msg; + } + + private: + /// callback function + const parser_callback_t callback = nullptr; + /// the type of the last read token + token_type last_token = token_type::uninitialized; + /// the lexer + lexer_t m_lexer; + /// whether to throw exceptions in case of errors + const bool allow_exceptions = true; +}; +} +} + +// #include + + +#include // ptrdiff_t +#include // numeric_limits + +namespace nlohmann +{ +namespace detail +{ +/* +@brief an iterator for primitive JSON types + +This class models an iterator for primitive JSON types (boolean, number, +string). It's only purpose is to allow the iterator/const_iterator classes +to "iterate" over primitive values. Internally, the iterator is modeled by +a `difference_type` variable. Value begin_value (`0`) models the begin, +end_value (`1`) models past the end. +*/ +class primitive_iterator_t +{ + private: + using difference_type = std::ptrdiff_t; + static constexpr difference_type begin_value = 0; + static constexpr difference_type end_value = begin_value + 1; + + /// iterator as signed integer type + difference_type m_it = (std::numeric_limits::min)(); + + public: + constexpr difference_type get_value() const noexcept + { + return m_it; + } + + /// set iterator to a defined beginning + void set_begin() noexcept + { + m_it = begin_value; + } + + /// set iterator to a defined past the end + void set_end() noexcept + { + m_it = end_value; + } + + /// return whether the iterator can be dereferenced + constexpr bool is_begin() const noexcept + { + return m_it == begin_value; + } + + /// return whether the iterator is at end + constexpr bool is_end() const noexcept + { + return m_it == end_value; + } + + friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + { + return lhs.m_it == rhs.m_it; + } + + friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + { + return lhs.m_it < rhs.m_it; + } + + primitive_iterator_t operator+(difference_type n) noexcept + { + auto result = *this; + result += n; + return result; + } + + friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + { + return lhs.m_it - rhs.m_it; + } + + primitive_iterator_t& operator++() noexcept + { + ++m_it; + return *this; + } + + primitive_iterator_t const operator++(int) noexcept + { + auto result = *this; + m_it++; + return result; + } + + primitive_iterator_t& operator--() noexcept + { + --m_it; + return *this; + } + + primitive_iterator_t const operator--(int) noexcept + { + auto result = *this; + m_it--; + return result; + } + + primitive_iterator_t& operator+=(difference_type n) noexcept + { + m_it += n; + return *this; + } + + primitive_iterator_t& operator-=(difference_type n) noexcept + { + m_it -= n; + return *this; + } +}; +} +} + +// #include + + +// #include + + +namespace nlohmann +{ +namespace detail +{ +/*! +@brief an iterator value + +@note This structure could easily be a union, but MSVC currently does not allow +unions members with complex constructors, see https://github.com/nlohmann/json/pull/105. +*/ +template struct internal_iterator +{ + /// iterator for JSON objects + typename BasicJsonType::object_t::iterator object_iterator {}; + /// iterator for JSON arrays + typename BasicJsonType::array_t::iterator array_iterator {}; + /// generic iterator for all other types + primitive_iterator_t primitive_iterator {}; +}; +} +} + +// #include + + +#include // not +#include // iterator, random_access_iterator_tag, bidirectional_iterator_tag, advance, next +#include // conditional, is_const, remove_const + +// #include + +// #include + +// #include + +// #include + +// #include + +// #include + + +namespace nlohmann +{ +namespace detail +{ +// forward declare, to be able to friend it later on +template class iteration_proxy; + +/*! +@brief a template for a bidirectional iterator for the @ref basic_json class + +This class implements a both iterators (iterator and const_iterator) for the +@ref basic_json class. + +@note An iterator is called *initialized* when a pointer to a JSON value has + been set (e.g., by a constructor or a copy assignment). If the iterator is + default-constructed, it is *uninitialized* and most methods are undefined. + **The library uses assertions to detect calls on uninitialized iterators.** + +@requirement The class satisfies the following concept requirements: +- +[BidirectionalIterator](http://en.cppreference.com/w/cpp/concept/BidirectionalIterator): + The iterator that can be moved can be moved in both directions (i.e. + incremented and decremented). + +@since version 1.0.0, simplified in version 2.0.9, change to bidirectional + iterators in version 3.0.0 (see https://github.com/nlohmann/json/issues/593) +*/ +template +class iter_impl +{ + /// allow basic_json to access private members + friend iter_impl::value, typename std::remove_const::type, const BasicJsonType>::type>; + friend BasicJsonType; + friend iteration_proxy; + + using object_t = typename BasicJsonType::object_t; + using array_t = typename BasicJsonType::array_t; + // make sure BasicJsonType is basic_json or const basic_json + static_assert(is_basic_json::type>::value, + "iter_impl only accepts (const) basic_json"); + + public: + + /// The std::iterator class template (used as a base class to provide typedefs) is deprecated in C++17. + /// The C++ Standard has never required user-defined iterators to derive from std::iterator. + /// A user-defined iterator should provide publicly accessible typedefs named + /// iterator_category, value_type, difference_type, pointer, and reference. + /// Note that value_type is required to be non-const, even for constant iterators. + using iterator_category = std::bidirectional_iterator_tag; + + /// the type of the values when the iterator is dereferenced + using value_type = typename BasicJsonType::value_type; + /// a type to represent differences between iterators + using difference_type = typename BasicJsonType::difference_type; + /// defines a pointer to the type iterated over (value_type) + using pointer = typename std::conditional::value, + typename BasicJsonType::const_pointer, + typename BasicJsonType::pointer>::type; + /// defines a reference to the type iterated over (value_type) + using reference = + typename std::conditional::value, + typename BasicJsonType::const_reference, + typename BasicJsonType::reference>::type; + + /// default constructor + iter_impl() = default; + + /*! + @brief constructor for a given JSON instance + @param[in] object pointer to a JSON object for this iterator + @pre object != nullptr + @post The iterator is initialized; i.e. `m_object != nullptr`. + */ + explicit iter_impl(pointer object) noexcept : m_object(object) + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + { + m_it.object_iterator = typename object_t::iterator(); + break; + } + + case value_t::array: + { + m_it.array_iterator = typename array_t::iterator(); + break; + } + + default: + { + m_it.primitive_iterator = primitive_iterator_t(); + break; + } + } + } + + /*! + @note The conventional copy constructor and copy assignment are implicitly + defined. Combined with the following converting constructor and + assignment, they support: (1) copy from iterator to iterator, (2) + copy from const iterator to const iterator, and (3) conversion from + iterator to const iterator. However conversion from const iterator + to iterator is not defined. + */ + + /*! + @brief converting constructor + @param[in] other non-const iterator to copy from + @note It is not checked whether @a other is initialized. + */ + iter_impl(const iter_impl::type>& other) noexcept + : m_object(other.m_object), m_it(other.m_it) {} + + /*! + @brief converting assignment + @param[in,out] other non-const iterator to copy from + @return const/non-const iterator + @note It is not checked whether @a other is initialized. + */ + iter_impl& operator=(const iter_impl::type>& other) noexcept + { + m_object = other.m_object; + m_it = other.m_it; + return *this; + } + + private: + /*! + @brief set the iterator to the first value + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + void set_begin() noexcept + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + { + m_it.object_iterator = m_object->m_value.object->begin(); + break; + } + + case value_t::array: + { + m_it.array_iterator = m_object->m_value.array->begin(); + break; + } + + case value_t::null: + { + // set to end so begin()==end() is true: null is empty + m_it.primitive_iterator.set_end(); + break; + } + + default: + { + m_it.primitive_iterator.set_begin(); + break; + } + } + } + + /*! + @brief set the iterator past the last value + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + void set_end() noexcept + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + { + m_it.object_iterator = m_object->m_value.object->end(); + break; + } + + case value_t::array: + { + m_it.array_iterator = m_object->m_value.array->end(); + break; + } + + default: + { + m_it.primitive_iterator.set_end(); + break; + } + } + } + + public: + /*! + @brief return a reference to the value pointed to by the iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + reference operator*() const + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + { + assert(m_it.object_iterator != m_object->m_value.object->end()); + return m_it.object_iterator->second; + } + + case value_t::array: + { + assert(m_it.array_iterator != m_object->m_value.array->end()); + return *m_it.array_iterator; + } + + case value_t::null: + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + + default: + { + if (JSON_LIKELY(m_it.primitive_iterator.is_begin())) + { + return *m_object; + } + + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + } + } + } + + /*! + @brief dereference the iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + pointer operator->() const + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + { + assert(m_it.object_iterator != m_object->m_value.object->end()); + return &(m_it.object_iterator->second); + } + + case value_t::array: + { + assert(m_it.array_iterator != m_object->m_value.array->end()); + return &*m_it.array_iterator; + } + + default: + { + if (JSON_LIKELY(m_it.primitive_iterator.is_begin())) + { + return m_object; + } + + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + } + } + } + + /*! + @brief post-increment (it++) + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl const operator++(int) + { + auto result = *this; + ++(*this); + return result; + } + + /*! + @brief pre-increment (++it) + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator++() + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + { + std::advance(m_it.object_iterator, 1); + break; + } + + case value_t::array: + { + std::advance(m_it.array_iterator, 1); + break; + } + + default: + { + ++m_it.primitive_iterator; + break; + } + } + + return *this; + } + + /*! + @brief post-decrement (it--) + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl const operator--(int) + { + auto result = *this; + --(*this); + return result; + } + + /*! + @brief pre-decrement (--it) + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator--() + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + { + std::advance(m_it.object_iterator, -1); + break; + } + + case value_t::array: + { + std::advance(m_it.array_iterator, -1); + break; + } + + default: + { + --m_it.primitive_iterator; + break; + } + } + + return *this; } /*! - @brief convert any value type to a JSON value + @brief comparison: equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator==(const iter_impl& other) const + { + // if objects are not the same, the comparison is undefined + if (JSON_UNLIKELY(m_object != other.m_object)) + { + JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); + } - This function is usually called by the constructors of the @ref basic_json - class. + assert(m_object != nullptr); - @param[in,out] j JSON value to write to - @param[in] val value to read from + switch (m_object->m_type) + { + case value_t::object: + return (m_it.object_iterator == other.m_it.object_iterator); + + case value_t::array: + return (m_it.array_iterator == other.m_it.array_iterator); + + default: + return (m_it.primitive_iterator == other.m_it.primitive_iterator); + } + } + + /*! + @brief comparison: not equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - template - static void to_json(BasicJsonType& j, ValueType&& val) noexcept( - noexcept(::nlohmann::to_json(j, std::forward(val)))) + bool operator!=(const iter_impl& other) const { - ::nlohmann::to_json(j, std::forward(val)); + return not operator==(other); } -}; + /*! + @brief comparison: smaller + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator<(const iter_impl& other) const + { + // if objects are not the same, the comparison is undefined + if (JSON_UNLIKELY(m_object != other.m_object)) + { + JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); + } -/*! -@brief a class to store JSON values + assert(m_object != nullptr); -@tparam ObjectType type for JSON objects (`std::map` by default; will be used -in @ref object_t) -@tparam ArrayType type for JSON arrays (`std::vector` by default; will be used -in @ref array_t) -@tparam StringType type for JSON strings and object keys (`std::string` by -default; will be used in @ref string_t) -@tparam BooleanType type for JSON booleans (`bool` by default; will be used -in @ref boolean_t) -@tparam NumberIntegerType type for JSON integer numbers (`int64_t` by -default; will be used in @ref number_integer_t) -@tparam NumberUnsignedType type for JSON unsigned integer numbers (@c -`uint64_t` by default; will be used in @ref number_unsigned_t) -@tparam NumberFloatType type for JSON floating-point numbers (`double` by -default; will be used in @ref number_float_t) -@tparam AllocatorType type of the allocator to use (`std::allocator` by -default) -@tparam JSONSerializer the serializer to resolve internal calls to `to_json()` -and `from_json()` (@ref adl_serializer by default) + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(213, "cannot compare order of object iterators")); -@requirement The class satisfies the following concept requirements: -- Basic - - [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible): - JSON values can be default constructed. The result will be a JSON null - value. - - [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible): - A JSON value can be constructed from an rvalue argument. - - [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible): - A JSON value can be copy-constructed from an lvalue expression. - - [MoveAssignable](http://en.cppreference.com/w/cpp/concept/MoveAssignable): - A JSON value van be assigned from an rvalue argument. - - [CopyAssignable](http://en.cppreference.com/w/cpp/concept/CopyAssignable): - A JSON value can be copy-assigned from an lvalue expression. - - [Destructible](http://en.cppreference.com/w/cpp/concept/Destructible): - JSON values can be destructed. -- Layout - - [StandardLayoutType](http://en.cppreference.com/w/cpp/concept/StandardLayoutType): - JSON values have - [standard layout](http://en.cppreference.com/w/cpp/language/data_members#Standard_layout): - All non-static data members are private and standard layout types, the - class has no virtual functions or (virtual) base classes. -- Library-wide - - [EqualityComparable](http://en.cppreference.com/w/cpp/concept/EqualityComparable): - JSON values can be compared with `==`, see @ref - operator==(const_reference,const_reference). - - [LessThanComparable](http://en.cppreference.com/w/cpp/concept/LessThanComparable): - JSON values can be compared with `<`, see @ref - operator<(const_reference,const_reference). - - [Swappable](http://en.cppreference.com/w/cpp/concept/Swappable): - Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of - other compatible types, using unqualified function call @ref swap(). - - [NullablePointer](http://en.cppreference.com/w/cpp/concept/NullablePointer): - JSON values can be compared against `std::nullptr_t` objects which are used - to model the `null` value. -- Container - - [Container](http://en.cppreference.com/w/cpp/concept/Container): - JSON values can be used like STL containers and provide iterator access. - - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer); - JSON values can be used like STL containers and provide reverse iterator - access. + case value_t::array: + return (m_it.array_iterator < other.m_it.array_iterator); -@invariant The member variables @a m_value and @a m_type have the following -relationship: -- If `m_type == value_t::object`, then `m_value.object != nullptr`. -- If `m_type == value_t::array`, then `m_value.array != nullptr`. -- If `m_type == value_t::string`, then `m_value.string != nullptr`. -The invariants are checked by member function assert_invariant(). + default: + return (m_it.primitive_iterator < other.m_it.primitive_iterator); + } + } -@internal -@note ObjectType trick from http://stackoverflow.com/a/9860911 -@endinternal + /*! + @brief comparison: less than or equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator<=(const iter_impl& other) const + { + return not other.operator < (*this); + } -@see [RFC 7159: The JavaScript Object Notation (JSON) Data Interchange -Format](http://rfc7159.net/rfc7159) + /*! + @brief comparison: greater than + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator>(const iter_impl& other) const + { + return not operator<=(other); + } -@since version 1.0.0 + /*! + @brief comparison: greater than or equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator>=(const iter_impl& other) const + { + return not operator<(other); + } -@nosubgrouping -*/ -template < - template class ObjectType = std::map, - template class ArrayType = std::vector, - class StringType = std::string, - class BooleanType = bool, - class NumberIntegerType = std::int64_t, - class NumberUnsignedType = std::uint64_t, - class NumberFloatType = double, - template class AllocatorType = std::allocator, - template class JSONSerializer = adl_serializer - > -class basic_json + /*! + @brief add to iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator+=(difference_type i) + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); + + case value_t::array: + { + std::advance(m_it.array_iterator, i); + break; + } + + default: + { + m_it.primitive_iterator += i; + break; + } + } + + return *this; + } + + /*! + @brief subtract from iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator-=(difference_type i) + { + return operator+=(-i); + } + + /*! + @brief add to iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl operator+(difference_type i) const + { + auto result = *this; + result += i; + return result; + } + + /*! + @brief addition of distance and iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + friend iter_impl operator+(difference_type i, const iter_impl& it) + { + auto result = it; + result += i; + return result; + } + + /*! + @brief subtract from iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl operator-(difference_type i) const + { + auto result = *this; + result -= i; + return result; + } + + /*! + @brief return difference + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + difference_type operator-(const iter_impl& other) const + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); + + case value_t::array: + return m_it.array_iterator - other.m_it.array_iterator; + + default: + return m_it.primitive_iterator - other.m_it.primitive_iterator; + } + } + + /*! + @brief access to successor + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + reference operator[](difference_type n) const + { + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(208, "cannot use operator[] for object iterators")); + + case value_t::array: + return *std::next(m_it.array_iterator, n); + + case value_t::null: + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + + default: + { + if (JSON_LIKELY(m_it.primitive_iterator.get_value() == -n)) + { + return *m_object; + } + + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + } + } + } + + /*! + @brief return the key of an object iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + const typename object_t::key_type& key() const + { + assert(m_object != nullptr); + + if (JSON_LIKELY(m_object->is_object())) + { + return m_it.object_iterator->first; + } + + JSON_THROW(invalid_iterator::create(207, "cannot use key() for non-object iterators")); + } + + /*! + @brief return the value of an iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + reference value() const + { + return operator*(); + } + + private: + /// associated JSON instance + pointer m_object = nullptr; + /// the actual iterator of the associated instance + internal_iterator::type> m_it; +}; +} +} + +// #include + + +#include // size_t +#include // string, to_string + +// #include + + +namespace nlohmann +{ +namespace detail +{ +/// proxy class for the items() function +template class iteration_proxy { private: - template friend struct detail::external_constructor; - /// workaround type for MSVC - using basic_json_t = basic_json; + /// helper class for iteration + class iteration_proxy_internal + { + private: + /// the iterator + IteratorType anchor; + /// an index for arrays (used to create key names) + std::size_t array_index = 0; + /// last stringified array index + mutable std::size_t array_index_last = 0; + /// a string representation of the array index + mutable std::string array_index_str = "0"; + /// an empty string (to return a reference for primitive values) + const std::string empty_str = ""; + + public: + explicit iteration_proxy_internal(IteratorType it) noexcept : anchor(it) {} + + /// dereference operator (needed for range-based for) + iteration_proxy_internal& operator*() + { + return *this; + } + + /// increment operator (needed for range-based for) + iteration_proxy_internal& operator++() + { + ++anchor; + ++array_index; + + return *this; + } + + /// inequality operator (needed for range-based for) + bool operator!=(const iteration_proxy_internal& o) const noexcept + { + return anchor != o.anchor; + } + + /// return key of the iterator + const std::string& key() const + { + assert(anchor.m_object != nullptr); + + switch (anchor.m_object->type()) + { + // use integer array index as key + case value_t::array: + { + if (array_index != array_index_last) + { + array_index_str = std::to_string(array_index); + array_index_last = array_index; + } + return array_index_str; + } - public: - using value_t = detail::value_t; - // forward declarations - template class iter_impl; - template class json_reverse_iterator; - class json_pointer; - template - using json_serializer = JSONSerializer; + // use key from the object + case value_t::object: + return anchor.key(); + // use an empty key for all primitive types + default: + return empty_str; + } + } - //////////////// - // exceptions // - //////////////// + /// return value of the iterator + typename IteratorType::reference value() const + { + return anchor.value(); + } + }; - /// @name exceptions - /// Classes to implement user-defined exceptions. - /// @{ + /// the container to iterate + typename IteratorType::reference container; - /// @copydoc detail::exception - using exception = detail::exception; - /// @copydoc detail::parse_error - using parse_error = detail::parse_error; - /// @copydoc detail::invalid_iterator - using invalid_iterator = detail::invalid_iterator; - /// @copydoc detail::type_error - using type_error = detail::type_error; - /// @copydoc detail::out_of_range - using out_of_range = detail::out_of_range; - /// @copydoc detail::other_error - using other_error = detail::other_error; + public: + /// construct iteration proxy from a container + explicit iteration_proxy(typename IteratorType::reference cont) noexcept + : container(cont) {} - /// @} + /// return iterator begin (needed for range-based for) + iteration_proxy_internal begin() noexcept + { + return iteration_proxy_internal(container.begin()); + } + /// return iterator end (needed for range-based for) + iteration_proxy_internal end() noexcept + { + return iteration_proxy_internal(container.end()); + } +}; +} +} - ///////////////////// - // container types // - ///////////////////// +// #include - /// @name container types - /// The canonic container types to use @ref basic_json like any other STL - /// container. - /// @{ - /// the type of elements in a basic_json container - using value_type = basic_json; +#include // ptrdiff_t +#include // reverse_iterator +#include // declval - /// the type of an element reference - using reference = value_type&; - /// the type of an element const reference - using const_reference = const value_type&; +namespace nlohmann +{ +namespace detail +{ +////////////////////// +// reverse_iterator // +////////////////////// - /// a type to represent differences between iterators - using difference_type = std::ptrdiff_t; - /// a type to represent container sizes - using size_type = std::size_t; +/*! +@brief a template for a reverse iterator class - /// the allocator type - using allocator_type = AllocatorType; +@tparam Base the base iterator type to reverse. Valid types are @ref +iterator (to create @ref reverse_iterator) and @ref const_iterator (to +create @ref const_reverse_iterator). - /// the type of an element pointer - using pointer = typename std::allocator_traits::pointer; - /// the type of an element const pointer - using const_pointer = typename std::allocator_traits::const_pointer; +@requirement The class satisfies the following concept requirements: +- +[BidirectionalIterator](http://en.cppreference.com/w/cpp/concept/BidirectionalIterator): + The iterator that can be moved can be moved in both directions (i.e. + incremented and decremented). +- [OutputIterator](http://en.cppreference.com/w/cpp/concept/OutputIterator): + It is possible to write to the pointed-to element (only if @a Base is + @ref iterator). - /// an iterator for a basic_json container - using iterator = iter_impl; - /// a const iterator for a basic_json container - using const_iterator = iter_impl; - /// a reverse iterator for a basic_json container - using reverse_iterator = json_reverse_iterator; - /// a const reverse iterator for a basic_json container - using const_reverse_iterator = json_reverse_iterator; +@since version 1.0.0 +*/ +template +class json_reverse_iterator : public std::reverse_iterator +{ + public: + using difference_type = std::ptrdiff_t; + /// shortcut to the reverse iterator adapter + using base_iterator = std::reverse_iterator; + /// the reference type for the pointed-to element + using reference = typename Base::reference; - /// @} + /// create reverse iterator from iterator + json_reverse_iterator(const typename base_iterator::iterator_type& it) noexcept + : base_iterator(it) {} + /// create reverse iterator from base class + json_reverse_iterator(const base_iterator& it) noexcept : base_iterator(it) {} - /*! - @brief returns the allocator associated with the container - */ - static allocator_type get_allocator() + /// post-increment (it++) + json_reverse_iterator const operator++(int) { - return allocator_type(); + return static_cast(base_iterator::operator++(1)); } - /*! - @brief returns version information on the library - - This function returns a JSON object with information about the library, - including the version number and information on the platform and compiler. - - @return JSON object holding version information - key | description - ----------- | --------------- - `compiler` | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version). - `copyright` | The copyright line for the library as string. - `name` | The name of the library as string. - `platform` | The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`. - `url` | The URL of the project as string. - `version` | The version of the library. It is an object with the following keys: `major`, `minor`, and `patch` as defined by [Semantic Versioning](http://semver.org), and `string` (the version string). + /// pre-increment (++it) + json_reverse_iterator& operator++() + { + return static_cast(base_iterator::operator++()); + } - @liveexample{The following code shows an example output of the `meta()` - function.,meta} + /// post-decrement (it--) + json_reverse_iterator const operator--(int) + { + return static_cast(base_iterator::operator--(1)); + } - @complexity Constant. + /// pre-decrement (--it) + json_reverse_iterator& operator--() + { + return static_cast(base_iterator::operator--()); + } - @since 2.1.0 - */ - static basic_json meta() + /// add to iterator + json_reverse_iterator& operator+=(difference_type i) { - basic_json result; + return static_cast(base_iterator::operator+=(i)); + } - result["copyright"] = "(C) 2013-2017 Niels Lohmann"; - result["name"] = "JSON for Modern C++"; - result["url"] = "https://github.com/nlohmann/json"; - result["version"] = - { - {"string", "2.1.1"}, {"major", 2}, {"minor", 1}, {"patch", 1} - }; + /// add to iterator + json_reverse_iterator operator+(difference_type i) const + { + return static_cast(base_iterator::operator+(i)); + } -#ifdef _WIN32 - result["platform"] = "win32"; -#elif defined __linux__ - result["platform"] = "linux"; -#elif defined __APPLE__ - result["platform"] = "apple"; -#elif defined __unix__ - result["platform"] = "unix"; -#else - result["platform"] = "unknown"; -#endif + /// subtract from iterator + json_reverse_iterator operator-(difference_type i) const + { + return static_cast(base_iterator::operator-(i)); + } -#if defined(__clang__) - result["compiler"] = {{"family", "clang"}, {"version", __clang_version__}}; -#elif defined(__ICC) || defined(__INTEL_COMPILER) - result["compiler"] = {{"family", "icc"}, {"version", __INTEL_COMPILER}}; -#elif defined(__GNUC__) || defined(__GNUG__) - result["compiler"] = {{"family", "gcc"}, {"version", std::to_string(__GNUC__) + "." + std::to_string(__GNUC_MINOR__) + "." + std::to_string(__GNUC_PATCHLEVEL__)}}; -#elif defined(__HP_cc) || defined(__HP_aCC) - result["compiler"] = "hp" -#elif defined(__IBMCPP__) - result["compiler"] = {{"family", "ilecpp"}, {"version", __IBMCPP__}}; -#elif defined(_MSC_VER) - result["compiler"] = {{"family", "msvc"}, {"version", _MSC_VER}}; -#elif defined(__PGI) - result["compiler"] = {{"family", "pgcpp"}, {"version", __PGI}}; -#elif defined(__SUNPRO_CC) - result["compiler"] = {{"family", "sunpro"}, {"version", __SUNPRO_CC}}; -#else - result["compiler"] = {{"family", "unknown"}, {"version", "unknown"}}; -#endif + /// return difference + difference_type operator-(const json_reverse_iterator& other) const + { + return base_iterator(*this) - base_iterator(other); + } -#ifdef __cplusplus - result["compiler"]["c++"] = std::to_string(__cplusplus); -#else - result["compiler"]["c++"] = "unknown"; -#endif - return result; + /// access to successor + reference operator[](difference_type n) const + { + return *(this->operator+(n)); } + /// return the key of an object iterator + auto key() const -> decltype(std::declval().key()) + { + auto it = --this->base(); + return it.key(); + } - /////////////////////////// - // JSON value data types // - /////////////////////////// + /// return the value of an iterator + reference value() const + { + auto it = --this->base(); + return it.operator * (); + } +}; +} +} - /// @name JSON value data types - /// The data types to store a JSON value. These types are derived from - /// the template arguments passed to class @ref basic_json. - /// @{ +// #include - /*! - @brief a type for an object - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows: - > An object is an unordered collection of zero or more name/value pairs, - > where a name is a string and a value is a string, number, boolean, null, - > object, or array. +#include // copy +#include // size_t +#include // streamsize +#include // back_inserter +#include // shared_ptr, make_shared +#include // basic_ostream +#include // basic_string +#include // vector - To store objects in C++, a type is defined by the template parameters - described below. +namespace nlohmann +{ +namespace detail +{ +/// abstract output adapter interface +template struct output_adapter_protocol +{ + virtual void write_character(CharType c) = 0; + virtual void write_characters(const CharType* s, std::size_t length) = 0; + virtual ~output_adapter_protocol() = default; +}; - @tparam ObjectType the container to store objects (e.g., `std::map` or - `std::unordered_map`) - @tparam StringType the type of the keys or names (e.g., `std::string`). - The comparison function `std::less` is used to order elements - inside the container. - @tparam AllocatorType the allocator to use for objects (e.g., - `std::allocator`) +/// a type to simplify interfaces +template +using output_adapter_t = std::shared_ptr>; - #### Default type +/// output adapter for byte vectors +template +class output_vector_adapter : public output_adapter_protocol +{ + public: + explicit output_vector_adapter(std::vector& vec) : v(vec) {} - With the default values for @a ObjectType (`std::map`), @a StringType - (`std::string`), and @a AllocatorType (`std::allocator`), the default - value for @a object_t is: + void write_character(CharType c) override + { + v.push_back(c); + } - @code {.cpp} - std::map< - std::string, // key_type - basic_json, // value_type - std::less, // key_compare - std::allocator> // allocator_type - > - @endcode + void write_characters(const CharType* s, std::size_t length) override + { + std::copy(s, s + length, std::back_inserter(v)); + } - #### Behavior + private: + std::vector& v; +}; - The choice of @a object_t influences the behavior of the JSON class. With - the default type, objects have the following behavior: +/// output adapter for output streams +template +class output_stream_adapter : public output_adapter_protocol +{ + public: + explicit output_stream_adapter(std::basic_ostream& s) : stream(s) {} - - When all names are unique, objects will be interoperable in the sense - that all software implementations receiving that object will agree on - the name-value mappings. - - When the names within an object are not unique, later stored name/value - pairs overwrite previously stored name/value pairs, leaving the used - names unique. For instance, `{"key": 1}` and `{"key": 2, "key": 1}` will - be treated as equal and both stored as `{"key": 1}`. - - Internally, name/value pairs are stored in lexicographical order of the - names. Objects will also be serialized (see @ref dump) in this order. - For instance, `{"b": 1, "a": 2}` and `{"a": 2, "b": 1}` will be stored - and serialized as `{"a": 2, "b": 1}`. - - When comparing objects, the order of the name/value pairs is irrelevant. - This makes objects interoperable in the sense that they will not be - affected by these differences. For instance, `{"b": 1, "a": 2}` and - `{"a": 2, "b": 1}` will be treated as equal. + void write_character(CharType c) override + { + stream.put(c); + } - #### Limits + void write_characters(const CharType* s, std::size_t length) override + { + stream.write(s, static_cast(length)); + } - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the maximum depth of nesting. + private: + std::basic_ostream& stream; +}; - In this class, the object's limit of nesting is not constraint explicitly. - However, a maximum depth of nesting may be introduced by the compiler or - runtime environment. A theoretical limit can be queried by calling the - @ref max_size function of a JSON object. +/// output adapter for basic_string +template> +class output_string_adapter : public output_adapter_protocol +{ + public: + explicit output_string_adapter(StringType& s) : str(s) {} - #### Storage + void write_character(CharType c) override + { + str.push_back(c); + } - Objects are stored as pointers in a @ref basic_json type. That is, for any - access to object values, a pointer of type `object_t*` must be - dereferenced. + void write_characters(const CharType* s, std::size_t length) override + { + str.append(s, length); + } - @sa @ref array_t -- type for an array value + private: + StringType& str; +}; - @since version 1.0.0 +template> +class output_adapter +{ + public: + output_adapter(std::vector& vec) + : oa(std::make_shared>(vec)) {} - @note The order name/value pairs are added to the object is *not* - preserved by the library. Therefore, iterating an object may return - name/value pairs in a different order than they were originally stored. In - fact, keys will be traversed in alphabetical order as `std::map` with - `std::less` is used by default. Please note this behavior conforms to [RFC - 7159](http://rfc7159.net/rfc7159), because any order implements the - specified "unordered" nature of JSON objects. - */ - using object_t = ObjectType, - AllocatorType>>; + output_adapter(std::basic_ostream& s) + : oa(std::make_shared>(s)) {} - /*! - @brief a type for an array + output_adapter(StringType& s) + : oa(std::make_shared>(s)) {} - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows: - > An array is an ordered sequence of zero or more values. + operator output_adapter_t() + { + return oa; + } - To store objects in C++, a type is defined by the template parameters - explained below. + private: + output_adapter_t oa = nullptr; +}; +} +} - @tparam ArrayType container type to store arrays (e.g., `std::vector` or - `std::list`) - @tparam AllocatorType allocator to use for arrays (e.g., `std::allocator`) +// #include - #### Default type - With the default values for @a ArrayType (`std::vector`) and @a - AllocatorType (`std::allocator`), the default value for @a array_t is: +#include // generate_n +#include // array +#include // assert +#include // ldexp +#include // size_t +#include // uint8_t, uint16_t, uint32_t, uint64_t +#include // memcpy +#include // setw, setfill +#include // hex +#include // back_inserter +#include // numeric_limits +#include // stringstream +#include // char_traits, string +#include // make_pair, move - @code {.cpp} - std::vector< - basic_json, // value_type - std::allocator // allocator_type - > - @endcode +// #include - #### Limits +// #include - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the maximum depth of nesting. +// #include - In this class, the array's limit of nesting is not constraint explicitly. - However, a maximum depth of nesting may be introduced by the compiler or - runtime environment. A theoretical limit can be queried by calling the - @ref max_size function of a JSON array. +// #include - #### Storage +// #include - Arrays are stored as pointers in a @ref basic_json type. That is, for any - access to array values, a pointer of type `array_t*` must be dereferenced. - @sa @ref object_t -- type for an object value +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// binary reader // +/////////////////// - @since version 1.0.0 - */ - using array_t = ArrayType>; +/*! +@brief deserialization of CBOR, MessagePack, and UBJSON values +*/ +template +class binary_reader +{ + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using string_t = typename BasicJsonType::string_t; + using json_sax_t = json_sax; + public: /*! - @brief a type for a string - - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows: - > A string is a sequence of zero or more Unicode characters. + @brief create a binary reader - To store objects in C++, a type is defined by the template parameter - described below. Unicode values are split by the JSON class into - byte-sized characters during deserialization. + @param[in] adapter input adapter to read from + */ + explicit binary_reader(input_adapter_t adapter) : ia(std::move(adapter)) + { + assert(ia); + } - @tparam StringType the container to store strings (e.g., `std::string`). - Note this container is used for keys/names in objects, see @ref object_t. + /*! + @param[in] format the binary format to parse + @param[in] sax_ a SAX event processor + @param[in] strict whether to expect the input to be consumed completed - #### Default type + @return + */ + bool sax_parse(const input_format_t format, + json_sax_t* sax_, + const bool strict = true) + { + sax = sax_; + bool result; - With the default values for @a StringType (`std::string`), the default - value for @a string_t is: + switch (format) + { + case input_format_t::cbor: + result = parse_cbor_internal(); + break; - @code {.cpp} - std::string - @endcode + case input_format_t::msgpack: + result = parse_msgpack_internal(); + break; - #### Encoding + case input_format_t::ubjson: + result = parse_ubjson_internal(); + break; - Strings are stored in UTF-8 encoding. Therefore, functions like - `std::string::size()` or `std::string::length()` return the number of - bytes in the string rather than the number of characters or glyphs. + default: + assert(false); // LCOV_EXCL_LINE + } - #### String comparison + // strict mode: next byte must be EOF + if (result and strict) + { + if (format == input_format_t::ubjson) + { + get_ignore_noop(); + } + else + { + get(); + } - [RFC 7159](http://rfc7159.net/rfc7159) states: - > Software implementations are typically required to test names of object - > members for equality. Implementations that transform the textual - > representation into sequences of Unicode code units and then perform the - > comparison numerically, code unit by code unit, are interoperable in the - > sense that implementations will agree in all cases on equality or - > inequality of two strings. For example, implementations that compare - > strings with escaped characters unconverted may incorrectly find that - > `"a\\b"` and `"a\u005Cb"` are not equal. + if (JSON_UNLIKELY(current != std::char_traits::eof())) + { + return sax->parse_error(chars_read, get_token_string(), parse_error::create(110, chars_read, "expected end of input")); + } + } - This implementation is interoperable as it does compare strings code unit - by code unit. + return result; + } - #### Storage + /*! + @brief determine system byte order - String values are stored as pointers in a @ref basic_json type. That is, - for any access to string values, a pointer of type `string_t*` must be - dereferenced. + @return true if and only if system's byte order is little endian - @since version 1.0.0 + @note from http://stackoverflow.com/a/1001328/266378 */ - using string_t = StringType; + static constexpr bool little_endianess(int num = 1) noexcept + { + return (*reinterpret_cast(&num) == 1); + } + private: /*! - @brief a type for a boolean + @param[in] get_char whether a new character should be retrieved from the + input (true, default) or whether the last read + character should be considered instead - [RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a - type which differentiates the two literals `true` and `false`. + @return whether a valid CBOR value was passed to the SAX parser + */ + bool parse_cbor_internal(const bool get_char = true) + { + switch (get_char ? get() : current) + { + // EOF + case std::char_traits::eof(): + return unexpect_eof(); + + // Integer 0x00..0x17 (0..23) + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0A: + case 0x0B: + case 0x0C: + case 0x0D: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + return sax->number_unsigned(static_cast(current)); + + case 0x18: // Unsigned integer (one-byte uint8_t follows) + { + uint8_t number; + return get_number(number) and sax->number_unsigned(number); + } - To store objects in C++, a type is defined by the template parameter @a - BooleanType which chooses the type to use. + case 0x19: // Unsigned integer (two-byte uint16_t follows) + { + uint16_t number; + return get_number(number) and sax->number_unsigned(number); + } - #### Default type + case 0x1A: // Unsigned integer (four-byte uint32_t follows) + { + uint32_t number; + return get_number(number) and sax->number_unsigned(number); + } - With the default values for @a BooleanType (`bool`), the default value for - @a boolean_t is: + case 0x1B: // Unsigned integer (eight-byte uint64_t follows) + { + uint64_t number; + return get_number(number) and sax->number_unsigned(number); + } - @code {.cpp} - bool - @endcode + // Negative integer -1-0x00..-1-0x17 (-1..-24) + case 0x20: + case 0x21: + case 0x22: + case 0x23: + case 0x24: + case 0x25: + case 0x26: + case 0x27: + case 0x28: + case 0x29: + case 0x2A: + case 0x2B: + case 0x2C: + case 0x2D: + case 0x2E: + case 0x2F: + case 0x30: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + return sax->number_integer(static_cast(0x20 - 1 - current)); + + case 0x38: // Negative integer (one-byte uint8_t follows) + { + uint8_t number; + return get_number(number) and sax->number_integer(static_cast(-1) - number); + } - #### Storage + case 0x39: // Negative integer -1-n (two-byte uint16_t follows) + { + uint16_t number; + return get_number(number) and sax->number_integer(static_cast(-1) - number); + } - Boolean values are stored directly inside a @ref basic_json type. + case 0x3A: // Negative integer -1-n (four-byte uint32_t follows) + { + uint32_t number; + return get_number(number) and sax->number_integer(static_cast(-1) - number); + } - @since version 1.0.0 - */ - using boolean_t = BooleanType; + case 0x3B: // Negative integer -1-n (eight-byte uint64_t follows) + { + uint64_t number; + return get_number(number) and sax->number_integer(static_cast(-1) + - static_cast(number)); + } - /*! - @brief a type for a number (integer) + // UTF-8 string (0x00..0x17 bytes follow) + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + case 0x78: // UTF-8 string (one-byte uint8_t for n follows) + case 0x79: // UTF-8 string (two-byte uint16_t for n follow) + case 0x7A: // UTF-8 string (four-byte uint32_t for n follow) + case 0x7B: // UTF-8 string (eight-byte uint64_t for n follow) + case 0x7F: // UTF-8 string (indefinite length) + { + string_t s; + return get_cbor_string(s) and sax->string(s); + } - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. + // array (0x00..0x17 data items follow) + case 0x80: + case 0x81: + case 0x82: + case 0x83: + case 0x84: + case 0x85: + case 0x86: + case 0x87: + case 0x88: + case 0x89: + case 0x8A: + case 0x8B: + case 0x8C: + case 0x8D: + case 0x8E: + case 0x8F: + case 0x90: + case 0x91: + case 0x92: + case 0x93: + case 0x94: + case 0x95: + case 0x96: + case 0x97: + return get_cbor_array(static_cast(current & 0x1F)); + + case 0x98: // array (one-byte uint8_t for n follows) + { + uint8_t len; + return get_number(len) and get_cbor_array(static_cast(len)); + } - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. + case 0x99: // array (two-byte uint16_t for n follow) + { + uint16_t len; + return get_number(len) and get_cbor_array(static_cast(len)); + } - To store integer numbers in C++, a type is defined by the template - parameter @a NumberIntegerType which chooses the type to use. + case 0x9A: // array (four-byte uint32_t for n follow) + { + uint32_t len; + return get_number(len) and get_cbor_array(static_cast(len)); + } - #### Default type + case 0x9B: // array (eight-byte uint64_t for n follow) + { + uint64_t len; + return get_number(len) and get_cbor_array(static_cast(len)); + } - With the default values for @a NumberIntegerType (`int64_t`), the default - value for @a number_integer_t is: + case 0x9F: // array (indefinite length) + return get_cbor_array(json_sax_t::no_limit); + + // map (0x00..0x17 pairs of data items follow) + case 0xA0: + case 0xA1: + case 0xA2: + case 0xA3: + case 0xA4: + case 0xA5: + case 0xA6: + case 0xA7: + case 0xA8: + case 0xA9: + case 0xAA: + case 0xAB: + case 0xAC: + case 0xAD: + case 0xAE: + case 0xAF: + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + return get_cbor_object(static_cast(current & 0x1F)); + + case 0xB8: // map (one-byte uint8_t for n follows) + { + uint8_t len; + return get_number(len) and get_cbor_object(static_cast(len)); + } - @code {.cpp} - int64_t - @endcode + case 0xB9: // map (two-byte uint16_t for n follow) + { + uint16_t len; + return get_number(len) and get_cbor_object(static_cast(len)); + } - #### Default behavior + case 0xBA: // map (four-byte uint32_t for n follow) + { + uint32_t len; + return get_number(len) and get_cbor_object(static_cast(len)); + } - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in integer literals lead to an interpretation as octal - number. Internally, the value will be stored as decimal number. For - instance, the C++ integer literal `010` will be serialized to `8`. - During deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. + case 0xBB: // map (eight-byte uint64_t for n follow) + { + uint64_t len; + return get_number(len) and get_cbor_object(static_cast(len)); + } - #### Limits + case 0xBF: // map (indefinite length) + return get_cbor_object(json_sax_t::no_limit); - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the range and precision of numbers. + case 0xF4: // false + return sax->boolean(false); - When the default type is used, the maximal integer number that can be - stored is `9223372036854775807` (INT64_MAX) and the minimal integer number - that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers - that are out of range will yield over/underflow when used in a - constructor. During deserialization, too large or small integer numbers - will be automatically be stored as @ref number_unsigned_t or @ref - number_float_t. + case 0xF5: // true + return sax->boolean(true); - [RFC 7159](http://rfc7159.net/rfc7159) further states: - > Note that when such software is used, numbers that are integers and are - > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense - > that implementations will agree exactly on their numeric values. + case 0xF6: // null + return sax->null(); - As this range is a subrange of the exactly supported range [INT64_MIN, - INT64_MAX], this class's integer type is interoperable. + case 0xF9: // Half-Precision Float (two-byte IEEE 754) + { + const int byte1 = get(); + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + const int byte2 = get(); + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } - #### Storage + // code from RFC 7049, Appendix D, Figure 3: + // As half-precision floating-point numbers were only added + // to IEEE 754 in 2008, today's programming platforms often + // still only have limited support for them. It is very + // easy to include at least decoding support for them even + // without such support. An example of a small decoder for + // half-precision floating-point numbers in the C language + // is shown in Fig. 3. + const int half = (byte1 << 8) + byte2; + const int exp = (half >> 10) & 0x1F; + const int mant = half & 0x3FF; + double val; + if (exp == 0) + { + val = std::ldexp(mant, -24); + } + else if (exp != 31) + { + val = std::ldexp(mant + 1024, exp - 25); + } + else + { + val = (mant == 0) ? std::numeric_limits::infinity() + : std::numeric_limits::quiet_NaN(); + } + return sax->number_float((half & 0x8000) != 0 ? -val : val, ""); + } - Integer number values are stored directly inside a @ref basic_json type. + case 0xFA: // Single-Precision Float (four-byte IEEE 754) + { + float number; + return get_number(number) and sax->number_float(static_cast(number), ""); + } - @sa @ref number_float_t -- type for number values (floating-point) + case 0xFB: // Double-Precision Float (eight-byte IEEE 754) + { + double number; + return get_number(number) and sax->number_float(number, ""); + } - @sa @ref number_unsigned_t -- type for number values (unsigned integer) + default: // anything else (0xFF is handled inside the other types) + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, "error reading CBOR; last byte: 0x" + last_token)); + } + } + } - @since version 1.0.0 + /*! + @return whether a valid MessagePack value was passed to the SAX parser */ - using number_integer_t = NumberIntegerType; + bool parse_msgpack_internal() + { + switch (get()) + { + // EOF + case std::char_traits::eof(): + return unexpect_eof(); + + // positive fixint + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0A: + case 0x0B: + case 0x0C: + case 0x0D: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + case 0x18: + case 0x19: + case 0x1A: + case 0x1B: + case 0x1C: + case 0x1D: + case 0x1E: + case 0x1F: + case 0x20: + case 0x21: + case 0x22: + case 0x23: + case 0x24: + case 0x25: + case 0x26: + case 0x27: + case 0x28: + case 0x29: + case 0x2A: + case 0x2B: + case 0x2C: + case 0x2D: + case 0x2E: + case 0x2F: + case 0x30: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + case 0x38: + case 0x39: + case 0x3A: + case 0x3B: + case 0x3C: + case 0x3D: + case 0x3E: + case 0x3F: + case 0x40: + case 0x41: + case 0x42: + case 0x43: + case 0x44: + case 0x45: + case 0x46: + case 0x47: + case 0x48: + case 0x49: + case 0x4A: + case 0x4B: + case 0x4C: + case 0x4D: + case 0x4E: + case 0x4F: + case 0x50: + case 0x51: + case 0x52: + case 0x53: + case 0x54: + case 0x55: + case 0x56: + case 0x57: + case 0x58: + case 0x59: + case 0x5A: + case 0x5B: + case 0x5C: + case 0x5D: + case 0x5E: + case 0x5F: + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + case 0x78: + case 0x79: + case 0x7A: + case 0x7B: + case 0x7C: + case 0x7D: + case 0x7E: + case 0x7F: + return sax->number_unsigned(static_cast(current)); + + // fixmap + case 0x80: + case 0x81: + case 0x82: + case 0x83: + case 0x84: + case 0x85: + case 0x86: + case 0x87: + case 0x88: + case 0x89: + case 0x8A: + case 0x8B: + case 0x8C: + case 0x8D: + case 0x8E: + case 0x8F: + return get_msgpack_object(static_cast(current & 0x0F)); + + // fixarray + case 0x90: + case 0x91: + case 0x92: + case 0x93: + case 0x94: + case 0x95: + case 0x96: + case 0x97: + case 0x98: + case 0x99: + case 0x9A: + case 0x9B: + case 0x9C: + case 0x9D: + case 0x9E: + case 0x9F: + return get_msgpack_array(static_cast(current & 0x0F)); + + // fixstr + case 0xA0: + case 0xA1: + case 0xA2: + case 0xA3: + case 0xA4: + case 0xA5: + case 0xA6: + case 0xA7: + case 0xA8: + case 0xA9: + case 0xAA: + case 0xAB: + case 0xAC: + case 0xAD: + case 0xAE: + case 0xAF: + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + case 0xB8: + case 0xB9: + case 0xBA: + case 0xBB: + case 0xBC: + case 0xBD: + case 0xBE: + case 0xBF: + { + string_t s; + return get_msgpack_string(s) and sax->string(s); + } - /*! - @brief a type for a number (unsigned) + case 0xC0: // nil + return sax->null(); - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. + case 0xC2: // false + return sax->boolean(false); - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. + case 0xC3: // true + return sax->boolean(true); - To store unsigned integer numbers in C++, a type is defined by the - template parameter @a NumberUnsignedType which chooses the type to use. + case 0xCA: // float 32 + { + float number; + return get_number(number) and sax->number_float(static_cast(number), ""); + } - #### Default type + case 0xCB: // float 64 + { + double number; + return get_number(number) and sax->number_float(number, ""); + } - With the default values for @a NumberUnsignedType (`uint64_t`), the - default value for @a number_unsigned_t is: + case 0xCC: // uint 8 + { + uint8_t number; + return get_number(number) and sax->number_unsigned(number); + } - @code {.cpp} - uint64_t - @endcode + case 0xCD: // uint 16 + { + uint16_t number; + return get_number(number) and sax->number_unsigned(number); + } - #### Default behavior + case 0xCE: // uint 32 + { + uint32_t number; + return get_number(number) and sax->number_unsigned(number); + } - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in integer literals lead to an interpretation as octal - number. Internally, the value will be stored as decimal number. For - instance, the C++ integer literal `010` will be serialized to `8`. - During deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. + case 0xCF: // uint 64 + { + uint64_t number; + return get_number(number) and sax->number_unsigned(number); + } - #### Limits + case 0xD0: // int 8 + { + int8_t number; + return get_number(number) and sax->number_integer(number); + } - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the range and precision of numbers. + case 0xD1: // int 16 + { + int16_t number; + return get_number(number) and sax->number_integer(number); + } - When the default type is used, the maximal integer number that can be - stored is `18446744073709551615` (UINT64_MAX) and the minimal integer - number that can be stored is `0`. Integer numbers that are out of range - will yield over/underflow when used in a constructor. During - deserialization, too large or small integer numbers will be automatically - be stored as @ref number_integer_t or @ref number_float_t. + case 0xD2: // int 32 + { + int32_t number; + return get_number(number) and sax->number_integer(number); + } - [RFC 7159](http://rfc7159.net/rfc7159) further states: - > Note that when such software is used, numbers that are integers and are - > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense - > that implementations will agree exactly on their numeric values. + case 0xD3: // int 64 + { + int64_t number; + return get_number(number) and sax->number_integer(number); + } - As this range is a subrange (when considered in conjunction with the - number_integer_t type) of the exactly supported range [0, UINT64_MAX], - this class's integer type is interoperable. + case 0xD9: // str 8 + case 0xDA: // str 16 + case 0xDB: // str 32 + { + string_t s; + return get_msgpack_string(s) and sax->string(s); + } - #### Storage + case 0xDC: // array 16 + { + uint16_t len; + return get_number(len) and get_msgpack_array(static_cast(len)); + } - Integer number values are stored directly inside a @ref basic_json type. + case 0xDD: // array 32 + { + uint32_t len; + return get_number(len) and get_msgpack_array(static_cast(len)); + } - @sa @ref number_float_t -- type for number values (floating-point) - @sa @ref number_integer_t -- type for number values (integer) + case 0xDE: // map 16 + { + uint16_t len; + return get_number(len) and get_msgpack_object(static_cast(len)); + } - @since version 2.0.0 - */ - using number_unsigned_t = NumberUnsignedType; + case 0xDF: // map 32 + { + uint32_t len; + return get_number(len) and get_msgpack_object(static_cast(len)); + } + + // negative fixint + case 0xE0: + case 0xE1: + case 0xE2: + case 0xE3: + case 0xE4: + case 0xE5: + case 0xE6: + case 0xE7: + case 0xE8: + case 0xE9: + case 0xEA: + case 0xEB: + case 0xEC: + case 0xED: + case 0xEE: + case 0xEF: + case 0xF0: + case 0xF1: + case 0xF2: + case 0xF3: + case 0xF4: + case 0xF5: + case 0xF6: + case 0xF7: + case 0xF8: + case 0xF9: + case 0xFA: + case 0xFB: + case 0xFC: + case 0xFD: + case 0xFE: + case 0xFF: + return sax->number_integer(static_cast(current)); + + default: // anything else + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, "error reading MessagePack; last byte: 0x" + last_token)); + } + } + } /*! - @brief a type for a number (floating-point) + @param[in] get_char whether a new character should be retrieved from the + input (true, default) or whether the last read + character should be considered instead - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. + @return whether a valid UBJSON value was passed to the SAX parser + */ + bool parse_ubjson_internal(const bool get_char = true) + { + return get_ubjson_value(get_char ? get_ignore_noop() : current); + } - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. + /*! + @brief get next character from the input - To store floating-point numbers in C++, a type is defined by the template - parameter @a NumberFloatType which chooses the type to use. + This function provides the interface to the used input adapter. It does + not throw in case the input reached EOF, but returns a -'ve valued + `std::char_traits::eof()` in that case. - #### Default type + @return character read from the input + */ + int get() + { + ++chars_read; + return (current = ia->get_character()); + } - With the default values for @a NumberFloatType (`double`), the default - value for @a number_float_t is: + /*! + @return character read from the input after ignoring all 'N' entries + */ + int get_ignore_noop() + { + do + { + get(); + } + while (current == 'N'); - @code {.cpp} - double - @endcode + return current; + } - #### Default behavior + /* + @brief read a number from the input - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in floating-point literals will be ignored. Internally, - the value will be stored as decimal number. For instance, the C++ - floating-point literal `01.2` will be serialized to `1.2`. During - deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. + @tparam NumberType the type of the number + @param[out] result number of type @a NumberType - #### Limits + @return whether conversion completed - [RFC 7159](http://rfc7159.net/rfc7159) states: - > This specification allows implementations to set limits on the range and - > precision of numbers accepted. Since software that implements IEEE - > 754-2008 binary64 (double precision) numbers is generally available and - > widely used, good interoperability can be achieved by implementations - > that expect no more precision or range than these provide, in the sense - > that implementations will approximate JSON numbers within the expected - > precision. + @note This function needs to respect the system's endianess, because + bytes in CBOR, MessagePack, and UBJSON are stored in network order + (big endian) and therefore need reordering on little endian systems. + */ + template + bool get_number(NumberType& result) + { + // step 1: read input into array with system's byte order + std::array vec; + for (std::size_t i = 0; i < sizeof(NumberType); ++i) + { + get(); + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } - This implementation does exactly follow this approach, as it uses double - precision floating-point numbers. Note values smaller than - `-1.79769313486232e+308` and values greater than `1.79769313486232e+308` - will be stored as NaN internally and be serialized to `null`. + // reverse byte order prior to conversion if necessary + if (is_little_endian) + { + vec[sizeof(NumberType) - i - 1] = static_cast(current); + } + else + { + vec[i] = static_cast(current); // LCOV_EXCL_LINE + } + } - #### Storage + // step 2: convert array into number of type T and return + std::memcpy(&result, vec.data(), sizeof(NumberType)); + return true; + } - Floating-point number values are stored directly inside a @ref basic_json - type. + /*! + @brief create a string by reading characters from the input - @sa @ref number_integer_t -- type for number values (integer) + @tparam NumberType the type of the number + @param[in] len number of characters to read + @param[out] string created by reading @a len bytes - @sa @ref number_unsigned_t -- type for number values (unsigned integer) + @return whether string creation completed - @since version 1.0.0 + @note We can not reserve @a len bytes for the result, because @a len + may be too large. Usually, @ref unexpect_eof() detects the end of + the input before we run out of string memory. */ - using number_float_t = NumberFloatType; - - /// @} - - private: - - /// helper for exception-safe object creation - template - static T* create(Args&& ... args) + template + bool get_string(const NumberType len, string_t& result) { - AllocatorType alloc; - auto deleter = [&](T * object) + bool success = true; + std::generate_n(std::back_inserter(result), len, [this, &success]() { - alloc.deallocate(object, 1); - }; - std::unique_ptr object(alloc.allocate(1), deleter); - alloc.construct(object.get(), std::forward(args)...); - assert(object != nullptr); - return object.release(); + get(); + if (JSON_UNLIKELY(not unexpect_eof())) + { + success = false; + } + return static_cast(current); + }); + return success; } - //////////////////////// - // JSON value storage // - //////////////////////// - /*! - @brief a JSON value - - The actual storage for a JSON value of the @ref basic_json class. This - union combines the different storage types for the JSON value types - defined in @ref value_t. + @brief reads a CBOR string - JSON type | value_t type | used type - --------- | --------------- | ------------------------ - object | object | pointer to @ref object_t - array | array | pointer to @ref array_t - string | string | pointer to @ref string_t - boolean | boolean | @ref boolean_t - number | number_integer | @ref number_integer_t - number | number_unsigned | @ref number_unsigned_t - number | number_float | @ref number_float_t - null | null | *no value is stored* + This function first reads starting bytes to determine the expected + string length and then copies this number of bytes into a string. + Additionally, CBOR's strings with indefinite lengths are supported. - @note Variable-length types (objects, arrays, and strings) are stored as - pointers. The size of the union should not exceed 64 bits if the default - value types are used. + @param[out] result created string - @since version 1.0.0 + @return whether string creation completed */ - union json_value + bool get_cbor_string(string_t& result) { - /// object (stored with pointer to save storage) - object_t* object; - /// array (stored with pointer to save storage) - array_t* array; - /// string (stored with pointer to save storage) - string_t* string; - /// boolean - boolean_t boolean; - /// number (integer) - number_integer_t number_integer; - /// number (unsigned integer) - number_unsigned_t number_unsigned; - /// number (floating-point) - number_float_t number_float; + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + + switch (current) + { + // UTF-8 string (0x00..0x17 bytes follow) + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + { + return get_string(current & 0x1F, result); + } - /// default constructor (for null values) - json_value() = default; - /// constructor for booleans - json_value(boolean_t v) noexcept : boolean(v) {} - /// constructor for numbers (integer) - json_value(number_integer_t v) noexcept : number_integer(v) {} - /// constructor for numbers (unsigned) - json_value(number_unsigned_t v) noexcept : number_unsigned(v) {} - /// constructor for numbers (floating-point) - json_value(number_float_t v) noexcept : number_float(v) {} - /// constructor for empty values of a given type - json_value(value_t t) - { - switch (t) + case 0x78: // UTF-8 string (one-byte uint8_t for n follows) + { + uint8_t len; + return get_number(len) and get_string(len, result); + } + + case 0x79: // UTF-8 string (two-byte uint16_t for n follow) + { + uint16_t len; + return get_number(len) and get_string(len, result); + } + + case 0x7A: // UTF-8 string (four-byte uint32_t for n follow) + { + uint32_t len; + return get_number(len) and get_string(len, result); + } + + case 0x7B: // UTF-8 string (eight-byte uint64_t for n follow) { - case value_t::object: - { - object = create(); - break; - } + uint64_t len; + return get_number(len) and get_string(len, result); + } - case value_t::array: + case 0x7F: // UTF-8 string (indefinite length) + { + while (get() != 0xFF) { - array = create(); - break; + string_t chunk; + if (not get_cbor_string(chunk)) + { + return false; + } + result.append(chunk); } + return true; + } - case value_t::string: - { - string = create(""); - break; - } + default: + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "expected a CBOR string; last byte: 0x" + last_token)); + } + } + } - case value_t::boolean: + /*! + @param[in] len the length of the array or json_sax_t::no_limit for an + array of indefinite size + @return whether array creation completed + */ + bool get_cbor_array(const std::size_t len) + { + if (JSON_UNLIKELY(not sax->start_array(len))) + { + return false; + } + + if (len != json_sax_t::no_limit) + for (std::size_t i = 0; i < len; ++i) + { + if (JSON_UNLIKELY(not parse_cbor_internal())) { - boolean = boolean_t(false); - break; + return false; } - - case value_t::number_integer: + } + else + { + while (get() != 0xFF) + { + if (JSON_UNLIKELY(not parse_cbor_internal(false))) { - number_integer = number_integer_t(0); - break; + return false; } + } + } - case value_t::number_unsigned: + return sax->end_array(); + } + + /*! + @param[in] len the length of the object or json_sax_t::no_limit for an + object of indefinite size + @return whether object creation completed + */ + bool get_cbor_object(const std::size_t len) + { + if (not JSON_UNLIKELY(sax->start_object(len))) + { + return false; + } + + string_t key; + if (len != json_sax_t::no_limit) + { + for (std::size_t i = 0; i < len; ++i) + { + get(); + if (JSON_UNLIKELY(not get_cbor_string(key) or not sax->key(key))) { - number_unsigned = number_unsigned_t(0); - break; + return false; } - case value_t::number_float: + if (JSON_UNLIKELY(not parse_cbor_internal())) { - number_float = number_float_t(0.0); - break; + return false; } - - case value_t::null: + key.clear(); + } + } + else + { + while (get() != 0xFF) + { + if (JSON_UNLIKELY(not get_cbor_string(key) or not sax->key(key))) { - break; + return false; } - default: + if (JSON_UNLIKELY(not parse_cbor_internal())) { - if (JSON_UNLIKELY(t == value_t::null)) - { - JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 2.1.1")); // LCOV_EXCL_LINE - } - break; + return false; } + key.clear(); } } - /// constructor for strings - json_value(const string_t& value) - { - string = create(value); - } + return sax->end_object(); + } - /// constructor for objects - json_value(const object_t& value) - { - object = create(value); - } + /*! + @brief reads a MessagePack string - /// constructor for arrays - json_value(const array_t& value) - { - array = create(value); - } - }; + This function first reads starting bytes to determine the expected + string length and then copies this number of bytes into a string. - /*! - @brief checks the class invariants + @param[out] result created string - This function asserts the class invariants. It needs to be called at the - end of every constructor to make sure that created objects respect the - invariant. Furthermore, it has to be called each time the type of a JSON - value is changed, because the invariant expresses a relationship between - @a m_type and @a m_value. + @return whether string creation completed */ - void assert_invariant() const + bool get_msgpack_string(string_t& result) { - assert(m_type != value_t::object or m_value.object != nullptr); - assert(m_type != value_t::array or m_value.array != nullptr); - assert(m_type != value_t::string or m_value.string != nullptr); - } + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + + switch (current) + { + // fixstr + case 0xA0: + case 0xA1: + case 0xA2: + case 0xA3: + case 0xA4: + case 0xA5: + case 0xA6: + case 0xA7: + case 0xA8: + case 0xA9: + case 0xAA: + case 0xAB: + case 0xAC: + case 0xAD: + case 0xAE: + case 0xAF: + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + case 0xB8: + case 0xB9: + case 0xBA: + case 0xBB: + case 0xBC: + case 0xBD: + case 0xBE: + case 0xBF: + { + return get_string(current & 0x1F, result); + } - public: - ////////////////////////// - // JSON parser callback // - ////////////////////////// + case 0xD9: // str 8 + { + uint8_t len; + return get_number(len) and get_string(len, result); + } - /*! - @brief JSON callback events + case 0xDA: // str 16 + { + uint16_t len; + return get_number(len) and get_string(len, result); + } - This enumeration lists the parser events that can trigger calling a - callback function of type @ref parser_callback_t during parsing. + case 0xDB: // str 32 + { + uint32_t len; + return get_number(len) and get_string(len, result); + } - @image html callback_events.png "Example when certain parse events are triggered" + default: + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "expected a MessagePack string; last byte: 0x" + last_token)); + } + } + } - @since version 1.0.0 + /*! + @param[in] len the length of the array + @return whether array creation completed */ - enum class parse_event_t : uint8_t + bool get_msgpack_array(const std::size_t len) { - /// the parser read `{` and started to process a JSON object - object_start, - /// the parser read `}` and finished processing a JSON object - object_end, - /// the parser read `[` and started to process a JSON array - array_start, - /// the parser read `]` and finished processing a JSON array - array_end, - /// the parser read a key of a value in an object - key, - /// the parser finished reading a JSON value - value - }; + if (JSON_UNLIKELY(not sax->start_array(len))) + { + return false; + } - /*! - @brief per-element parser callback type + for (std::size_t i = 0; i < len; ++i) + { + if (JSON_UNLIKELY(not parse_msgpack_internal())) + { + return false; + } + } - With a parser callback function, the result of parsing a JSON text can be - influenced. When passed to @ref parse(std::istream&, const - parser_callback_t) or @ref parse(const CharT, const parser_callback_t), - it is called on certain events (passed as @ref parse_event_t via parameter - @a event) with a set recursion depth @a depth and context JSON value - @a parsed. The return value of the callback function is a boolean - indicating whether the element that emitted the callback shall be kept or - not. + return sax->end_array(); + } - We distinguish six scenarios (determined by the event type) in which the - callback function can be called. The following table describes the values - of the parameters @a depth, @a event, and @a parsed. + /*! + @param[in] len the length of the object + @return whether object creation completed + */ + bool get_msgpack_object(const std::size_t len) + { + if (JSON_UNLIKELY(not sax->start_object(len))) + { + return false; + } - parameter @a event | description | parameter @a depth | parameter @a parsed - ------------------ | ----------- | ------------------ | ------------------- - parse_event_t::object_start | the parser read `{` and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded - parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key - parse_event_t::object_end | the parser read `}` and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object - parse_event_t::array_start | the parser read `[` and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded - parse_event_t::array_end | the parser read `]` and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array - parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value + string_t key; + for (std::size_t i = 0; i < len; ++i) + { + get(); + if (JSON_UNLIKELY(not get_msgpack_string(key) or not sax->key(key))) + { + return false; + } - @image html callback_events.png "Example when certain parse events are triggered" + if (JSON_UNLIKELY(not parse_msgpack_internal())) + { + return false; + } + key.clear(); + } - Discarding a value (i.e., returning `false`) has different effects - depending on the context in which function was called: + return sax->end_object(); + } - - Discarded values in structured types are skipped. That is, the parser - will behave as if the discarded value was never read. - - In case a value outside a structured type is skipped, it is replaced - with `null`. This case happens if the top-level element is skipped. + /*! + @brief reads a UBJSON string - @param[in] depth the depth of the recursion during parsing + This function is either called after reading the 'S' byte explicitly + indicating a string, or in case of an object key where the 'S' byte can be + left out. - @param[in] event an event of type parse_event_t indicating the context in - the callback function has been called + @param[out] result created string + @param[in] get_char whether a new character should be retrieved from the + input (true, default) or whether the last read + character should be considered instead - @param[in,out] parsed the current intermediate parse result; note that - writing to this value has no effect for parse_event_t::key events + @return whether string creation completed + */ + bool get_ubjson_string(string_t& result, const bool get_char = true) + { + if (get_char) + { + get(); // TODO: may we ignore N here? + } - @return Whether the JSON value which called the function during parsing - should be kept (`true`) or not (`false`). In the latter case, it is either - skipped completely or replaced by an empty discarded object. + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } - @sa @ref parse(std::istream&, parser_callback_t) or - @ref parse(const CharT, const parser_callback_t) for examples + switch (current) + { + case 'U': + { + uint8_t len; + return get_number(len) and get_string(len, result); + } - @since version 1.0.0 - */ - using parser_callback_t = std::function; + case 'i': + { + int8_t len; + return get_number(len) and get_string(len, result); + } + case 'I': + { + int16_t len; + return get_number(len) and get_string(len, result); + } - ////////////////// - // constructors // - ////////////////// + case 'l': + { + int32_t len; + return get_number(len) and get_string(len, result); + } - /// @name constructors and destructors - /// Constructors of class @ref basic_json, copy/move constructor, copy - /// assignment, static functions creating objects, and the destructor. - /// @{ + case 'L': + { + int64_t len; + return get_number(len) and get_string(len, result); + } - /*! - @brief create an empty value with a given type + default: + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "expected a UBJSON string; last byte: 0x" + last_token)); + } + } - Create an empty JSON value with a given type. The value will be default - initialized with an empty value which depends on the type: + /*! + @param[out] result determined size + @return whether size determination completed + */ + bool get_ubjson_size_value(std::size_t& result) + { + switch (get_ignore_noop()) + { + case 'U': + { + uint8_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - Value type | initial value - ----------- | ------------- - null | `null` - boolean | `false` - string | `""` - number | `0` - object | `{}` - array | `[]` + case 'i': + { + int8_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - @param[in] value_type the type of the value to create + case 'I': + { + int16_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - @complexity Constant. + case 'l': + { + int32_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - @liveexample{The following code shows the constructor for different @ref - value_t values,basic_json__value_t} + case 'L': + { + int64_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - @since version 1.0.0 - */ - basic_json(const value_t value_type) - : m_type(value_type), m_value(value_type) - { - assert_invariant(); + default: + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "byte after '#' must denote a number type; last byte: 0x" + last_token)); + } + } } /*! - @brief create a null object - - Create a `null` JSON value. It either takes a null pointer as parameter - (explicitly creating `null`) or no parameter (implicitly creating `null`). - The passed null pointer itself is not read -- it is only used to choose - the right constructor. - - @complexity Constant. + @brief determine the type and size for a container - @exceptionsafety No-throw guarantee: this constructor never throws - exceptions. + In the optimized UBJSON format, a type and a size can be provided to allow + for a more compact representation. - @liveexample{The following code shows the constructor with and without a - null pointer parameter.,basic_json__nullptr_t} + @param[out] result pair of the size and the type - @since version 1.0.0 + @return whether pair creation completed */ - basic_json(std::nullptr_t = nullptr) noexcept - : basic_json(value_t::null) + bool get_ubjson_size_type(std::pair& result) { - assert_invariant(); - } - - /*! - @brief create a JSON value - - This is a "catch all" constructor for all compatible JSON types; that is, - types for which a `to_json()` method exsits. The constructor forwards the - parameter @a val to that method (to `json_serializer::to_json` method - with `U = uncvref_t`, to be exact). + result.first = string_t::npos; // size + result.second = 0; // type - Template type @a CompatibleType includes, but is not limited to, the - following types: - - **arrays**: @ref array_t and all kinds of compatible containers such as - `std::vector`, `std::deque`, `std::list`, `std::forward_list`, - `std::array`, `std::set`, `std::unordered_set`, `std::multiset`, and - `unordered_multiset` with a `value_type` from which a @ref basic_json - value can be constructed. - - **objects**: @ref object_t and all kinds of compatible associative - containers such as `std::map`, `std::unordered_map`, `std::multimap`, - and `std::unordered_multimap` with a `key_type` compatible to - @ref string_t and a `value_type` from which a @ref basic_json value can - be constructed. - - **strings**: @ref string_t, string literals, and all compatible string - containers can be used. - - **numbers**: @ref number_integer_t, @ref number_unsigned_t, - @ref number_float_t, and all convertible number types such as `int`, - `size_t`, `int64_t`, `float` or `double` can be used. - - **boolean**: @ref boolean_t / `bool` can be used. + get_ignore_noop(); - See the examples below. + if (current == '$') + { + result.second = get(); // must not ignore 'N', because 'N' maybe the type + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } - @tparam CompatibleType a type such that: - - @a CompatibleType is not derived from `std::istream`, - - @a CompatibleType is not @ref basic_json (to avoid hijacking copy/move - constructors), - - @a CompatibleType is not a @ref basic_json nested type (e.g., - @ref json_pointer, @ref iterator, etc ...) - - @ref @ref json_serializer has a - `to_json(basic_json_t&, CompatibleType&&)` method + get_ignore_noop(); + if (JSON_UNLIKELY(current != '#')) + { + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, "expected '#' after UBJSON type information; last byte: 0x" + last_token)); + } - @tparam U = `uncvref_t` + return get_ubjson_size_value(result.first); + } + else if (current == '#') + { + return get_ubjson_size_value(result.first); + } + return true; + } - @param[in] val the value to be forwarded + /*! + @param prefix the previously read or set type prefix + @return whether value creation completed + */ + bool get_ubjson_value(const int prefix) + { + switch (prefix) + { + case std::char_traits::eof(): // EOF + return unexpect_eof(); - @complexity Usually linear in the size of the passed @a val, also - depending on the implementation of the called `to_json()` - method. + case 'T': // true + return sax->boolean(true); + case 'F': // false + return sax->boolean(false); - @throw what `json_serializer::to_json()` throws + case 'Z': // null + return sax->null(); - @liveexample{The following code shows the constructor with several - compatible types.,basic_json__CompatibleType} + case 'U': + { + uint8_t number; + return get_number(number) and sax->number_unsigned(number); + } - @since version 2.1.0 - */ - template, - detail::enable_if_t::value and - not std::is_same::value and - not detail::is_basic_json_nested_type< - basic_json_t, U>::value and - detail::has_to_json::value, - int> = 0> - basic_json(CompatibleType && val) noexcept(noexcept(JSONSerializer::to_json( - std::declval(), std::forward(val)))) - { - JSONSerializer::to_json(*this, std::forward(val)); - assert_invariant(); - } + case 'i': + { + int8_t number; + return get_number(number) and sax->number_integer(number); + } - /*! - @brief create a container (array or object) from an initializer list + case 'I': + { + int16_t number; + return get_number(number) and sax->number_integer(number); + } - Creates a JSON value of type array or object from the passed initializer - list @a init. In case @a type_deduction is `true` (default), the type of - the JSON value to be created is deducted from the initializer list @a init - according to the following rules: + case 'l': + { + int32_t number; + return get_number(number) and sax->number_integer(number); + } - 1. If the list is empty, an empty JSON object value `{}` is created. - 2. If the list consists of pairs whose first element is a string, a JSON - object value is created where the first elements of the pairs are - treated as keys and the second elements are as values. - 3. In all other cases, an array is created. + case 'L': + { + int64_t number; + return get_number(number) and sax->number_integer(number); + } - The rules aim to create the best fit between a C++ initializer list and - JSON values. The rationale is as follows: + case 'd': + { + float number; + return get_number(number) and sax->number_float(static_cast(number), ""); + } - 1. The empty initializer list is written as `{}` which is exactly an empty - JSON object. - 2. C++ has now way of describing mapped types other than to list a list of - pairs. As JSON requires that keys must be of type string, rule 2 is the - weakest constraint one can pose on initializer lists to interpret them - as an object. - 3. In all other cases, the initializer list could not be interpreted as - JSON object type, so interpreting it as JSON array type is safe. + case 'D': + { + double number; + return get_number(number) and sax->number_float(number, ""); + } - With the rules described above, the following JSON values cannot be - expressed by an initializer list: + case 'C': // char + { + get(); + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + if (JSON_UNLIKELY(current > 127)) + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "byte after 'C' must be in range 0x00..0x7F; last byte: 0x" + last_token)); + } + string_t s(1, static_cast(current)); + return sax->string(s); + } - - the empty array (`[]`): use @ref array(std::initializer_list) - with an empty initializer list in this case - - arrays whose elements satisfy rule 2: use @ref - array(std::initializer_list) with the same initializer list - in this case + case 'S': // string + { + string_t s; + return get_ubjson_string(s) and sax->string(s); + } - @note When used without parentheses around an empty initializer list, @ref - basic_json() is called instead of this function, yielding the JSON null - value. + case '[': // array + return get_ubjson_array(); - @param[in] init initializer list with JSON values + case '{': // object + return get_ubjson_object(); - @param[in] type_deduction internal parameter; when set to `true`, the type - of the JSON value is deducted from the initializer list @a init; when set - to `false`, the type provided via @a manual_type is forced. This mode is - used by the functions @ref array(std::initializer_list) and - @ref object(std::initializer_list). + default: // anything else + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, "error reading UBJSON; last byte: 0x" + last_token)); + } + } + } - @param[in] manual_type internal parameter; when @a type_deduction is set - to `false`, the created JSON value will use the provided type (only @ref - value_t::array and @ref value_t::object are valid); when @a type_deduction - is set to `true`, this parameter has no effect + /*! + @return whether array creation completed + */ + bool get_ubjson_array() + { + std::pair size_and_type; + if (JSON_UNLIKELY(not get_ubjson_size_type(size_and_type))) + { + return false; + } - @throw type_error.301 if @a type_deduction is `false`, @a manual_type is - `value_t::object`, but @a init contains an element which is not a pair - whose first element is a string. In this case, the constructor could not - create an object. If @a type_deduction would have be `true`, an array - would have been created. See @ref object(std::initializer_list) - for an example. + if (size_and_type.first != string_t::npos) + { + if (JSON_UNLIKELY(not sax->start_array(size_and_type.first))) + { + return false; + } - @complexity Linear in the size of the initializer list @a init. + if (size_and_type.second != 0) + { + if (size_and_type.second != 'N') + { + for (std::size_t i = 0; i < size_and_type.first; ++i) + { + if (JSON_UNLIKELY(not get_ubjson_value(size_and_type.second))) + { + return false; + } + } + } + } + else + { + for (std::size_t i = 0; i < size_and_type.first; ++i) + { + if (JSON_UNLIKELY(not parse_ubjson_internal())) + { + return false; + } + } + } + } + else + { + if (JSON_UNLIKELY(not sax->start_array())) + { + return false; + } - @liveexample{The example below shows how JSON values are created from - initializer lists.,basic_json__list_init_t} + while (current != ']') + { + if (JSON_UNLIKELY(not parse_ubjson_internal(false))) + { + return false; + } + get_ignore_noop(); + } + } - @sa @ref array(std::initializer_list) -- create a JSON array - value from an initializer list - @sa @ref object(std::initializer_list) -- create a JSON object - value from an initializer list + return sax->end_array(); + } - @since version 1.0.0 + /*! + @return whether object creation completed */ - basic_json(std::initializer_list init, - bool type_deduction = true, - value_t manual_type = value_t::array) + bool get_ubjson_object() { - // check if each element is an array with two elements whose first - // element is a string - bool is_an_object = std::all_of(init.begin(), init.end(), - [](const basic_json & element) + std::pair size_and_type; + if (JSON_UNLIKELY(not get_ubjson_size_type(size_and_type))) { - return element.is_array() and element.size() == 2 and element[0].is_string(); - }); + return false; + } - // adjust type if type deduction is not wanted - if (not type_deduction) + string_t key; + if (size_and_type.first != string_t::npos) { - // if array is wanted, do not create an object though possible - if (manual_type == value_t::array) + if (JSON_UNLIKELY(not sax->start_object(size_and_type.first))) { - is_an_object = false; + return false; + } + + if (size_and_type.second != 0) + { + for (std::size_t i = 0; i < size_and_type.first; ++i) + { + if (JSON_UNLIKELY(not get_ubjson_string(key) or not sax->key(key))) + { + return false; + } + if (JSON_UNLIKELY(not get_ubjson_value(size_and_type.second))) + { + return false; + } + key.clear(); + } + } + else + { + for (std::size_t i = 0; i < size_and_type.first; ++i) + { + if (JSON_UNLIKELY(not get_ubjson_string(key) or not sax->key(key))) + { + return false; + } + if (JSON_UNLIKELY(not parse_ubjson_internal())) + { + return false; + } + key.clear(); + } + } + } + else + { + if (JSON_UNLIKELY(not sax->start_object())) + { + return false; } - // if object is wanted but impossible, throw an exception - if (manual_type == value_t::object and not is_an_object) + while (current != '}') { - JSON_THROW(type_error::create(301, "cannot create object from initializer list")); + if (JSON_UNLIKELY(not get_ubjson_string(key, false) or not sax->key(key))) + { + return false; + } + if (JSON_UNLIKELY(not parse_ubjson_internal())) + { + return false; + } + get_ignore_noop(); + key.clear(); } } - if (is_an_object) - { - // the initializer list is a list of pairs -> create object - m_type = value_t::object; - m_value = value_t::object; + return sax->end_object(); + } - std::for_each(init.begin(), init.end(), [this](const basic_json & element) - { - m_value.object->emplace(*(element[0].m_value.string), element[1]); - }); - } - else + /*! + @return whether the last read character is not EOF + */ + bool unexpect_eof() const + { + if (JSON_UNLIKELY(current == std::char_traits::eof())) { - // the initializer list describes an array -> create array - m_type = value_t::array; - m_value.array = create(init); + return sax->parse_error(chars_read, "", parse_error::create(110, chars_read, "unexpected end of input")); } - - assert_invariant(); + return true; } /*! - @brief explicitly create an array from an initializer list - - Creates a JSON array value from a given initializer list. That is, given a - list of values `a, b, c`, creates the JSON value `[a, b, c]`. If the - initializer list is empty, the empty array `[]` is created. - - @note This function is only needed to express two edge cases that cannot - be realized with the initializer list constructor (@ref - basic_json(std::initializer_list, bool, value_t)). These cases - are: - 1. creating an array whose elements are all pairs whose first element is a - string -- in this case, the initializer list constructor would create an - object, taking the first elements as keys - 2. creating an empty array -- passing the empty initializer list to the - initializer list constructor yields an empty object - - @param[in] init initializer list with JSON values to create an array from - (optional) - - @return JSON array value - - @complexity Linear in the size of @a init. - - @liveexample{The following code shows an example for the `array` - function.,array} - - @sa @ref basic_json(std::initializer_list, bool, value_t) -- - create a JSON value from an initializer list - @sa @ref object(std::initializer_list) -- create a JSON object - value from an initializer list - - @since version 1.0.0 + @return a string representation of the last read byte */ - static basic_json array(std::initializer_list init = - std::initializer_list()) + std::string get_token_string() const { - return basic_json(init, false, value_t::array); + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << current; + return ss.str(); } - /*! - @brief explicitly create an object from an initializer list - - Creates a JSON object value from a given initializer list. The initializer - lists elements must be pairs, and their first elements must be strings. If - the initializer list is empty, the empty object `{}` is created. - - @note This function is only added for symmetry reasons. In contrast to the - related function @ref array(std::initializer_list), there are - no cases which can only be expressed by this function. That is, any - initializer list @a init can also be passed to the initializer list - constructor @ref basic_json(std::initializer_list, bool, value_t). + private: + /// input adapter + input_adapter_t ia = nullptr; - @param[in] init initializer list to create an object from (optional) + /// the current character + int current = std::char_traits::eof(); - @return JSON object value + /// the number of characters read + std::size_t chars_read = 0; - @throw type_error.301 if @a init is not a list of pairs whose first - elements are strings. In this case, no object can be created. When such a - value is passed to @ref basic_json(std::initializer_list, bool, value_t), - an array would have been created from the passed initializer list @a init. - See example below. + /// whether we can assume little endianess + const bool is_little_endian = little_endianess(); - @complexity Linear in the size of @a init. + /// the SAX parser + json_sax_t* sax = nullptr; +}; +} +} - @liveexample{The following code shows an example for the `object` - function.,object} +// #include - @sa @ref basic_json(std::initializer_list, bool, value_t) -- - create a JSON value from an initializer list - @sa @ref array(std::initializer_list) -- create a JSON array - value from an initializer list - @since version 1.0.0 - */ - static basic_json object(std::initializer_list init = - std::initializer_list()) - { - return basic_json(init, false, value_t::object); - } +#include // reverse +#include // array +#include // uint8_t, uint16_t, uint32_t, uint64_t +#include // memcpy +#include // numeric_limits - /*! - @brief construct an array with count copies of given value +// #include - Constructs a JSON array value by creating @a cnt copies of a passed value. - In case @a cnt is `0`, an empty array is created. As postcondition, - `std::distance(begin(),end()) == cnt` holds. +// #include - @param[in] cnt the number of JSON copies of @a val to create - @param[in] val the JSON value to copy - @complexity Linear in @a cnt. +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// binary writer // +/////////////////// - @liveexample{The following code shows examples for the @ref - basic_json(size_type\, const basic_json&) - constructor.,basic_json__size_type_basic_json} +/*! +@brief serialization to CBOR and MessagePack values +*/ +template +class binary_writer +{ + public: + /*! + @brief create a binary writer - @since version 1.0.0 + @param[in] adapter output adapter to write to */ - basic_json(size_type cnt, const basic_json& val) - : m_type(value_t::array) + explicit binary_writer(output_adapter_t adapter) : oa(adapter) { - m_value.array = create(cnt, val); - assert_invariant(); + assert(oa); } /*! - @brief construct a JSON container given an iterator range - - Constructs the JSON value with the contents of the range `[first, last)`. - The semantics depends on the different types a JSON value can have: - - In case of primitive types (number, boolean, or string), @a first must - be `begin()` and @a last must be `end()`. In this case, the value is - copied. Otherwise, invalid_iterator.204 is thrown. - - In case of structured types (array, object), the constructor behaves as - similar versions for `std::vector`. - - In case of a null type, invalid_iterator.206 is thrown. - - @tparam InputIT an input iterator type (@ref iterator or @ref - const_iterator) - - @param[in] first begin of the range to copy from (included) - @param[in] last end of the range to copy from (excluded) - - @pre Iterators @a first and @a last must be initialized. **This - precondition is enforced with an assertion.** - - @pre Range `[first, last)` is valid. Usually, this precondition cannot be - checked efficiently. Only certain edge cases are detected; see the - description of the exceptions below. - - @throw invalid_iterator.201 if iterators @a first and @a last are not - compatible (i.e., do not belong to the same JSON value). In this case, - the range `[first, last)` is undefined. - @throw invalid_iterator.204 if iterators @a first and @a last belong to a - primitive type (number, boolean, or string), but @a first does not point - to the first element any more. In this case, the range `[first, last)` is - undefined. See example code below. - @throw invalid_iterator.206 if iterators @a first and @a last belong to a - null value. In this case, the range `[first, last)` is undefined. - - @complexity Linear in distance between @a first and @a last. - - @liveexample{The example below shows several ways to create JSON values by - specifying a subrange with iterators.,basic_json__InputIt_InputIt} - - @since version 1.0.0 + @brief[in] j JSON value to serialize */ - template::value or - std::is_same::value, int>::type = 0> - basic_json(InputIT first, InputIT last) + void write_cbor(const BasicJsonType& j) { - assert(first.m_object != nullptr); - assert(last.m_object != nullptr); - - // make sure iterator fits the current value - if (first.m_object != last.m_object) - { - JSON_THROW(invalid_iterator::create(201, "iterators are not compatible")); - } - - // copy type from first iterator - m_type = first.m_object->m_type; - - // check if iterator range is complete for primitive values - switch (m_type) + switch (j.type()) { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: + case value_t::null: { - if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end()) - { - JSON_THROW(invalid_iterator::create(204, "iterators out of range")); - } + oa->write_character(static_cast(0xF6)); break; } - default: + case value_t::boolean: { + oa->write_character(j.m_value.boolean + ? static_cast(0xF5) + : static_cast(0xF4)); break; } - } - switch (m_type) - { case value_t::number_integer: { - m_value.number_integer = first.m_object->m_value.number_integer; + if (j.m_value.number_integer >= 0) + { + // CBOR does not differentiate between positive signed + // integers and unsigned integers. Therefore, we used the + // code from the value_t::number_unsigned case here. + if (j.m_value.number_integer <= 0x17) + { + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x18)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x19)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x1A)); + write_number(static_cast(j.m_value.number_integer)); + } + else + { + oa->write_character(static_cast(0x1B)); + write_number(static_cast(j.m_value.number_integer)); + } + } + else + { + // The conversions below encode the sign in the first + // byte, and the value is converted to a positive number. + const auto positive_number = -1 - j.m_value.number_integer; + if (j.m_value.number_integer >= -24) + { + write_number(static_cast(0x20 + positive_number)); + } + else if (positive_number <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x38)); + write_number(static_cast(positive_number)); + } + else if (positive_number <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x39)); + write_number(static_cast(positive_number)); + } + else if (positive_number <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x3A)); + write_number(static_cast(positive_number)); + } + else + { + oa->write_character(static_cast(0x3B)); + write_number(static_cast(positive_number)); + } + } break; } case value_t::number_unsigned: { - m_value.number_unsigned = first.m_object->m_value.number_unsigned; + if (j.m_value.number_unsigned <= 0x17) + { + write_number(static_cast(j.m_value.number_unsigned)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x18)); + write_number(static_cast(j.m_value.number_unsigned)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x19)); + write_number(static_cast(j.m_value.number_unsigned)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x1A)); + write_number(static_cast(j.m_value.number_unsigned)); + } + else + { + oa->write_character(static_cast(0x1B)); + write_number(static_cast(j.m_value.number_unsigned)); + } break; } case value_t::number_float: { - m_value.number_float = first.m_object->m_value.number_float; - break; - } - - case value_t::boolean: - { - m_value.boolean = first.m_object->m_value.boolean; + oa->write_character(get_cbor_float_prefix(j.m_value.number_float)); + write_number(j.m_value.number_float); break; } case value_t::string: { - m_value = *first.m_object->m_value.string; + // step 1: write control byte and the string length + const auto N = j.m_value.string->size(); + if (N <= 0x17) + { + write_number(static_cast(0x60 + N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x78)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x79)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x7A)); + write_number(static_cast(N)); + } + // LCOV_EXCL_START + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x7B)); + write_number(static_cast(N)); + } + // LCOV_EXCL_STOP + + // step 2: write the string + oa->write_characters( + reinterpret_cast(j.m_value.string->c_str()), + j.m_value.string->size()); break; } - case value_t::object: + case value_t::array: { - m_value.object = create(first.m_it.object_iterator, - last.m_it.object_iterator); + // step 1: write control byte and the array size + const auto N = j.m_value.array->size(); + if (N <= 0x17) + { + write_number(static_cast(0x80 + N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x98)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x99)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x9A)); + write_number(static_cast(N)); + } + // LCOV_EXCL_START + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x9B)); + write_number(static_cast(N)); + } + // LCOV_EXCL_STOP + + // step 2: write each element + for (const auto& el : *j.m_value.array) + { + write_cbor(el); + } break; } - case value_t::array: + case value_t::object: { - m_value.array = create(first.m_it.array_iterator, - last.m_it.array_iterator); + // step 1: write control byte and the object size + const auto N = j.m_value.object->size(); + if (N <= 0x17) + { + write_number(static_cast(0xA0 + N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xB8)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xB9)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xBA)); + write_number(static_cast(N)); + } + // LCOV_EXCL_START + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xBB)); + write_number(static_cast(N)); + } + // LCOV_EXCL_STOP + + // step 2: write each element + for (const auto& el : *j.m_value.object) + { + write_cbor(el.first); + write_cbor(el.second); + } break; } default: - { - JSON_THROW(invalid_iterator::create(206, "cannot construct with iterators from " + - first.m_object->type_name())); - } + break; } - - assert_invariant(); } - - /////////////////////////////////////// - // other constructors and destructor // - /////////////////////////////////////// - /*! - @brief copy constructor - - Creates a copy of a given JSON value. - - @param[in] other the JSON value to copy - - @complexity Linear in the size of @a other. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - As postcondition, it holds: `other == basic_json(other)`. - - @liveexample{The following code shows an example for the copy - constructor.,basic_json__basic_json} - - @since version 1.0.0 + @brief[in] j JSON value to serialize */ - basic_json(const basic_json& other) - : m_type(other.m_type) + void write_msgpack(const BasicJsonType& j) { - // check of passed value is valid - other.assert_invariant(); - - switch (m_type) + switch (j.type()) { - case value_t::object: + case value_t::null: // nil { - m_value = *other.m_value.object; + oa->write_character(static_cast(0xC0)); break; } - case value_t::array: + case value_t::boolean: // true and false { - m_value = *other.m_value.array; + oa->write_character(j.m_value.boolean + ? static_cast(0xC3) + : static_cast(0xC2)); break; } - case value_t::string: + case value_t::number_integer: { - m_value = *other.m_value.string; + if (j.m_value.number_integer >= 0) + { + // MessagePack does not differentiate between positive + // signed integers and unsigned integers. Therefore, we used + // the code from the value_t::number_unsigned case here. + if (j.m_value.number_unsigned < 128) + { + // positive fixnum + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 8 + oa->write_character(static_cast(0xCC)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 16 + oa->write_character(static_cast(0xCD)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 32 + oa->write_character(static_cast(0xCE)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 64 + oa->write_character(static_cast(0xCF)); + write_number(static_cast(j.m_value.number_integer)); + } + } + else + { + if (j.m_value.number_integer >= -32) + { + // negative fixnum + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 8 + oa->write_character(static_cast(0xD0)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 16 + oa->write_character(static_cast(0xD1)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 32 + oa->write_character(static_cast(0xD2)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 64 + oa->write_character(static_cast(0xD3)); + write_number(static_cast(j.m_value.number_integer)); + } + } break; } - case value_t::boolean: + case value_t::number_unsigned: { - m_value = other.m_value.boolean; + if (j.m_value.number_unsigned < 128) + { + // positive fixnum + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 8 + oa->write_character(static_cast(0xCC)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 16 + oa->write_character(static_cast(0xCD)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 32 + oa->write_character(static_cast(0xCE)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 64 + oa->write_character(static_cast(0xCF)); + write_number(static_cast(j.m_value.number_integer)); + } break; } - case value_t::number_integer: + case value_t::number_float: { - m_value = other.m_value.number_integer; + oa->write_character(get_msgpack_float_prefix(j.m_value.number_float)); + write_number(j.m_value.number_float); break; } - case value_t::number_unsigned: + case value_t::string: { - m_value = other.m_value.number_unsigned; + // step 1: write control byte and the string length + const auto N = j.m_value.string->size(); + if (N <= 31) + { + // fixstr + write_number(static_cast(0xA0 | N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // str 8 + oa->write_character(static_cast(0xD9)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // str 16 + oa->write_character(static_cast(0xDA)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // str 32 + oa->write_character(static_cast(0xDB)); + write_number(static_cast(N)); + } + + // step 2: write the string + oa->write_characters( + reinterpret_cast(j.m_value.string->c_str()), + j.m_value.string->size()); break; } - case value_t::number_float: + case value_t::array: { - m_value = other.m_value.number_float; + // step 1: write control byte and the array size + const auto N = j.m_value.array->size(); + if (N <= 15) + { + // fixarray + write_number(static_cast(0x90 | N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // array 16 + oa->write_character(static_cast(0xDC)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // array 32 + oa->write_character(static_cast(0xDD)); + write_number(static_cast(N)); + } + + // step 2: write each element + for (const auto& el : *j.m_value.array) + { + write_msgpack(el); + } break; } - default: + case value_t::object: { + // step 1: write control byte and the object size + const auto N = j.m_value.object->size(); + if (N <= 15) + { + // fixmap + write_number(static_cast(0x80 | (N & 0xF))); + } + else if (N <= (std::numeric_limits::max)()) + { + // map 16 + oa->write_character(static_cast(0xDE)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // map 32 + oa->write_character(static_cast(0xDF)); + write_number(static_cast(N)); + } + + // step 2: write each element + for (const auto& el : *j.m_value.object) + { + write_msgpack(el.first); + write_msgpack(el.second); + } break; } - } - - assert_invariant(); - } - - /*! - @brief move constructor - - Move constructor. Constructs a JSON value with the contents of the given - value @a other using move semantics. It "steals" the resources from @a - other and leaves it as JSON null value. - - @param[in,out] other value to move to this object - - @post @a other is a JSON null value - - @complexity Constant. - - @liveexample{The code below shows the move constructor explicitly called - via std::move.,basic_json__moveconstructor} - - @since version 1.0.0 - */ - basic_json(basic_json&& other) noexcept - : m_type(std::move(other.m_type)), - m_value(std::move(other.m_value)) - { - // check that passed value is valid - other.assert_invariant(); - - // invalidate payload - other.m_type = value_t::null; - other.m_value = {}; - - assert_invariant(); - } - - /*! - @brief copy assignment - - Copy assignment operator. Copies a JSON value via the "copy and swap" - strategy: It is expressed in terms of the copy constructor, destructor, - and the swap() member function. - @param[in] other value to copy from - - @complexity Linear. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - @liveexample{The code below shows and example for the copy assignment. It - creates a copy of value `a` which is then swapped with `b`. Finally\, the - copy of `a` (which is the null value after the swap) is - destroyed.,basic_json__copyassignment} - - @since version 1.0.0 - */ - reference& operator=(basic_json other) noexcept ( - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value and - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value - ) - { - // check that passed value is valid - other.assert_invariant(); - - using std::swap; - swap(m_type, other.m_type); - swap(m_value, other.m_value); - - assert_invariant(); - return *this; + default: + break; + } } /*! - @brief destructor - - Destroys the JSON value and frees all allocated memory. - - @complexity Linear. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - All stored elements are destroyed and all memory is freed. - - @since version 1.0.0 + @param[in] j JSON value to serialize + @param[in] use_count whether to use '#' prefixes (optimized format) + @param[in] use_type whether to use '$' prefixes (optimized format) + @param[in] add_prefix whether prefixes need to be used for this value */ - ~basic_json() + void write_ubjson(const BasicJsonType& j, const bool use_count, + const bool use_type, const bool add_prefix = true) { - assert_invariant(); - - switch (m_type) + switch (j.type()) { - case value_t::object: + case value_t::null: + { + if (add_prefix) + { + oa->write_character(static_cast('Z')); + } + break; + } + + case value_t::boolean: + { + if (add_prefix) + oa->write_character(j.m_value.boolean + ? static_cast('T') + : static_cast('F')); + break; + } + + case value_t::number_integer: { - AllocatorType alloc; - alloc.destroy(m_value.object); - alloc.deallocate(m_value.object, 1); + write_number_with_ubjson_prefix(j.m_value.number_integer, add_prefix); break; } - case value_t::array: + case value_t::number_unsigned: { - AllocatorType alloc; - alloc.destroy(m_value.array); - alloc.deallocate(m_value.array, 1); + write_number_with_ubjson_prefix(j.m_value.number_unsigned, add_prefix); break; } - case value_t::string: + case value_t::number_float: { - AllocatorType alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); + write_number_with_ubjson_prefix(j.m_value.number_float, add_prefix); break; } - default: + case value_t::string: { - // all other types need no specific destructor + if (add_prefix) + { + oa->write_character(static_cast('S')); + } + write_number_with_ubjson_prefix(j.m_value.string->size(), true); + oa->write_characters( + reinterpret_cast(j.m_value.string->c_str()), + j.m_value.string->size()); break; } - } - } - - /// @} - - public: - /////////////////////// - // object inspection // - /////////////////////// - - /// @name object inspection - /// Functions to inspect the type of a JSON value. - /// @{ - - /*! - @brief serialization - - Serialization function for JSON values. The function tries to mimic - Python's `json.dumps()` function, and currently supports its @a indent - parameter. - @param[in] indent If indent is nonnegative, then array elements and object - members will be pretty-printed with that indent level. An indent level of - `0` will only insert newlines. `-1` (the default) selects the most compact - representation. - @param[in] indent_char The character to use for indentation of @a indent is - greate than `0`. The default is ` ` (space). + case value_t::array: + { + if (add_prefix) + { + oa->write_character(static_cast('[')); + } - @return string containing the serialization of the JSON value + bool prefix_required = true; + if (use_type and not j.m_value.array->empty()) + { + assert(use_count); + const CharType first_prefix = ubjson_prefix(j.front()); + const bool same_prefix = std::all_of(j.begin() + 1, j.end(), + [this, first_prefix](const BasicJsonType & v) + { + return ubjson_prefix(v) == first_prefix; + }); - @complexity Linear. + if (same_prefix) + { + prefix_required = false; + oa->write_character(static_cast('$')); + oa->write_character(first_prefix); + } + } - @liveexample{The following example shows the effect of different @a indent - parameters to the result of the serialization.,dump} + if (use_count) + { + oa->write_character(static_cast('#')); + write_number_with_ubjson_prefix(j.m_value.array->size(), true); + } - @see https://docs.python.org/2/library/json.html#json.dump + for (const auto& el : *j.m_value.array) + { + write_ubjson(el, use_count, use_type, prefix_required); + } - @since version 1.0.0; indentaction character added in version 3.0.0 - */ - string_t dump(const int indent = -1, const char indent_char = ' ') const - { - string_t result; - serializer s(output_adapter::create(result), indent_char); + if (not use_count) + { + oa->write_character(static_cast(']')); + } - if (indent >= 0) - { - s.dump(*this, true, static_cast(indent)); - } - else - { - s.dump(*this, false, 0); - } + break; + } - return result; - } + case value_t::object: + { + if (add_prefix) + { + oa->write_character(static_cast('{')); + } - /*! - @brief return the type of the JSON value (explicit) + bool prefix_required = true; + if (use_type and not j.m_value.object->empty()) + { + assert(use_count); + const CharType first_prefix = ubjson_prefix(j.front()); + const bool same_prefix = std::all_of(j.begin(), j.end(), + [this, first_prefix](const BasicJsonType & v) + { + return ubjson_prefix(v) == first_prefix; + }); - Return the type of the JSON value as a value from the @ref value_t - enumeration. + if (same_prefix) + { + prefix_required = false; + oa->write_character(static_cast('$')); + oa->write_character(first_prefix); + } + } - @return the type of the JSON value + if (use_count) + { + oa->write_character(static_cast('#')); + write_number_with_ubjson_prefix(j.m_value.object->size(), true); + } - @complexity Constant. + for (const auto& el : *j.m_value.object) + { + write_number_with_ubjson_prefix(el.first.size(), true); + oa->write_characters( + reinterpret_cast(el.first.c_str()), + el.first.size()); + write_ubjson(el.second, use_count, use_type, prefix_required); + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + if (not use_count) + { + oa->write_character(static_cast('}')); + } - @liveexample{The following code exemplifies `type()` for all JSON - types.,type} + break; + } - @since version 1.0.0 - */ - constexpr value_t type() const noexcept - { - return m_type; + default: + break; + } } - /*! - @brief return whether type is primitive - - This function returns true iff the JSON type is primitive (string, number, - boolean, or null). - - @return `true` if type is primitive (string, number, boolean, or null), - `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_primitive()` for all JSON - types.,is_primitive} + private: + /* + @brief write a number to output input - @sa @ref is_structured() -- returns whether JSON value is structured - @sa @ref is_null() -- returns whether JSON value is `null` - @sa @ref is_string() -- returns whether JSON value is a string - @sa @ref is_boolean() -- returns whether JSON value is a boolean - @sa @ref is_number() -- returns whether JSON value is a number + @param[in] n number of type @a NumberType + @tparam NumberType the type of the number - @since version 1.0.0 + @note This function needs to respect the system's endianess, because bytes + in CBOR, MessagePack, and UBJSON are stored in network order (big + endian) and therefore need reordering on little endian systems. */ - constexpr bool is_primitive() const noexcept + template + void write_number(const NumberType n) { - return is_null() or is_string() or is_boolean() or is_number(); - } - - /*! - @brief return whether type is structured + // step 1: write number to array of length NumberType + std::array vec; + std::memcpy(vec.data(), &n, sizeof(NumberType)); - This function returns true iff the JSON type is structured (array or - object). - - @return `true` if type is structured (array or object), `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_structured()` for all JSON - types.,is_structured} - - @sa @ref is_primitive() -- returns whether value is primitive - @sa @ref is_array() -- returns whether value is an array - @sa @ref is_object() -- returns whether value is an object + // step 2: write array to output (with possible reordering) + if (is_little_endian) + { + // reverse byte order prior to conversion if necessary + std::reverse(vec.begin(), vec.end()); + } - @since version 1.0.0 - */ - constexpr bool is_structured() const noexcept - { - return is_array() or is_object(); + oa->write_characters(vec.data(), sizeof(NumberType)); } - /*! - @brief return whether value is null - - This function returns true iff the JSON value is null. - - @return `true` if type is null, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_null()` for all JSON - types.,is_null} - - @since version 1.0.0 - */ - constexpr bool is_null() const noexcept + // UBJSON: write number (floating point) + template::value, int>::type = 0> + void write_number_with_ubjson_prefix(const NumberType n, + const bool add_prefix) { - return m_type == value_t::null; + if (add_prefix) + { + oa->write_character(get_ubjson_float_prefix(n)); + } + write_number(n); } - /*! - @brief return whether value is a boolean - - This function returns true iff the JSON value is a boolean. - - @return `true` if type is boolean, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_boolean()` for all JSON - types.,is_boolean} - - @since version 1.0.0 - */ - constexpr bool is_boolean() const noexcept + // UBJSON: write number (unsigned integer) + template::value, int>::type = 0> + void write_number_with_ubjson_prefix(const NumberType n, + const bool add_prefix) { - return m_type == value_t::boolean; + if (n <= static_cast((std::numeric_limits::max)())) + { + if (add_prefix) + { + oa->write_character(static_cast('i')); // int8 + } + write_number(static_cast(n)); + } + else if (n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('U')); // uint8 + } + write_number(static_cast(n)); + } + else if (n <= static_cast((std::numeric_limits::max)())) + { + if (add_prefix) + { + oa->write_character(static_cast('I')); // int16 + } + write_number(static_cast(n)); + } + else if (n <= static_cast((std::numeric_limits::max)())) + { + if (add_prefix) + { + oa->write_character(static_cast('l')); // int32 + } + write_number(static_cast(n)); + } + else if (n <= static_cast((std::numeric_limits::max)())) + { + if (add_prefix) + { + oa->write_character(static_cast('L')); // int64 + } + write_number(static_cast(n)); + } + else + { + JSON_THROW(out_of_range::create(407, "number overflow serializing " + std::to_string(n))); + } } - /*! - @brief return whether value is a number - - This function returns true iff the JSON value is a number. This includes - both integer and floating-point values. - - @return `true` if type is number (regardless whether integer, unsigned - integer or floating-type), `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_number()` for all JSON - types.,is_number} - - @sa @ref is_number_integer() -- check if value is an integer or unsigned - integer number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number - @sa @ref is_number_float() -- check if value is a floating-point number - - @since version 1.0.0 - */ - constexpr bool is_number() const noexcept + // UBJSON: write number (signed integer) + template::value and + not std::is_floating_point::value, int>::type = 0> + void write_number_with_ubjson_prefix(const NumberType n, + const bool add_prefix) { - return is_number_integer() or is_number_float(); + if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('i')); // int8 + } + write_number(static_cast(n)); + } + else if (static_cast((std::numeric_limits::min)()) <= n and n <= static_cast((std::numeric_limits::max)())) + { + if (add_prefix) + { + oa->write_character(static_cast('U')); // uint8 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('I')); // int16 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('l')); // int32 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('L')); // int64 + } + write_number(static_cast(n)); + } + // LCOV_EXCL_START + else + { + JSON_THROW(out_of_range::create(407, "number overflow serializing " + std::to_string(n))); + } + // LCOV_EXCL_STOP } /*! - @brief return whether value is an integer number - - This function returns true iff the JSON value is an integer or unsigned - integer number. This excludes floating-point values. + @brief determine the type prefix of container values - @return `true` if type is an integer or unsigned integer number, `false` - otherwise. + @note This function does not need to be 100% accurate when it comes to + integer limits. In case a number exceeds the limits of int64_t, + this will be detected by a later call to function + write_number_with_ubjson_prefix. Therefore, we return 'L' for any + value that does not fit the previous limits. + */ + CharType ubjson_prefix(const BasicJsonType& j) const noexcept + { + switch (j.type()) + { + case value_t::null: + return 'Z'; - @complexity Constant. + case value_t::boolean: + return j.m_value.boolean ? 'T' : 'F'; - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + case value_t::number_integer: + { + if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'i'; + } + else if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'U'; + } + else if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'I'; + } + else if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'l'; + } + else // no check and assume int64_t (see note above) + { + return 'L'; + } + } - @liveexample{The following code exemplifies `is_number_integer()` for all - JSON types.,is_number_integer} + case value_t::number_unsigned: + { + if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'i'; + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'U'; + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'I'; + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'l'; + } + else // no check and assume int64_t (see note above) + { + return 'L'; + } + } - @sa @ref is_number() -- check if value is a number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number - @sa @ref is_number_float() -- check if value is a floating-point number + case value_t::number_float: + return get_ubjson_float_prefix(j.m_value.number_float); - @since version 1.0.0 - */ - constexpr bool is_number_integer() const noexcept - { - return m_type == value_t::number_integer or m_type == value_t::number_unsigned; - } + case value_t::string: + return 'S'; - /*! - @brief return whether value is an unsigned integer number + case value_t::array: + return '['; - This function returns true iff the JSON value is an unsigned integer - number. This excludes floating-point and (signed) integer values. + case value_t::object: + return '{'; - @return `true` if type is an unsigned integer number, `false` otherwise. + default: // discarded values + return 'N'; + } + } - @complexity Constant. + static constexpr CharType get_cbor_float_prefix(float) + { + return static_cast(0xFA); // Single-Precision Float + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + static constexpr CharType get_cbor_float_prefix(double) + { + return static_cast(0xFB); // Double-Precision Float + } - @liveexample{The following code exemplifies `is_number_unsigned()` for all - JSON types.,is_number_unsigned} + static constexpr CharType get_msgpack_float_prefix(float) + { + return static_cast(0xCA); // float 32 + } - @sa @ref is_number() -- check if value is a number - @sa @ref is_number_integer() -- check if value is an integer or unsigned - integer number - @sa @ref is_number_float() -- check if value is a floating-point number + static constexpr CharType get_msgpack_float_prefix(double) + { + return static_cast(0xCB); // float 64 + } - @since version 2.0.0 - */ - constexpr bool is_number_unsigned() const noexcept + static constexpr CharType get_ubjson_float_prefix(float) { - return m_type == value_t::number_unsigned; + return 'd'; // float 32 } - /*! - @brief return whether value is a floating-point number + static constexpr CharType get_ubjson_float_prefix(double) + { + return 'D'; // float 64 + } - This function returns true iff the JSON value is a floating-point number. - This excludes integer and unsigned integer values. + private: + /// whether we can assume little endianess + const bool is_little_endian = binary_reader::little_endianess(); - @return `true` if type is a floating-point number, `false` otherwise. + /// the output + output_adapter_t oa = nullptr; +}; +} +} - @complexity Constant. +// #include - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - @liveexample{The following code exemplifies `is_number_float()` for all - JSON types.,is_number_float} +#include // reverse, remove, fill, find, none_of +#include // array +#include // assert +#include // and, or +#include // localeconv, lconv +#include // labs, isfinite, isnan, signbit +#include // size_t, ptrdiff_t +#include // uint8_t +#include // snprintf +#include // setfill +#include // next +#include // numeric_limits +#include // string +#include // stringstream +#include // is_same - @sa @ref is_number() -- check if value is number - @sa @ref is_number_integer() -- check if value is an integer number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number +// #include - @since version 1.0.0 - */ - constexpr bool is_number_float() const noexcept - { - return m_type == value_t::number_float; - } +// #include - /*! - @brief return whether value is an object - This function returns true iff the JSON value is an object. +#include // assert +#include // or, and, not +#include // signbit, isfinite +#include // intN_t, uintN_t +#include // memcpy, memmove - @return `true` if type is object, `false` otherwise. +namespace nlohmann +{ +namespace detail +{ - @complexity Constant. +/*! +@brief implements the Grisu2 algorithm for binary to decimal floating-point +conversion. - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. +This implementation is a slightly modified version of the reference +implementation which may be obtained from +http://florian.loitsch.com/publications (bench.tar.gz). - @liveexample{The following code exemplifies `is_object()` for all JSON - types.,is_object} +The code is distributed under the MIT license, Copyright (c) 2009 Florian Loitsch. - @since version 1.0.0 - */ - constexpr bool is_object() const noexcept - { - return m_type == value_t::object; - } +For a detailed description of the algorithm see: - /*! - @brief return whether value is an array +[1] Loitsch, "Printing Floating-Point Numbers Quickly and Accurately with + Integers", Proceedings of the ACM SIGPLAN 2010 Conference on Programming + Language Design and Implementation, PLDI 2010 +[2] Burger, Dybvig, "Printing Floating-Point Numbers Quickly and Accurately", + Proceedings of the ACM SIGPLAN 1996 Conference on Programming Language + Design and Implementation, PLDI 1996 +*/ +namespace dtoa_impl +{ - This function returns true iff the JSON value is an array. +template +Target reinterpret_bits(const Source source) +{ + static_assert(sizeof(Target) == sizeof(Source), "size mismatch"); - @return `true` if type is array, `false` otherwise. + Target target; + std::memcpy(&target, &source, sizeof(Source)); + return target; +} - @complexity Constant. +struct diyfp // f * 2^e +{ + static constexpr int kPrecision = 64; // = q - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + uint64_t f; + int e; - @liveexample{The following code exemplifies `is_array()` for all JSON - types.,is_array} + constexpr diyfp() noexcept : f(0), e(0) {} + constexpr diyfp(uint64_t f_, int e_) noexcept : f(f_), e(e_) {} - @since version 1.0.0 + /*! + @brief returns x - y + @pre x.e == y.e and x.f >= y.f */ - constexpr bool is_array() const noexcept + static diyfp sub(const diyfp& x, const diyfp& y) noexcept { - return m_type == value_t::array; + assert(x.e == y.e); + assert(x.f >= y.f); + + return diyfp(x.f - y.f, x.e); } /*! - @brief return whether value is a string - - This function returns true iff the JSON value is a string. - - @return `true` if type is string, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_string()` for all JSON - types.,is_string} - - @since version 1.0.0 + @brief returns x * y + @note The result is rounded. (Only the upper q bits are returned.) */ - constexpr bool is_string() const noexcept + static diyfp mul(const diyfp& x, const diyfp& y) noexcept { - return m_type == value_t::string; + static_assert(kPrecision == 64, "internal error"); + + // Computes: + // f = round((x.f * y.f) / 2^q) + // e = x.e + y.e + q + + // Emulate the 64-bit * 64-bit multiplication: + // + // p = u * v + // = (u_lo + 2^32 u_hi) (v_lo + 2^32 v_hi) + // = (u_lo v_lo ) + 2^32 ((u_lo v_hi ) + (u_hi v_lo )) + 2^64 (u_hi v_hi ) + // = (p0 ) + 2^32 ((p1 ) + (p2 )) + 2^64 (p3 ) + // = (p0_lo + 2^32 p0_hi) + 2^32 ((p1_lo + 2^32 p1_hi) + (p2_lo + 2^32 p2_hi)) + 2^64 (p3 ) + // = (p0_lo ) + 2^32 (p0_hi + p1_lo + p2_lo ) + 2^64 (p1_hi + p2_hi + p3) + // = (p0_lo ) + 2^32 (Q ) + 2^64 (H ) + // = (p0_lo ) + 2^32 (Q_lo + 2^32 Q_hi ) + 2^64 (H ) + // + // (Since Q might be larger than 2^32 - 1) + // + // = (p0_lo + 2^32 Q_lo) + 2^64 (Q_hi + H) + // + // (Q_hi + H does not overflow a 64-bit int) + // + // = p_lo + 2^64 p_hi + + const uint64_t u_lo = x.f & 0xFFFFFFFF; + const uint64_t u_hi = x.f >> 32; + const uint64_t v_lo = y.f & 0xFFFFFFFF; + const uint64_t v_hi = y.f >> 32; + + const uint64_t p0 = u_lo * v_lo; + const uint64_t p1 = u_lo * v_hi; + const uint64_t p2 = u_hi * v_lo; + const uint64_t p3 = u_hi * v_hi; + + const uint64_t p0_hi = p0 >> 32; + const uint64_t p1_lo = p1 & 0xFFFFFFFF; + const uint64_t p1_hi = p1 >> 32; + const uint64_t p2_lo = p2 & 0xFFFFFFFF; + const uint64_t p2_hi = p2 >> 32; + + uint64_t Q = p0_hi + p1_lo + p2_lo; + + // The full product might now be computed as + // + // p_hi = p3 + p2_hi + p1_hi + (Q >> 32) + // p_lo = p0_lo + (Q << 32) + // + // But in this particular case here, the full p_lo is not required. + // Effectively we only need to add the highest bit in p_lo to p_hi (and + // Q_hi + 1 does not overflow). + + Q += uint64_t{1} << (64 - 32 - 1); // round, ties up + + const uint64_t h = p3 + p2_hi + p1_hi + (Q >> 32); + + return diyfp(h, x.e + y.e + 64); } /*! - @brief return whether value is discarded - - This function returns true iff the JSON value was discarded during parsing - with a callback function (see @ref parser_callback_t). - - @note This function will always be `false` for JSON values after parsing. - That is, discarded values can only occur during parsing, but will be - removed when inside a structured value or replaced by null in other cases. - - @return `true` if type is discarded, `false` otherwise. - - @complexity Constant. + @brief normalize x such that the significand is >= 2^(q-1) + @pre x.f != 0 + */ + static diyfp normalize(diyfp x) noexcept + { + assert(x.f != 0); - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + while ((x.f >> 63) == 0) + { + x.f <<= 1; + x.e--; + } - @liveexample{The following code exemplifies `is_discarded()` for all JSON - types.,is_discarded} + return x; + } - @since version 1.0.0 + /*! + @brief normalize x such that the result has the exponent E + @pre e >= x.e and the upper e - x.e bits of x.f must be zero. */ - constexpr bool is_discarded() const noexcept + static diyfp normalize_to(const diyfp& x, const int target_exponent) noexcept { - return m_type == value_t::discarded; - } + const int delta = x.e - target_exponent; - /*! - @brief return the type of the JSON value (implicit) + assert(delta >= 0); + assert(((x.f << delta) >> delta) == x.f); - Implicitly return the type of the JSON value as a value from the @ref - value_t enumeration. + return diyfp(x.f << delta, target_exponent); + } +}; - @return the type of the JSON value +struct boundaries +{ + diyfp w; + diyfp minus; + diyfp plus; +}; - @complexity Constant. +/*! +Compute the (normalized) diyfp representing the input number 'value' and its +boundaries. - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. +@pre value must be finite and positive +*/ +template +boundaries compute_boundaries(FloatType value) +{ + assert(std::isfinite(value)); + assert(value > 0); + + // Convert the IEEE representation into a diyfp. + // + // If v is denormal: + // value = 0.F * 2^(1 - bias) = ( F) * 2^(1 - bias - (p-1)) + // If v is normalized: + // value = 1.F * 2^(E - bias) = (2^(p-1) + F) * 2^(E - bias - (p-1)) + + static_assert(std::numeric_limits::is_iec559, + "internal error: dtoa_short requires an IEEE-754 floating-point implementation"); + + constexpr int kPrecision = std::numeric_limits::digits; // = p (includes the hidden bit) + constexpr int kBias = std::numeric_limits::max_exponent - 1 + (kPrecision - 1); + constexpr int kMinExp = 1 - kBias; + constexpr uint64_t kHiddenBit = uint64_t{1} << (kPrecision - 1); // = 2^(p-1) + + using bits_type = typename std::conditional< kPrecision == 24, uint32_t, uint64_t >::type; + + const uint64_t bits = reinterpret_bits(value); + const uint64_t E = bits >> (kPrecision - 1); + const uint64_t F = bits & (kHiddenBit - 1); + + const bool is_denormal = (E == 0); + const diyfp v = is_denormal + ? diyfp(F, kMinExp) + : diyfp(F + kHiddenBit, static_cast(E) - kBias); + + // Compute the boundaries m- and m+ of the floating-point value + // v = f * 2^e. + // + // Determine v- and v+, the floating-point predecessor and successor if v, + // respectively. + // + // v- = v - 2^e if f != 2^(p-1) or e == e_min (A) + // = v - 2^(e-1) if f == 2^(p-1) and e > e_min (B) + // + // v+ = v + 2^e + // + // Let m- = (v- + v) / 2 and m+ = (v + v+) / 2. All real numbers _strictly_ + // between m- and m+ round to v, regardless of how the input rounding + // algorithm breaks ties. + // + // ---+-------------+-------------+-------------+-------------+--- (A) + // v- m- v m+ v+ + // + // -----------------+------+------+-------------+-------------+--- (B) + // v- m- v m+ v+ + + const bool lower_boundary_is_closer = (F == 0 and E > 1); + const diyfp m_plus = diyfp(2 * v.f + 1, v.e - 1); + const diyfp m_minus = lower_boundary_is_closer + ? diyfp(4 * v.f - 1, v.e - 2) // (B) + : diyfp(2 * v.f - 1, v.e - 1); // (A) + + // Determine the normalized w+ = m+. + const diyfp w_plus = diyfp::normalize(m_plus); + + // Determine w- = m- such that e_(w-) = e_(w+). + const diyfp w_minus = diyfp::normalize_to(m_minus, w_plus.e); + + return {diyfp::normalize(v), w_minus, w_plus}; +} - @liveexample{The following code exemplifies the @ref value_t operator for - all JSON types.,operator__value_t} +// Given normalized diyfp w, Grisu needs to find a (normalized) cached +// power-of-ten c, such that the exponent of the product c * w = f * 2^e lies +// within a certain range [alpha, gamma] (Definition 3.2 from [1]) +// +// alpha <= e = e_c + e_w + q <= gamma +// +// or +// +// f_c * f_w * 2^alpha <= f_c 2^(e_c) * f_w 2^(e_w) * 2^q +// <= f_c * f_w * 2^gamma +// +// Since c and w are normalized, i.e. 2^(q-1) <= f < 2^q, this implies +// +// 2^(q-1) * 2^(q-1) * 2^alpha <= c * w * 2^q < 2^q * 2^q * 2^gamma +// +// or +// +// 2^(q - 2 + alpha) <= c * w < 2^(q + gamma) +// +// The choice of (alpha,gamma) determines the size of the table and the form of +// the digit generation procedure. Using (alpha,gamma)=(-60,-32) works out well +// in practice: +// +// The idea is to cut the number c * w = f * 2^e into two parts, which can be +// processed independently: An integral part p1, and a fractional part p2: +// +// f * 2^e = ( (f div 2^-e) * 2^-e + (f mod 2^-e) ) * 2^e +// = (f div 2^-e) + (f mod 2^-e) * 2^e +// = p1 + p2 * 2^e +// +// The conversion of p1 into decimal form requires a series of divisions and +// modulos by (a power of) 10. These operations are faster for 32-bit than for +// 64-bit integers, so p1 should ideally fit into a 32-bit integer. This can be +// achieved by choosing +// +// -e >= 32 or e <= -32 := gamma +// +// In order to convert the fractional part +// +// p2 * 2^e = p2 / 2^-e = d[-1] / 10^1 + d[-2] / 10^2 + ... +// +// into decimal form, the fraction is repeatedly multiplied by 10 and the digits +// d[-i] are extracted in order: +// +// (10 * p2) div 2^-e = d[-1] +// (10 * p2) mod 2^-e = d[-2] / 10^1 + ... +// +// The multiplication by 10 must not overflow. It is sufficient to choose +// +// 10 * p2 < 16 * p2 = 2^4 * p2 <= 2^64. +// +// Since p2 = f mod 2^-e < 2^-e, +// +// -e <= 60 or e >= -60 := alpha + +constexpr int kAlpha = -60; +constexpr int kGamma = -32; + +struct cached_power // c = f * 2^e ~= 10^k +{ + uint64_t f; + int e; + int k; +}; - @since version 1.0.0 - */ - constexpr operator value_t() const noexcept - { - return m_type; - } +/*! +For a normalized diyfp w = f * 2^e, this function returns a (normalized) cached +power-of-ten c = f_c * 2^e_c, such that the exponent of the product w * c +satisfies (Definition 3.2 from [1]) - /// @} + alpha <= e_c + e + q <= gamma. +*/ +inline cached_power get_cached_power_for_binary_exponent(int e) +{ + // Now + // + // alpha <= e_c + e + q <= gamma (1) + // ==> f_c * 2^alpha <= c * 2^e * 2^q + // + // and since the c's are normalized, 2^(q-1) <= f_c, + // + // ==> 2^(q - 1 + alpha) <= c * 2^(e + q) + // ==> 2^(alpha - e - 1) <= c + // + // If c were an exakt power of ten, i.e. c = 10^k, one may determine k as + // + // k = ceil( log_10( 2^(alpha - e - 1) ) ) + // = ceil( (alpha - e - 1) * log_10(2) ) + // + // From the paper: + // "In theory the result of the procedure could be wrong since c is rounded, + // and the computation itself is approximated [...]. In practice, however, + // this simple function is sufficient." + // + // For IEEE double precision floating-point numbers converted into + // normalized diyfp's w = f * 2^e, with q = 64, + // + // e >= -1022 (min IEEE exponent) + // -52 (p - 1) + // -52 (p - 1, possibly normalize denormal IEEE numbers) + // -11 (normalize the diyfp) + // = -1137 + // + // and + // + // e <= +1023 (max IEEE exponent) + // -52 (p - 1) + // -11 (normalize the diyfp) + // = 960 + // + // This binary exponent range [-1137,960] results in a decimal exponent + // range [-307,324]. One does not need to store a cached power for each + // k in this range. For each such k it suffices to find a cached power + // such that the exponent of the product lies in [alpha,gamma]. + // This implies that the difference of the decimal exponents of adjacent + // table entries must be less than or equal to + // + // floor( (gamma - alpha) * log_10(2) ) = 8. + // + // (A smaller distance gamma-alpha would require a larger table.) + + // NB: + // Actually this function returns c, such that -60 <= e_c + e + 64 <= -34. + + constexpr int kCachedPowersSize = 79; + constexpr int kCachedPowersMinDecExp = -300; + constexpr int kCachedPowersDecStep = 8; + + static constexpr cached_power kCachedPowers[] = + { + { 0xAB70FE17C79AC6CA, -1060, -300 }, + { 0xFF77B1FCBEBCDC4F, -1034, -292 }, + { 0xBE5691EF416BD60C, -1007, -284 }, + { 0x8DD01FAD907FFC3C, -980, -276 }, + { 0xD3515C2831559A83, -954, -268 }, + { 0x9D71AC8FADA6C9B5, -927, -260 }, + { 0xEA9C227723EE8BCB, -901, -252 }, + { 0xAECC49914078536D, -874, -244 }, + { 0x823C12795DB6CE57, -847, -236 }, + { 0xC21094364DFB5637, -821, -228 }, + { 0x9096EA6F3848984F, -794, -220 }, + { 0xD77485CB25823AC7, -768, -212 }, + { 0xA086CFCD97BF97F4, -741, -204 }, + { 0xEF340A98172AACE5, -715, -196 }, + { 0xB23867FB2A35B28E, -688, -188 }, + { 0x84C8D4DFD2C63F3B, -661, -180 }, + { 0xC5DD44271AD3CDBA, -635, -172 }, + { 0x936B9FCEBB25C996, -608, -164 }, + { 0xDBAC6C247D62A584, -582, -156 }, + { 0xA3AB66580D5FDAF6, -555, -148 }, + { 0xF3E2F893DEC3F126, -529, -140 }, + { 0xB5B5ADA8AAFF80B8, -502, -132 }, + { 0x87625F056C7C4A8B, -475, -124 }, + { 0xC9BCFF6034C13053, -449, -116 }, + { 0x964E858C91BA2655, -422, -108 }, + { 0xDFF9772470297EBD, -396, -100 }, + { 0xA6DFBD9FB8E5B88F, -369, -92 }, + { 0xF8A95FCF88747D94, -343, -84 }, + { 0xB94470938FA89BCF, -316, -76 }, + { 0x8A08F0F8BF0F156B, -289, -68 }, + { 0xCDB02555653131B6, -263, -60 }, + { 0x993FE2C6D07B7FAC, -236, -52 }, + { 0xE45C10C42A2B3B06, -210, -44 }, + { 0xAA242499697392D3, -183, -36 }, + { 0xFD87B5F28300CA0E, -157, -28 }, + { 0xBCE5086492111AEB, -130, -20 }, + { 0x8CBCCC096F5088CC, -103, -12 }, + { 0xD1B71758E219652C, -77, -4 }, + { 0x9C40000000000000, -50, 4 }, + { 0xE8D4A51000000000, -24, 12 }, + { 0xAD78EBC5AC620000, 3, 20 }, + { 0x813F3978F8940984, 30, 28 }, + { 0xC097CE7BC90715B3, 56, 36 }, + { 0x8F7E32CE7BEA5C70, 83, 44 }, + { 0xD5D238A4ABE98068, 109, 52 }, + { 0x9F4F2726179A2245, 136, 60 }, + { 0xED63A231D4C4FB27, 162, 68 }, + { 0xB0DE65388CC8ADA8, 189, 76 }, + { 0x83C7088E1AAB65DB, 216, 84 }, + { 0xC45D1DF942711D9A, 242, 92 }, + { 0x924D692CA61BE758, 269, 100 }, + { 0xDA01EE641A708DEA, 295, 108 }, + { 0xA26DA3999AEF774A, 322, 116 }, + { 0xF209787BB47D6B85, 348, 124 }, + { 0xB454E4A179DD1877, 375, 132 }, + { 0x865B86925B9BC5C2, 402, 140 }, + { 0xC83553C5C8965D3D, 428, 148 }, + { 0x952AB45CFA97A0B3, 455, 156 }, + { 0xDE469FBD99A05FE3, 481, 164 }, + { 0xA59BC234DB398C25, 508, 172 }, + { 0xF6C69A72A3989F5C, 534, 180 }, + { 0xB7DCBF5354E9BECE, 561, 188 }, + { 0x88FCF317F22241E2, 588, 196 }, + { 0xCC20CE9BD35C78A5, 614, 204 }, + { 0x98165AF37B2153DF, 641, 212 }, + { 0xE2A0B5DC971F303A, 667, 220 }, + { 0xA8D9D1535CE3B396, 694, 228 }, + { 0xFB9B7CD9A4A7443C, 720, 236 }, + { 0xBB764C4CA7A44410, 747, 244 }, + { 0x8BAB8EEFB6409C1A, 774, 252 }, + { 0xD01FEF10A657842C, 800, 260 }, + { 0x9B10A4E5E9913129, 827, 268 }, + { 0xE7109BFBA19C0C9D, 853, 276 }, + { 0xAC2820D9623BF429, 880, 284 }, + { 0x80444B5E7AA7CF85, 907, 292 }, + { 0xBF21E44003ACDD2D, 933, 300 }, + { 0x8E679C2F5E44FF8F, 960, 308 }, + { 0xD433179D9C8CB841, 986, 316 }, + { 0x9E19DB92B4E31BA9, 1013, 324 }, + }; - private: - ////////////////// - // value access // - ////////////////// + // This computation gives exactly the same results for k as + // k = ceil((kAlpha - e - 1) * 0.30102999566398114) + // for |e| <= 1500, but doesn't require floating-point operations. + // NB: log_10(2) ~= 78913 / 2^18 + assert(e >= -1500); + assert(e <= 1500); + const int f = kAlpha - e - 1; + const int k = (f * 78913) / (1 << 18) + (f > 0); + + const int index = (-kCachedPowersMinDecExp + k + (kCachedPowersDecStep - 1)) / kCachedPowersDecStep; + assert(index >= 0); + assert(index < kCachedPowersSize); + static_cast(kCachedPowersSize); // Fix warning. + + const cached_power cached = kCachedPowers[index]; + assert(kAlpha <= cached.e + e + 64); + assert(kGamma >= cached.e + e + 64); + + return cached; +} - /// get a boolean (explicit) - boolean_t get_impl(boolean_t* /*unused*/) const +/*! +For n != 0, returns k, such that pow10 := 10^(k-1) <= n < 10^k. +For n == 0, returns 1 and sets pow10 := 1. +*/ +inline int find_largest_pow10(const uint32_t n, uint32_t& pow10) +{ + // LCOV_EXCL_START + if (n >= 1000000000) { - if (is_boolean()) - { - return m_value.boolean; - } - - JSON_THROW(type_error::create(302, "type must be boolean, but is " + type_name())); + pow10 = 1000000000; + return 10; } - - /// get a pointer to the value (object) - object_t* get_impl_ptr(object_t* /*unused*/) noexcept + // LCOV_EXCL_STOP + else if (n >= 100000000) { - return is_object() ? m_value.object : nullptr; + pow10 = 100000000; + return 9; + } + else if (n >= 10000000) + { + pow10 = 10000000; + return 8; + } + else if (n >= 1000000) + { + pow10 = 1000000; + return 7; + } + else if (n >= 100000) + { + pow10 = 100000; + return 6; + } + else if (n >= 10000) + { + pow10 = 10000; + return 5; + } + else if (n >= 1000) + { + pow10 = 1000; + return 4; + } + else if (n >= 100) + { + pow10 = 100; + return 3; + } + else if (n >= 10) + { + pow10 = 10; + return 2; + } + else + { + pow10 = 1; + return 1; } +} - /// get a pointer to the value (object) - constexpr const object_t* get_impl_ptr(const object_t* /*unused*/) const noexcept +inline void grisu2_round(char* buf, int len, uint64_t dist, uint64_t delta, + uint64_t rest, uint64_t ten_k) +{ + assert(len >= 1); + assert(dist <= delta); + assert(rest <= delta); + assert(ten_k > 0); + + // <--------------------------- delta ----> + // <---- dist ---------> + // --------------[------------------+-------------------]-------------- + // M- w M+ + // + // ten_k + // <------> + // <---- rest ----> + // --------------[------------------+----+--------------]-------------- + // w V + // = buf * 10^k + // + // ten_k represents a unit-in-the-last-place in the decimal representation + // stored in buf. + // Decrement buf by ten_k while this takes buf closer to w. + + // The tests are written in this order to avoid overflow in unsigned + // integer arithmetic. + + while (rest < dist + and delta - rest >= ten_k + and (rest + ten_k < dist or dist - rest > rest + ten_k - dist)) { - return is_object() ? m_value.object : nullptr; + assert(buf[len - 1] != '0'); + buf[len - 1]--; + rest += ten_k; } +} - /// get a pointer to the value (array) - array_t* get_impl_ptr(array_t* /*unused*/) noexcept +/*! +Generates V = buffer * 10^decimal_exponent, such that M- <= V <= M+. +M- and M+ must be normalized and share the same exponent -60 <= e <= -32. +*/ +inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent, + diyfp M_minus, diyfp w, diyfp M_plus) +{ + static_assert(kAlpha >= -60, "internal error"); + static_assert(kGamma <= -32, "internal error"); + + // Generates the digits (and the exponent) of a decimal floating-point + // number V = buffer * 10^decimal_exponent in the range [M-, M+]. The diyfp's + // w, M- and M+ share the same exponent e, which satisfies alpha <= e <= gamma. + // + // <--------------------------- delta ----> + // <---- dist ---------> + // --------------[------------------+-------------------]-------------- + // M- w M+ + // + // Grisu2 generates the digits of M+ from left to right and stops as soon as + // V is in [M-,M+]. + + assert(M_plus.e >= kAlpha); + assert(M_plus.e <= kGamma); + + uint64_t delta = diyfp::sub(M_plus, M_minus).f; // (significand of (M+ - M-), implicit exponent is e) + uint64_t dist = diyfp::sub(M_plus, w ).f; // (significand of (M+ - w ), implicit exponent is e) + + // Split M+ = f * 2^e into two parts p1 and p2 (note: e < 0): + // + // M+ = f * 2^e + // = ((f div 2^-e) * 2^-e + (f mod 2^-e)) * 2^e + // = ((p1 ) * 2^-e + (p2 )) * 2^e + // = p1 + p2 * 2^e + + const diyfp one(uint64_t{1} << -M_plus.e, M_plus.e); + + uint32_t p1 = static_cast(M_plus.f >> -one.e); // p1 = f div 2^-e (Since -e >= 32, p1 fits into a 32-bit int.) + uint64_t p2 = M_plus.f & (one.f - 1); // p2 = f mod 2^-e + + // 1) + // + // Generate the digits of the integral part p1 = d[n-1]...d[1]d[0] + + assert(p1 > 0); + + uint32_t pow10; + const int k = find_largest_pow10(p1, pow10); + + // 10^(k-1) <= p1 < 10^k, pow10 = 10^(k-1) + // + // p1 = (p1 div 10^(k-1)) * 10^(k-1) + (p1 mod 10^(k-1)) + // = (d[k-1] ) * 10^(k-1) + (p1 mod 10^(k-1)) + // + // M+ = p1 + p2 * 2^e + // = d[k-1] * 10^(k-1) + (p1 mod 10^(k-1)) + p2 * 2^e + // = d[k-1] * 10^(k-1) + ((p1 mod 10^(k-1)) * 2^-e + p2) * 2^e + // = d[k-1] * 10^(k-1) + ( rest) * 2^e + // + // Now generate the digits d[n] of p1 from left to right (n = k-1,...,0) + // + // p1 = d[k-1]...d[n] * 10^n + d[n-1]...d[0] + // + // but stop as soon as + // + // rest * 2^e = (d[n-1]...d[0] * 2^-e + p2) * 2^e <= delta * 2^e + + int n = k; + while (n > 0) { - return is_array() ? m_value.array : nullptr; + // Invariants: + // M+ = buffer * 10^n + (p1 + p2 * 2^e) (buffer = 0 for n = k) + // pow10 = 10^(n-1) <= p1 < 10^n + // + const uint32_t d = p1 / pow10; // d = p1 div 10^(n-1) + const uint32_t r = p1 % pow10; // r = p1 mod 10^(n-1) + // + // M+ = buffer * 10^n + (d * 10^(n-1) + r) + p2 * 2^e + // = (buffer * 10 + d) * 10^(n-1) + (r + p2 * 2^e) + // + assert(d <= 9); + buffer[length++] = static_cast('0' + d); // buffer := buffer * 10 + d + // + // M+ = buffer * 10^(n-1) + (r + p2 * 2^e) + // + p1 = r; + n--; + // + // M+ = buffer * 10^n + (p1 + p2 * 2^e) + // pow10 = 10^n + // + + // Now check if enough digits have been generated. + // Compute + // + // p1 + p2 * 2^e = (p1 * 2^-e + p2) * 2^e = rest * 2^e + // + // Note: + // Since rest and delta share the same exponent e, it suffices to + // compare the significands. + const uint64_t rest = (uint64_t{p1} << -one.e) + p2; + if (rest <= delta) + { + // V = buffer * 10^n, with M- <= V <= M+. + + decimal_exponent += n; + + // We may now just stop. But instead look if the buffer could be + // decremented to bring V closer to w. + // + // pow10 = 10^n is now 1 ulp in the decimal representation V. + // The rounding procedure works with diyfp's with an implicit + // exponent of e. + // + // 10^n = (10^n * 2^-e) * 2^e = ulp * 2^e + // + const uint64_t ten_n = uint64_t{pow10} << -one.e; + grisu2_round(buffer, length, dist, delta, rest, ten_n); + + return; + } + + pow10 /= 10; + // + // pow10 = 10^(n-1) <= p1 < 10^n + // Invariants restored. } - /// get a pointer to the value (array) - constexpr const array_t* get_impl_ptr(const array_t* /*unused*/) const noexcept + // 2) + // + // The digits of the integral part have been generated: + // + // M+ = d[k-1]...d[1]d[0] + p2 * 2^e + // = buffer + p2 * 2^e + // + // Now generate the digits of the fractional part p2 * 2^e. + // + // Note: + // No decimal point is generated: the exponent is adjusted instead. + // + // p2 actually represents the fraction + // + // p2 * 2^e + // = p2 / 2^-e + // = d[-1] / 10^1 + d[-2] / 10^2 + ... + // + // Now generate the digits d[-m] of p1 from left to right (m = 1,2,...) + // + // p2 * 2^e = d[-1]d[-2]...d[-m] * 10^-m + // + 10^-m * (d[-m-1] / 10^1 + d[-m-2] / 10^2 + ...) + // + // using + // + // 10^m * p2 = ((10^m * p2) div 2^-e) * 2^-e + ((10^m * p2) mod 2^-e) + // = ( d) * 2^-e + ( r) + // + // or + // 10^m * p2 * 2^e = d + r * 2^e + // + // i.e. + // + // M+ = buffer + p2 * 2^e + // = buffer + 10^-m * (d + r * 2^e) + // = (buffer * 10^m + d) * 10^-m + 10^-m * r * 2^e + // + // and stop as soon as 10^-m * r * 2^e <= delta * 2^e + + assert(p2 > delta); + + int m = 0; + for (;;) { - return is_array() ? m_value.array : nullptr; + // Invariant: + // M+ = buffer * 10^-m + 10^-m * (d[-m-1] / 10 + d[-m-2] / 10^2 + ...) * 2^e + // = buffer * 10^-m + 10^-m * (p2 ) * 2^e + // = buffer * 10^-m + 10^-m * (1/10 * (10 * p2) ) * 2^e + // = buffer * 10^-m + 10^-m * (1/10 * ((10*p2 div 2^-e) * 2^-e + (10*p2 mod 2^-e)) * 2^e + // + assert(p2 <= UINT64_MAX / 10); + p2 *= 10; + const uint64_t d = p2 >> -one.e; // d = (10 * p2) div 2^-e + const uint64_t r = p2 & (one.f - 1); // r = (10 * p2) mod 2^-e + // + // M+ = buffer * 10^-m + 10^-m * (1/10 * (d * 2^-e + r) * 2^e + // = buffer * 10^-m + 10^-m * (1/10 * (d + r * 2^e)) + // = (buffer * 10 + d) * 10^(-m-1) + 10^(-m-1) * r * 2^e + // + assert(d <= 9); + buffer[length++] = static_cast('0' + d); // buffer := buffer * 10 + d + // + // M+ = buffer * 10^(-m-1) + 10^(-m-1) * r * 2^e + // + p2 = r; + m++; + // + // M+ = buffer * 10^-m + 10^-m * p2 * 2^e + // Invariant restored. + + // Check if enough digits have been generated. + // + // 10^-m * p2 * 2^e <= delta * 2^e + // p2 * 2^e <= 10^m * delta * 2^e + // p2 <= 10^m * delta + delta *= 10; + dist *= 10; + if (p2 <= delta) + { + break; + } } - /// get a pointer to the value (string) - string_t* get_impl_ptr(string_t* /*unused*/) noexcept - { - return is_string() ? m_value.string : nullptr; - } + // V = buffer * 10^-m, with M- <= V <= M+. + + decimal_exponent -= m; + + // 1 ulp in the decimal representation is now 10^-m. + // Since delta and dist are now scaled by 10^m, we need to do the + // same with ulp in order to keep the units in sync. + // + // 10^m * 10^-m = 1 = 2^-e * 2^e = ten_m * 2^e + // + const uint64_t ten_m = one.f; + grisu2_round(buffer, length, dist, delta, p2, ten_m); + + // By construction this algorithm generates the shortest possible decimal + // number (Loitsch, Theorem 6.2) which rounds back to w. + // For an input number of precision p, at least + // + // N = 1 + ceil(p * log_10(2)) + // + // decimal digits are sufficient to identify all binary floating-point + // numbers (Matula, "In-and-Out conversions"). + // This implies that the algorithm does not produce more than N decimal + // digits. + // + // N = 17 for p = 53 (IEEE double precision) + // N = 9 for p = 24 (IEEE single precision) +} - /// get a pointer to the value (string) - constexpr const string_t* get_impl_ptr(const string_t* /*unused*/) const noexcept +/*! +v = buf * 10^decimal_exponent +len is the length of the buffer (number of decimal digits) +The buffer must be large enough, i.e. >= max_digits10. +*/ +inline void grisu2(char* buf, int& len, int& decimal_exponent, + diyfp m_minus, diyfp v, diyfp m_plus) +{ + assert(m_plus.e == m_minus.e); + assert(m_plus.e == v.e); + + // --------(-----------------------+-----------------------)-------- (A) + // m- v m+ + // + // --------------------(-----------+-----------------------)-------- (B) + // m- v m+ + // + // First scale v (and m- and m+) such that the exponent is in the range + // [alpha, gamma]. + + const cached_power cached = get_cached_power_for_binary_exponent(m_plus.e); + + const diyfp c_minus_k(cached.f, cached.e); // = c ~= 10^-k + + // The exponent of the products is = v.e + c_minus_k.e + q and is in the range [alpha,gamma] + const diyfp w = diyfp::mul(v, c_minus_k); + const diyfp w_minus = diyfp::mul(m_minus, c_minus_k); + const diyfp w_plus = diyfp::mul(m_plus, c_minus_k); + + // ----(---+---)---------------(---+---)---------------(---+---)---- + // w- w w+ + // = c*m- = c*v = c*m+ + // + // diyfp::mul rounds its result and c_minus_k is approximated too. w, w- and + // w+ are now off by a small amount. + // In fact: + // + // w - v * 10^k < 1 ulp + // + // To account for this inaccuracy, add resp. subtract 1 ulp. + // + // --------+---[---------------(---+---)---------------]---+-------- + // w- M- w M+ w+ + // + // Now any number in [M-, M+] (bounds included) will round to w when input, + // regardless of how the input rounding algorithm breaks ties. + // + // And digit_gen generates the shortest possible such number in [M-, M+]. + // Note that this does not mean that Grisu2 always generates the shortest + // possible number in the interval (m-, m+). + const diyfp M_minus(w_minus.f + 1, w_minus.e); + const diyfp M_plus (w_plus.f - 1, w_plus.e ); + + decimal_exponent = -cached.k; // = -(-k) = k + + grisu2_digit_gen(buf, len, decimal_exponent, M_minus, w, M_plus); +} + +/*! +v = buf * 10^decimal_exponent +len is the length of the buffer (number of decimal digits) +The buffer must be large enough, i.e. >= max_digits10. +*/ +template +void grisu2(char* buf, int& len, int& decimal_exponent, FloatType value) +{ + static_assert(diyfp::kPrecision >= std::numeric_limits::digits + 3, + "internal error: not enough precision"); + + assert(std::isfinite(value)); + assert(value > 0); + + // If the neighbors (and boundaries) of 'value' are always computed for double-precision + // numbers, all float's can be recovered using strtod (and strtof). However, the resulting + // decimal representations are not exactly "short". + // + // The documentation for 'std::to_chars' (http://en.cppreference.com/w/cpp/utility/to_chars) + // says "value is converted to a string as if by std::sprintf in the default ("C") locale" + // and since sprintf promotes float's to double's, I think this is exactly what 'std::to_chars' + // does. + // On the other hand, the documentation for 'std::to_chars' requires that "parsing the + // representation using the corresponding std::from_chars function recovers value exactly". That + // indicates that single precision floating-point numbers should be recovered using + // 'std::strtof'. + // + // NB: If the neighbors are computed for single-precision numbers, there is a single float + // (7.0385307e-26f) which can't be recovered using strtod. The resulting double precision + // value is off by 1 ulp. +#if 0 + const boundaries w = compute_boundaries(static_cast(value)); +#else + const boundaries w = compute_boundaries(value); +#endif + + grisu2(buf, len, decimal_exponent, w.minus, w.w, w.plus); +} + +/*! +@brief appends a decimal representation of e to buf +@return a pointer to the element following the exponent. +@pre -1000 < e < 1000 +*/ +inline char* append_exponent(char* buf, int e) +{ + assert(e > -1000); + assert(e < 1000); + + if (e < 0) { - return is_string() ? m_value.string : nullptr; + e = -e; + *buf++ = '-'; } - - /// get a pointer to the value (boolean) - boolean_t* get_impl_ptr(boolean_t* /*unused*/) noexcept + else { - return is_boolean() ? &m_value.boolean : nullptr; + *buf++ = '+'; } - /// get a pointer to the value (boolean) - constexpr const boolean_t* get_impl_ptr(const boolean_t* /*unused*/) const noexcept + uint32_t k = static_cast(e); + if (k < 10) { - return is_boolean() ? &m_value.boolean : nullptr; + // Always print at least two digits in the exponent. + // This is for compatibility with printf("%g"). + *buf++ = '0'; + *buf++ = static_cast('0' + k); } - - /// get a pointer to the value (integer number) - number_integer_t* get_impl_ptr(number_integer_t* /*unused*/) noexcept + else if (k < 100) { - return is_number_integer() ? &m_value.number_integer : nullptr; + *buf++ = static_cast('0' + k / 10); + k %= 10; + *buf++ = static_cast('0' + k); } - - /// get a pointer to the value (integer number) - constexpr const number_integer_t* get_impl_ptr(const number_integer_t* /*unused*/) const noexcept + else { - return is_number_integer() ? &m_value.number_integer : nullptr; + *buf++ = static_cast('0' + k / 100); + k %= 100; + *buf++ = static_cast('0' + k / 10); + k %= 10; + *buf++ = static_cast('0' + k); } - /// get a pointer to the value (unsigned number) - number_unsigned_t* get_impl_ptr(number_unsigned_t* /*unused*/) noexcept + return buf; +} + +/*! +@brief prettify v = buf * 10^decimal_exponent + +If v is in the range [10^min_exp, 10^max_exp) it will be printed in fixed-point +notation. Otherwise it will be printed in exponential notation. + +@pre min_exp < 0 +@pre max_exp > 0 +*/ +inline char* format_buffer(char* buf, int len, int decimal_exponent, + int min_exp, int max_exp) +{ + assert(min_exp < 0); + assert(max_exp > 0); + + const int k = len; + const int n = len + decimal_exponent; + + // v = buf * 10^(n-k) + // k is the length of the buffer (number of decimal digits) + // n is the position of the decimal point relative to the start of the buffer. + + if (k <= n and n <= max_exp) { - return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + // digits[000] + // len <= max_exp + 2 + + std::memset(buf + k, '0', static_cast(n - k)); + // Make it look like a floating-point number (#362, #378) + buf[n + 0] = '.'; + buf[n + 1] = '0'; + return buf + (n + 2); } - /// get a pointer to the value (unsigned number) - constexpr const number_unsigned_t* get_impl_ptr(const number_unsigned_t* /*unused*/) const noexcept + if (0 < n and n <= max_exp) { - return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + // dig.its + // len <= max_digits10 + 1 + + assert(k > n); + + std::memmove(buf + (n + 1), buf + n, static_cast(k - n)); + buf[n] = '.'; + return buf + (k + 1); } - /// get a pointer to the value (floating-point number) - number_float_t* get_impl_ptr(number_float_t* /*unused*/) noexcept + if (min_exp < n and n <= 0) { - return is_number_float() ? &m_value.number_float : nullptr; + // 0.[000]digits + // len <= 2 + (-min_exp - 1) + max_digits10 + + std::memmove(buf + (2 + -n), buf, static_cast(k)); + buf[0] = '0'; + buf[1] = '.'; + std::memset(buf + 2, '0', static_cast(-n)); + return buf + (2 + (-n) + k); } - /// get a pointer to the value (floating-point number) - constexpr const number_float_t* get_impl_ptr(const number_float_t* /*unused*/) const noexcept + if (k == 1) { - return is_number_float() ? &m_value.number_float : nullptr; + // dE+123 + // len <= 1 + 5 + + buf += 1; } + else + { + // d.igitsE+123 + // len <= max_digits10 + 1 + 5 - /*! - @brief helper function to implement get_ref() + std::memmove(buf + 2, buf + 1, static_cast(k - 1)); + buf[1] = '.'; + buf += 1 + k; + } - This funcion helps to implement get_ref() without code duplication for - const and non-const overloads + *buf++ = 'e'; + return append_exponent(buf, n - 1); +} - @tparam ThisType will be deduced as `basic_json` or `const basic_json` +} // namespace dtoa_impl - @throw type_error.303 if ReferenceType does not match underlying value - type of the current JSON - */ - template - static ReferenceType get_ref_impl(ThisType& obj) - { - // helper type - using PointerType = typename std::add_pointer::type; +/*! +@brief generates a decimal representation of the floating-point number value in [first, last). - // delegate the call to get_ptr<>() - auto ptr = obj.template get_ptr(); +The format of the resulting decimal representation is similar to printf's %g +format. Returns an iterator pointing past-the-end of the decimal representation. - if (ptr != nullptr) - { - return *ptr; - } +@note The input number must be finite, i.e. NaN's and Inf's are not supported. +@note The buffer must be large enough. +@note The result is NOT null-terminated. +*/ +template +char* to_chars(char* first, char* last, FloatType value) +{ + static_cast(last); // maybe unused - fix warning + assert(std::isfinite(value)); - JSON_THROW(type_error::create(303, "incompatible ReferenceType for get_ref, actual type is " + obj.type_name())); + // Use signbit(value) instead of (value < 0) since signbit works for -0. + if (std::signbit(value)) + { + value = -value; + *first++ = '-'; } - public: - /// @name value access - /// Direct access to the stored value of a JSON value. - /// @{ + if (value == 0) // +-0 + { + *first++ = '0'; + // Make it look like a floating-point number (#362, #378) + *first++ = '.'; + *first++ = '0'; + return first; + } - /*! - @brief get special-case overload + assert(last - first >= std::numeric_limits::max_digits10); - This overloads avoids a lot of template boilerplate, it can be seen as the - identity method + // Compute v = buffer * 10^decimal_exponent. + // The decimal digits are stored in the buffer, which needs to be interpreted + // as an unsigned decimal integer. + // len is the length of the buffer, i.e. the number of decimal digits. + int len = 0; + int decimal_exponent = 0; + dtoa_impl::grisu2(first, len, decimal_exponent, value); - @tparam BasicJsonType == @ref basic_json + assert(len <= std::numeric_limits::max_digits10); - @return a copy of *this + // Format the buffer like printf("%.*g", prec, value) + constexpr int kMinExp = -4; + // Use digits10 here to increase compatibility with version 2. + constexpr int kMaxExp = std::numeric_limits::digits10; - @complexity Constant. + assert(last - first >= kMaxExp + 2); + assert(last - first >= 2 + (-kMinExp - 1) + std::numeric_limits::max_digits10); + assert(last - first >= std::numeric_limits::max_digits10 + 6); - @since version 2.1.0 - */ - template < - typename BasicJsonType, - detail::enable_if_t::type, - basic_json_t>::value, - int> = 0 > - basic_json get() const - { - return *this; - } + return dtoa_impl::format_buffer(first, len, decimal_exponent, kMinExp, kMaxExp); +} - /*! - @brief get a value (explicit) +} // namespace detail +} // namespace nlohmann - Explicit type conversion between the JSON value and a compatible value - which is [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) - and [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). - The value is converted by calling the @ref json_serializer - `from_json()` method. +// #include - The function is equivalent to executing - @code {.cpp} - ValueType ret; - JSONSerializer::from_json(*this, ret); - return ret; - @endcode +// #include - This overloads is chosen if: - - @a ValueType is not @ref basic_json, - - @ref json_serializer has a `from_json()` method of the form - `void from_json(const basic_json&, ValueType&)`, and - - @ref json_serializer does not have a `from_json()` method of - the form `ValueType from_json(const basic_json&)` +// #include - @tparam ValueTypeCV the provided value type - @tparam ValueType the returned value type +// #include - @return copy of the JSON value, converted to @a ValueType - @throw what @ref json_serializer `from_json()` method throws +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// serialization // +/////////////////// - @liveexample{The example below shows several conversions from JSON values - to other types. There a few things to note: (1) Floating-point numbers can - be converted to integers\, (2) A JSON array can be converted to a standard - `std::vector`\, (3) A JSON object can be converted to C++ - associative containers such as `std::unordered_map`.,get__ValueType_const} +template +class serializer +{ + using string_t = typename BasicJsonType::string_t; + using number_float_t = typename BasicJsonType::number_float_t; + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + static constexpr uint8_t UTF8_ACCEPT = 0; + static constexpr uint8_t UTF8_REJECT = 1; - @since version 2.1.0 + public: + /*! + @param[in] s output stream to serialize to + @param[in] ichar indentation character to use */ - template < - typename ValueTypeCV, - typename ValueType = detail::uncvref_t, - detail::enable_if_t < - not std::is_same::value and - detail::has_from_json::value and - not detail::has_non_default_from_json::value, - int > = 0 > - ValueType get() const noexcept(noexcept( - JSONSerializer::from_json(std::declval(), std::declval()))) - { - // we cannot static_assert on ValueTypeCV being non-const, because - // there is support for get(), which is why we - // still need the uncvref - static_assert(not std::is_reference::value, - "get() cannot be used with reference types, you might want to use get_ref()"); - static_assert(std::is_default_constructible::value, - "types must be DefaultConstructible when used with get()"); + serializer(output_adapter_t s, const char ichar) + : o(std::move(s)), loc(std::localeconv()), + thousands_sep(loc->thousands_sep == nullptr ? '\0' : * (loc->thousands_sep)), + decimal_point(loc->decimal_point == nullptr ? '\0' : * (loc->decimal_point)), + indent_char(ichar), indent_string(512, indent_char) + {} - ValueType ret; - JSONSerializer::from_json(*this, ret); - return ret; - } + // delete because of pointer members + serializer(const serializer&) = delete; + serializer& operator=(const serializer&) = delete; /*! - @brief get a value (explicit); special case + @brief internal implementation of the serialization function - Explicit type conversion between the JSON value and a compatible value - which is **not** [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) - and **not** [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). - The value is converted by calling the @ref json_serializer - `from_json()` method. + This function is called by the public member function dump and organizes + the serialization internally. The indentation level is propagated as + additional parameter. In case of arrays and objects, the function is + called recursively. - The function is equivalent to executing - @code {.cpp} - return JSONSerializer::from_json(*this); - @endcode + - strings and object keys are escaped using `escape_string()` + - integer numbers are converted implicitly via `operator<<` + - floating-point numbers are converted to a string using `"%g"` format - This overloads is chosen if: - - @a ValueType is not @ref basic_json and - - @ref json_serializer has a `from_json()` method of the form - `ValueType from_json(const basic_json&)` + @param[in] val value to serialize + @param[in] pretty_print whether the output shall be pretty-printed + @param[in] indent_step the indent level + @param[in] current_indent the current indent level (only used internally) + */ + void dump(const BasicJsonType& val, const bool pretty_print, + const bool ensure_ascii, + const unsigned int indent_step, + const unsigned int current_indent = 0) + { + switch (val.m_type) + { + case value_t::object: + { + if (val.m_value.object->empty()) + { + o->write_characters("{}", 2); + return; + } - @note If @ref json_serializer has both overloads of - `from_json()`, this one is chosen. + if (pretty_print) + { + o->write_characters("{\n", 2); - @tparam ValueTypeCV the provided value type - @tparam ValueType the returned value type + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (JSON_UNLIKELY(indent_string.size() < new_indent)) + { + indent_string.resize(indent_string.size() * 2, ' '); + } - @return copy of the JSON value, converted to @a ValueType + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\": ", 3); + dump(i->second, true, ensure_ascii, indent_step, new_indent); + o->write_characters(",\n", 2); + } - @throw what @ref json_serializer `from_json()` method throws + // last element + assert(i != val.m_value.object->cend()); + assert(std::next(i) == val.m_value.object->cend()); + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\": ", 3); + dump(i->second, true, ensure_ascii, indent_step, new_indent); - @since version 2.1.0 - */ - template < - typename ValueTypeCV, - typename ValueType = detail::uncvref_t, - detail::enable_if_t::value and - detail::has_non_default_from_json::value, int> = 0 > - ValueType get() const noexcept(noexcept( - JSONSerializer::from_json(std::declval()))) - { - static_assert(not std::is_reference::value, - "get() cannot be used with reference types, you might want to use get_ref()"); - return JSONSerializer::from_json(*this); - } + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character('}'); + } + else + { + o->write_character('{'); - /*! - @brief get a pointer value (explicit) + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\":", 2); + dump(i->second, false, ensure_ascii, indent_step, current_indent); + o->write_character(','); + } - Explicit pointer access to the internally stored JSON value. No copies are - made. + // last element + assert(i != val.m_value.object->cend()); + assert(std::next(i) == val.m_value.object->cend()); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\":", 2); + dump(i->second, false, ensure_ascii, indent_step, current_indent); - @warning The pointer becomes invalid if the underlying JSON object - changes. + o->write_character('}'); + } - @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref - object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, - @ref number_unsigned_t, or @ref number_float_t. + return; + } - @return pointer to the internally stored JSON value if the requested - pointer type @a PointerType fits to the JSON value; `nullptr` otherwise + case value_t::array: + { + if (val.m_value.array->empty()) + { + o->write_characters("[]", 2); + return; + } - @complexity Constant. + if (pretty_print) + { + o->write_characters("[\n", 2); - @liveexample{The example below shows how pointers to internal values of a - JSON value can be requested. Note that no type conversions are made and a - `nullptr` is returned if the value and the requested pointer type does not - match.,get__PointerType} + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (JSON_UNLIKELY(indent_string.size() < new_indent)) + { + indent_string.resize(indent_string.size() * 2, ' '); + } + + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + dump(*i, true, ensure_ascii, indent_step, new_indent); + o->write_characters(",\n", 2); + } - @sa @ref get_ptr() for explicit pointer-member access + // last element + assert(not val.m_value.array->empty()); + o->write_characters(indent_string.c_str(), new_indent); + dump(val.m_value.array->back(), true, ensure_ascii, indent_step, new_indent); - @since version 1.0.0 - */ - template::value, int>::type = 0> - PointerType get() noexcept - { - // delegate the call to get_ptr - return get_ptr(); - } + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character(']'); + } + else + { + o->write_character('['); - /*! - @brief get a pointer value (explicit) - @copydoc get() - */ - template::value, int>::type = 0> - constexpr const PointerType get() const noexcept - { - // delegate the call to get_ptr - return get_ptr(); - } + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + dump(*i, false, ensure_ascii, indent_step, current_indent); + o->write_character(','); + } - /*! - @brief get a pointer value (implicit) + // last element + assert(not val.m_value.array->empty()); + dump(val.m_value.array->back(), false, ensure_ascii, indent_step, current_indent); - Implicit pointer access to the internally stored JSON value. No copies are - made. + o->write_character(']'); + } - @warning Writing data to the pointee of the result yields an undefined - state. + return; + } - @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref - object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, - @ref number_unsigned_t, or @ref number_float_t. Enforced by a static - assertion. + case value_t::string: + { + o->write_character('\"'); + dump_escaped(*val.m_value.string, ensure_ascii); + o->write_character('\"'); + return; + } - @return pointer to the internally stored JSON value if the requested - pointer type @a PointerType fits to the JSON value; `nullptr` otherwise + case value_t::boolean: + { + if (val.m_value.boolean) + { + o->write_characters("true", 4); + } + else + { + o->write_characters("false", 5); + } + return; + } - @complexity Constant. + case value_t::number_integer: + { + dump_integer(val.m_value.number_integer); + return; + } - @liveexample{The example below shows how pointers to internal values of a - JSON value can be requested. Note that no type conversions are made and a - `nullptr` is returned if the value and the requested pointer type does not - match.,get_ptr} + case value_t::number_unsigned: + { + dump_integer(val.m_value.number_unsigned); + return; + } - @since version 1.0.0 - */ - template::value, int>::type = 0> - PointerType get_ptr() noexcept - { - // get the type of the PointerType (remove pointer and const) - using pointee_t = typename std::remove_const::type>::type>::type; - // make sure the type matches the allowed types - static_assert( - std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - , "incompatible pointer type"); + case value_t::number_float: + { + dump_float(val.m_value.number_float); + return; + } - // delegate the call to get_impl_ptr<>() - return get_impl_ptr(static_cast(nullptr)); + case value_t::discarded: + { + o->write_characters("", 11); + return; + } + + case value_t::null: + { + o->write_characters("null", 4); + return; + } + } } + private: /*! - @brief get a pointer value (implicit) - @copydoc get_ptr() - */ - template::value and - std::is_const::type>::value, int>::type = 0> - constexpr const PointerType get_ptr() const noexcept - { - // get the type of the PointerType (remove pointer and const) - using pointee_t = typename std::remove_const::type>::type>::type; - // make sure the type matches the allowed types - static_assert( - std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - , "incompatible pointer type"); + @brief dump escaped string - // delegate the call to get_impl_ptr<>() const - return get_impl_ptr(static_cast(nullptr)); - } + Escape a string by replacing certain special characters by a sequence of an + escape character (backslash) and another character and other control + characters by a sequence of "\u" followed by a four-digit hex + representation. The escaped string is written to output stream @a o. - /*! - @brief get a reference value (implicit) + @param[in] s the string to escape + @param[in] ensure_ascii whether to escape non-ASCII characters with + \uXXXX sequences - Implicit reference access to the internally stored JSON value. No copies - are made. + @complexity Linear in the length of string @a s. + */ + void dump_escaped(const string_t& s, const bool ensure_ascii) + { + uint32_t codepoint; + uint8_t state = UTF8_ACCEPT; + std::size_t bytes = 0; // number of bytes written to string_buffer - @warning Writing data to the referee of the result yields an undefined - state. + for (std::size_t i = 0; i < s.size(); ++i) + { + const auto byte = static_cast(s[i]); - @tparam ReferenceType reference type; must be a reference to @ref array_t, - @ref object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or - @ref number_float_t. Enforced by static assertion. + switch (decode(state, codepoint, byte)) + { + case UTF8_ACCEPT: // decode found a new code point + { + switch (codepoint) + { + case 0x08: // backspace + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'b'; + break; + } - @return reference to the internally stored JSON value if the requested - reference type @a ReferenceType fits to the JSON value; throws - type_error.303 otherwise + case 0x09: // horizontal tab + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 't'; + break; + } - @throw type_error.303 in case passed type @a ReferenceType is incompatible - with the stored JSON value; see example below + case 0x0A: // newline + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'n'; + break; + } - @complexity Constant. + case 0x0C: // formfeed + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'f'; + break; + } - @liveexample{The example shows several calls to `get_ref()`.,get_ref} + case 0x0D: // carriage return + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'r'; + break; + } - @since version 1.1.0 - */ - template::value, int>::type = 0> - ReferenceType get_ref() - { - // delegate call to get_ref_impl - return get_ref_impl(*this); - } + case 0x22: // quotation mark + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = '\"'; + break; + } - /*! - @brief get a reference value (implicit) - @copydoc get_ref() - */ - template::value and - std::is_const::type>::value, int>::type = 0> - ReferenceType get_ref() const - { - // delegate call to get_ref_impl - return get_ref_impl(*this); - } + case 0x5C: // reverse solidus + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = '\\'; + break; + } - /*! - @brief get a value (implicit) + default: + { + // escape control characters (0x00..0x1F) or, if + // ensure_ascii parameter is used, non-ASCII characters + if ((codepoint <= 0x1F) or (ensure_ascii and (codepoint >= 0x7F))) + { + if (codepoint <= 0xFFFF) + { + std::snprintf(string_buffer.data() + bytes, 7, "\\u%04x", + static_cast(codepoint)); + bytes += 6; + } + else + { + std::snprintf(string_buffer.data() + bytes, 13, "\\u%04x\\u%04x", + static_cast(0xD7C0 + (codepoint >> 10)), + static_cast(0xDC00 + (codepoint & 0x3FF))); + bytes += 12; + } + } + else + { + // copy byte to buffer (all previous bytes + // been copied have in default case above) + string_buffer[bytes++] = s[i]; + } + break; + } + } - Implicit type conversion between the JSON value and a compatible value. - The call is realized by calling @ref get() const. + // write buffer and reset index; there must be 13 bytes + // left, as this is the maximal number of bytes to be + // written ("\uxxxx\uxxxx\0") for one code point + if (string_buffer.size() - bytes < 13) + { + o->write_characters(string_buffer.data(), bytes); + bytes = 0; + } + break; + } - @tparam ValueType non-pointer type compatible to the JSON value, for - instance `int` for JSON integer numbers, `bool` for JSON booleans, or - `std::vector` types for JSON arrays. The character type of @ref string_t - as well as an initializer list of this type is excluded to avoid - ambiguities as these types implicitly convert to `std::string`. + case UTF8_REJECT: // decode found invalid UTF-8 byte + { + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast(byte); + JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + std::to_string(i) + ": 0x" + ss.str())); + } - @return copy of the JSON value, converted to type @a ValueType + default: // decode found yet incomplete multi-byte code point + { + if (not ensure_ascii) + { + // code point will not be escaped - copy byte to buffer + string_buffer[bytes++] = s[i]; + } + break; + } + } + } - @throw type_error.302 in case passed type @a ValueType is incompatible - to the JSON value type (e.g., the JSON value is of type boolean, but a - string is requested); see example below + if (JSON_LIKELY(state == UTF8_ACCEPT)) + { + // write buffer + if (bytes > 0) + { + o->write_characters(string_buffer.data(), bytes); + } + } + else + { + // we finish reading, but do not accept: string was incomplete + std::stringstream ss; + ss << std::setw(2) << std::uppercase << std::setfill('0') << std::hex << static_cast(static_cast(s.back())); + JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + ss.str())); + } + } - @complexity Linear in the size of the JSON value. + /*! + @brief dump an integer - @liveexample{The example below shows several conversions from JSON values - to other types. There a few things to note: (1) Floating-point numbers can - be converted to integers\, (2) A JSON array can be converted to a standard - `std::vector`\, (3) A JSON object can be converted to C++ - associative containers such as `std::unordered_map`.,operator__ValueType} + Dump a given integer to output stream @a o. Works internally with + @a number_buffer. - @since version 1.0.0 + @param[in] x integer number (signed or unsigned) to dump + @tparam NumberType either @a number_integer_t or @a number_unsigned_t */ - template < typename ValueType, typename std::enable_if < - not std::is_pointer::value and - not std::is_same::value -#ifndef _MSC_VER // fix for issue #167 operator<< ambiguity under VS2015 - and not std::is_same>::value -#endif -#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_MSC_VER) && _MSC_VER >1900 && defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464 - and not std::is_same::value -#endif - , int >::type = 0 > - operator ValueType() const + template::value or + std::is_same::value, + int> = 0> + void dump_integer(NumberType x) { - // delegate the call to get<>() const - return get(); - } + // special case for "0" + if (x == 0) + { + o->write_character('0'); + return; + } - /// @} + const bool is_negative = (x <= 0) and (x != 0); // see issue #755 + std::size_t i = 0; + while (x != 0) + { + // spare 1 byte for '\0' + assert(i < number_buffer.size() - 1); - //////////////////// - // element access // - //////////////////// + const auto digit = std::labs(static_cast(x % 10)); + number_buffer[i++] = static_cast('0' + digit); + x /= 10; + } - /// @name element access - /// Access to the JSON value. - /// @{ + if (is_negative) + { + // make sure there is capacity for the '-' + assert(i < number_buffer.size() - 2); + number_buffer[i++] = '-'; + } - /*! - @brief access specified array element with bounds checking + std::reverse(number_buffer.begin(), number_buffer.begin() + i); + o->write_characters(number_buffer.data(), i); + } - Returns a reference to the element at specified location @a idx, with - bounds checking. + /*! + @brief dump a floating-point number - @param[in] idx index of the element to access + Dump a given floating-point number to output stream @a o. Works internally + with @a number_buffer. - @return reference to the element at index @a idx + @param[in] x floating-point number to dump + */ + void dump_float(number_float_t x) + { + // NaN / inf + if (not std::isfinite(x)) + { + o->write_characters("null", 4); + return; + } - @throw type_error.304 if the JSON value is not an array; in this case, - calling `at` with an index makes no sense. See example below. - @throw out_of_range.401 if the index @a idx is out of range of the array; - that is, `idx >= size()`. See example below. + // If number_float_t is an IEEE-754 single or double precision number, + // use the Grisu2 algorithm to produce short numbers which are + // guaranteed to round-trip, using strtof and strtod, resp. + // + // NB: The test below works if == . + static constexpr bool is_ieee_single_or_double + = (std::numeric_limits::is_iec559 and std::numeric_limits::digits == 24 and std::numeric_limits::max_exponent == 128) or + (std::numeric_limits::is_iec559 and std::numeric_limits::digits == 53 and std::numeric_limits::max_exponent == 1024); - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. + dump_float(x, std::integral_constant()); + } - @complexity Constant. + void dump_float(number_float_t x, std::true_type /*is_ieee_single_or_double*/) + { + char* begin = number_buffer.data(); + char* end = ::nlohmann::detail::to_chars(begin, begin + number_buffer.size(), x); - @since version 1.0.0 + o->write_characters(begin, static_cast(end - begin)); + } - @liveexample{The example below shows how array elements can be read and - written using `at()`. It also demonstrates the different exceptions that - can be thrown.,at__size_type} - */ - reference at(size_type idx) + void dump_float(number_float_t x, std::false_type /*is_ieee_single_or_double*/) { - // at only works for arrays - if (is_array()) + // get number of digits for a float -> text -> float round-trip + static constexpr auto d = std::numeric_limits::max_digits10; + + // the actual conversion + std::ptrdiff_t len = snprintf(number_buffer.data(), number_buffer.size(), "%.*g", d, x); + + // negative value indicates an error + assert(len > 0); + // check if buffer was large enough + assert(static_cast(len) < number_buffer.size()); + + // erase thousands separator + if (thousands_sep != '\0') { - JSON_TRY - { - return m_value.array->at(idx); - } - JSON_CATCH (std::out_of_range&) + const auto end = std::remove(number_buffer.begin(), + number_buffer.begin() + len, thousands_sep); + std::fill(end, number_buffer.end(), '\0'); + assert((end - number_buffer.begin()) <= len); + len = (end - number_buffer.begin()); + } + + // convert decimal point to '.' + if (decimal_point != '\0' and decimal_point != '.') + { + const auto dec_pos = std::find(number_buffer.begin(), number_buffer.end(), decimal_point); + if (dec_pos != number_buffer.end()) { - // create better exception explanation - JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + *dec_pos = '.'; } } - else + + o->write_characters(number_buffer.data(), static_cast(len)); + + // determine if need to append ".0" + const bool value_is_int_like = + std::none_of(number_buffer.begin(), number_buffer.begin() + len + 1, + [](char c) + { + return (c == '.' or c == 'e'); + }); + + if (value_is_int_like) { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); + o->write_characters(".0", 2); } } /*! - @brief access specified array element with bounds checking - - Returns a const reference to the element at specified location @a idx, - with bounds checking. - - @param[in] idx index of the element to access - - @return const reference to the element at index @a idx - - @throw type_error.304 if the JSON value is not an array; in this case, - calling `at` with an index makes no sense. See example below. - @throw out_of_range.401 if the index @a idx is out of range of the array; - that is, `idx >= size()`. See example below. + @brief check whether a string is UTF-8 encoded - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. + The function checks each byte of a string whether it is UTF-8 encoded. The + result of the check is stored in the @a state parameter. The function must + be called initially with state 0 (accept). State 1 means the string must + be rejected, because the current byte is not allowed. If the string is + completely processed, but the state is non-zero, the string ended + prematurely; that is, the last byte indicated more bytes should have + followed. - @complexity Constant. + @param[in,out] state the state of the decoding + @param[in,out] codep codepoint (valid only if resulting state is UTF8_ACCEPT) + @param[in] byte next byte to decode + @return new state - @since version 1.0.0 + @note The function has been edited: a std::array is used. - @liveexample{The example below shows how array elements can be read using - `at()`. It also demonstrates the different exceptions that can be thrown., - at__size_type_const} + @copyright Copyright (c) 2008-2009 Bjoern Hoehrmann + @sa http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ */ - const_reference at(size_type idx) const + static uint8_t decode(uint8_t& state, uint32_t& codep, const uint8_t byte) noexcept { - // at only works for arrays - if (is_array()) + static const std::array utf8d = { - JSON_TRY - { - return m_value.array->at(idx); - } - JSON_CATCH (std::out_of_range&) { - // create better exception explanation - JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 00..1F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 20..3F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 40..5F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 60..7F + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, // 80..9F + 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // A0..BF + 8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, // C0..DF + 0xA, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x4, 0x3, 0x3, // E0..EF + 0xB, 0x6, 0x6, 0x6, 0x5, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, // F0..FF + 0x0, 0x1, 0x2, 0x3, 0x5, 0x8, 0x7, 0x1, 0x1, 0x1, 0x4, 0x6, 0x1, 0x1, 0x1, 0x1, // s0..s0 + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, // s1..s2 + 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, // s3..s4 + 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, // s5..s6 + 1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 // s7..s8 } - } - else - { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); - } + }; + + const uint8_t type = utf8d[byte]; + + codep = (state != UTF8_ACCEPT) + ? (byte & 0x3fu) | (codep << 6) + : static_cast(0xff >> type) & (byte); + + state = utf8d[256u + state * 16u + type]; + return state; } - /*! - @brief access specified object element with bounds checking + private: + /// the output of the serializer + output_adapter_t o = nullptr; + + /// a (hopefully) large enough character buffer + std::array number_buffer{{}}; + + /// the locale + const std::lconv* loc = nullptr; + /// the locale's thousand separator character + const char thousands_sep = '\0'; + /// the locale's decimal point character + const char decimal_point = '\0'; + + /// string buffer + std::array string_buffer{{}}; + + /// the indentation character + const char indent_char; + /// the indentation string + string_t indent_string; +}; +} +} - Returns a reference to the element at with specified key @a key, with - bounds checking. +// #include - @param[in] key key of the element to access - @return reference to the element at key @a key +#include +#include - @throw type_error.304 if the JSON value is not an object; in this case, - calling `at` with a key makes no sense. See example below. - @throw out_of_range.403 if the key @a key is is not stored in the object; - that is, `find(key) == end()`. See example below. +namespace nlohmann +{ +namespace detail +{ +template +class json_ref +{ + public: + using value_type = BasicJsonType; - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. + json_ref(value_type&& value) + : owned_value(std::move(value)), value_ref(&owned_value), is_rvalue(true) + {} - @complexity Logarithmic in the size of the container. + json_ref(const value_type& value) + : value_ref(const_cast(&value)), is_rvalue(false) + {} - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @sa @ref value() for access by value with a default value + json_ref(std::initializer_list init) + : owned_value(init), value_ref(&owned_value), is_rvalue(true) + {} - @since version 1.0.0 + template + json_ref(Args&& ... args) + : owned_value(std::forward(args)...), value_ref(&owned_value), is_rvalue(true) + {} - @liveexample{The example below shows how object elements can be read and - written using `at()`. It also demonstrates the different exceptions that - can be thrown.,at__object_t_key_type} - */ - reference at(const typename object_t::key_type& key) + // class should be movable only + json_ref(json_ref&&) = default; + json_ref(const json_ref&) = delete; + json_ref& operator=(const json_ref&) = delete; + + value_type moved_or_copied() const { - // at only works for objects - if (is_object()) - { - JSON_TRY - { - return m_value.object->at(key); - } - JSON_CATCH (std::out_of_range&) - { - // create better exception explanation - JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); - } - } - else + if (is_rvalue) { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); + return std::move(*value_ref); } + return *value_ref; } - /*! - @brief access specified object element with bounds checking + value_type const& operator*() const + { + return *static_cast(value_ref); + } - Returns a const reference to the element at with specified key @a key, - with bounds checking. + value_type const* operator->() const + { + return static_cast(value_ref); + } - @param[in] key key of the element to access + private: + mutable value_type owned_value = nullptr; + value_type* value_ref = nullptr; + const bool is_rvalue; +}; +} +} - @return const reference to the element at key @a key +// #include - @throw type_error.304 if the JSON value is not an object; in this case, - calling `at` with a key makes no sense. See example below. - @throw out_of_range.403 if the key @a key is is not stored in the object; - that is, `find(key) == end()`. See example below. - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. +#include // assert +#include // accumulate +#include // string +#include // vector - @complexity Logarithmic in the size of the container. +// #include - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @sa @ref value() for access by value with a default value +// #include - @since version 1.0.0 +// #include - @liveexample{The example below shows how object elements can be read using - `at()`. It also demonstrates the different exceptions that can be thrown., - at__object_t_key_type_const} - */ - const_reference at(const typename object_t::key_type& key) const - { - // at only works for objects - if (is_object()) - { - JSON_TRY - { - return m_value.object->at(key); - } - JSON_CATCH (std::out_of_range&) - { - // create better exception explanation - JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); - } - } - else - { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); - } - } +namespace nlohmann +{ +template +class json_pointer +{ + // allow basic_json to access private members + NLOHMANN_BASIC_JSON_TPL_DECLARATION + friend class basic_json; + + public: /*! - @brief access specified array element + @brief create JSON pointer - Returns a reference to the element at specified location @a idx. + Create a JSON pointer according to the syntax described in + [Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3). - @note If @a idx is beyond the range of the array (i.e., `idx >= size()`), - then the array is silently filled up with `null` values to make `idx` a - valid reference to the last stored element. + @param[in] s string representing the JSON pointer; if omitted, the empty + string is assumed which references the whole JSON value - @param[in] idx index of the element to access + @throw parse_error.107 if the given JSON pointer @a s is nonempty and does + not begin with a slash (`/`); see example below - @return reference to the element at index @a idx + @throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s is + not followed by `0` (representing `~`) or `1` (representing `/`); see + example below - @throw type_error.305 if the JSON value is not an array or null; in that - cases, using the [] operator with an index makes no sense. + @liveexample{The example shows the construction several valid JSON pointers + as well as the exceptional behavior.,json_pointer} - @complexity Constant if @a idx is in the range of the array. Otherwise - linear in `idx - size()`. + @since version 2.0.0 + */ + explicit json_pointer(const std::string& s = "") + : reference_tokens(split(s)) + {} - @liveexample{The example below shows how array elements can be read and - written using `[]` operator. Note the addition of `null` - values.,operatorarray__size_type} + /*! + @brief return a string representation of the JSON pointer - @since version 1.0.0 + @invariant For each JSON pointer `ptr`, it holds: + @code {.cpp} + ptr == json_pointer(ptr.to_string()); + @endcode + + @return a string representation of the JSON pointer + + @liveexample{The example shows the result of `to_string`., + json_pointer__to_string} + + @since version 2.0.0 */ - reference operator[](size_type idx) + std::string to_string() const noexcept { - // implicitly convert null value to an empty array - if (is_null()) + return std::accumulate(reference_tokens.begin(), reference_tokens.end(), + std::string{}, + [](const std::string & a, const std::string & b) { - m_type = value_t::array; - m_value.array = create(); - assert_invariant(); - } + return a + "/" + escape(b); + }); + } - // operator[] only works for arrays - if (is_array()) - { - // fill up array with null values if given idx is outside range - if (idx >= m_value.array->size()) - { - m_value.array->insert(m_value.array->end(), - idx - m_value.array->size() + 1, - basic_json()); - } + /// @copydoc to_string() + operator std::string() const + { + return to_string(); + } + + /*! + @param[in] s reference token to be converted into an array index - return m_value.array->operator[](idx); + @return integer representation of @a s + + @throw out_of_range.404 if string @a s could not be converted to an integer + */ + static int array_index(const std::string& s) + { + std::size_t processed_chars = 0; + const int res = std::stoi(s, &processed_chars); + + // check if the string was completely read + if (JSON_UNLIKELY(processed_chars != s.size())) + { + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + s + "'")); } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + return res; } + private: /*! - @brief access specified array element + @brief remove and return last reference pointer + @throw out_of_range.405 if JSON pointer has no parent + */ + std::string pop_back() + { + if (JSON_UNLIKELY(is_root())) + { + JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent")); + } - Returns a const reference to the element at specified location @a idx. + auto last = reference_tokens.back(); + reference_tokens.pop_back(); + return last; + } - @param[in] idx index of the element to access + /// return whether pointer points to the root document + bool is_root() const + { + return reference_tokens.empty(); + } - @return const reference to the element at index @a idx + json_pointer top() const + { + if (JSON_UNLIKELY(is_root())) + { + JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent")); + } - @throw type_error.305 if the JSON value is not an array; in that cases, - using the [] operator with an index makes no sense. + json_pointer result = *this; + result.reference_tokens = {reference_tokens[0]}; + return result; + } - @complexity Constant. + /*! + @brief create and return a reference to the pointed to value - @liveexample{The example below shows how array elements can be read using - the `[]` operator.,operatorarray__size_type_const} + @complexity Linear in the number of reference tokens. - @since version 1.0.0 + @throw parse_error.109 if array index is not a number + @throw type_error.313 if value cannot be unflattened */ - const_reference operator[](size_type idx) const + BasicJsonType& get_and_create(BasicJsonType& j) const { - // const operator[] only works for arrays - if (is_array()) + using size_type = typename BasicJsonType::size_type; + auto result = &j; + + // in case no reference tokens exist, return a reference to the JSON value + // j which will be overwritten by a primitive value + for (const auto& reference_token : reference_tokens) { - return m_value.array->operator[](idx); + switch (result->m_type) + { + case detail::value_t::null: + { + if (reference_token == "0") + { + // start a new array if reference token is 0 + result = &result->operator[](0); + } + else + { + // start a new object otherwise + result = &result->operator[](reference_token); + } + break; + } + + case detail::value_t::object: + { + // create an entry in the object + result = &result->operator[](reference_token); + break; + } + + case detail::value_t::array: + { + // create an entry in the array + JSON_TRY + { + result = &result->operator[](static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } + + /* + The following code is only reached if there exists a reference + token _and_ the current value is primitive. In this case, we have + an error situation, because primitive values may only occur as + single value; that is, with an empty list of reference tokens. + */ + default: + JSON_THROW(detail::type_error::create(313, "invalid value to unflatten")); + } } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + return *result; } /*! - @brief access specified object element + @brief return a reference to the pointed to value - Returns a reference to the element at with specified key @a key. + @note This version does not throw if a value is not present, but tries to + create nested values instead. For instance, calling this function + with pointer `"/this/that"` on a null value is equivalent to calling + `operator[]("this").operator[]("that")` on that value, effectively + changing the null value to an object. - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. + @param[in] ptr a JSON value - @param[in] key key of the element to access + @return reference to the JSON value pointed to by the JSON pointer - @return reference to the element at key @a key + @complexity Linear in the length of the JSON pointer. - @throw type_error.305 if the JSON value is not an object or null; in that - cases, using the [] operator with a key makes no sense. + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.404 if the JSON pointer can not be resolved + */ + BasicJsonType& get_unchecked(BasicJsonType* ptr) const + { + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) + { + // convert null values to arrays or objects before continuing + if (ptr->m_type == detail::value_t::null) + { + // check if reference token is a number + const bool nums = + std::all_of(reference_token.begin(), reference_token.end(), + [](const char x) + { + return (x >= '0' and x <= '9'); + }); - @complexity Logarithmic in the size of the container. + // change value to array for numbers or "-" or to object otherwise + *ptr = (nums or reference_token == "-") + ? detail::value_t::array + : detail::value_t::object; + } - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} + switch (ptr->m_type) + { + case detail::value_t::object: + { + // use unchecked object access + ptr = &ptr->operator[](reference_token); + break; + } - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + case detail::value_t::array: + { + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } - @since version 1.0.0 - */ - reference operator[](const typename object_t::key_type& key) - { - // implicitly convert null value to an empty object - if (is_null()) - { - m_type = value_t::object; - m_value.object = create(); - assert_invariant(); - } + if (reference_token == "-") + { + // explicitly treat "-" as index beyond the end + ptr = &ptr->operator[](ptr->m_value.array->size()); + } + else + { + // convert array index to number; unchecked access + JSON_TRY + { + ptr = &ptr->operator[]( + static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + } + break; + } - // operator[] only works for objects - if (is_object()) - { - return m_value.object->operator[](key); + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + return *ptr; } /*! - @brief read-only access specified object element - - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.402 if the array index '-' is used + @throw out_of_range.404 if the JSON pointer can not be resolved + */ + BasicJsonType& get_checked(BasicJsonType* ptr) const + { + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) + { + switch (ptr->m_type) + { + case detail::value_t::object: + { + // note: at performs range check + ptr = &ptr->at(reference_token); + break; + } - @warning If the element with key @a key does not exist, the behavior is - undefined. + case detail::value_t::array: + { + if (JSON_UNLIKELY(reference_token == "-")) + { + // "-" always fails the range check + JSON_THROW(detail::out_of_range::create(402, + "array index '-' (" + std::to_string(ptr->m_value.array->size()) + + ") is out of range")); + } - @param[in] key key of the element to access + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } - @return const reference to the element at key @a key + // note: at performs range check + JSON_TRY + { + ptr = &ptr->at(static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } - @pre The element with key @a key must exist. **This precondition is - enforced with an assertion.** + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } + } - @throw type_error.305 if the JSON value is not an object; in that cases, - using the [] operator with a key makes no sense. + return *ptr; + } - @complexity Logarithmic in the size of the container. + /*! + @brief return a const reference to the pointed to value - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} + @param[in] ptr a JSON value - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + @return const reference to the JSON value pointed to by the JSON + pointer - @since version 1.0.0 + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.402 if the array index '-' is used + @throw out_of_range.404 if the JSON pointer can not be resolved */ - const_reference operator[](const typename object_t::key_type& key) const + const BasicJsonType& get_unchecked(const BasicJsonType* ptr) const { - // const operator[] only works for objects - if (is_object()) + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) { - assert(m_value.object->find(key) != m_value.object->end()); - return m_value.object->find(key)->second; - } + switch (ptr->m_type) + { + case detail::value_t::object: + { + // use unchecked object access + ptr = &ptr->operator[](reference_token); + break; + } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); - } + case detail::value_t::array: + { + if (JSON_UNLIKELY(reference_token == "-")) + { + // "-" cannot be used for const access + JSON_THROW(detail::out_of_range::create(402, + "array index '-' (" + std::to_string(ptr->m_value.array->size()) + + ") is out of range")); + } - /*! - @brief access specified object element + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } - Returns a reference to the element at with specified key @a key. + // use unchecked array access + JSON_TRY + { + ptr = &ptr->operator[]( + static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } + } - @param[in] key key of the element to access + return *ptr; + } - @return reference to the element at key @a key + /*! + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.402 if the array index '-' is used + @throw out_of_range.404 if the JSON pointer can not be resolved + */ + const BasicJsonType& get_checked(const BasicJsonType* ptr) const + { + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) + { + switch (ptr->m_type) + { + case detail::value_t::object: + { + // note: at performs range check + ptr = &ptr->at(reference_token); + break; + } - @throw type_error.305 if the JSON value is not an object or null; in that - cases, using the [] operator with a key makes no sense. + case detail::value_t::array: + { + if (JSON_UNLIKELY(reference_token == "-")) + { + // "-" always fails the range check + JSON_THROW(detail::out_of_range::create(402, + "array index '-' (" + std::to_string(ptr->m_value.array->size()) + + ") is out of range")); + } - @complexity Logarithmic in the size of the container. + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} + // note: at performs range check + JSON_TRY + { + ptr = &ptr->at(static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } + } - @since version 1.0.0 - */ - template - reference operator[](T * (&key)[n]) - { - return operator[](static_cast(key)); + return *ptr; } /*! - @brief read-only access specified object element + @brief split the string input to reference tokens - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. + @note This function is only called by the json_pointer constructor. + All exceptions below are documented there. - @warning If the element with key @a key does not exist, the behavior is - undefined. + @throw parse_error.107 if the pointer is not empty or begins with '/' + @throw parse_error.108 if character '~' is not followed by '0' or '1' + */ + static std::vector split(const std::string& reference_string) + { + std::vector result; + + // special case: empty reference string -> no reference tokens + if (reference_string.empty()) + { + return result; + } - @note This function is required for compatibility reasons with Clang. + // check if nonempty reference string begins with slash + if (JSON_UNLIKELY(reference_string[0] != '/')) + { + JSON_THROW(detail::parse_error::create(107, 1, + "JSON pointer must be empty or begin with '/' - was: '" + + reference_string + "'")); + } + + // extract the reference tokens: + // - slash: position of the last read slash (or end of string) + // - start: position after the previous slash + for ( + // search for the first slash after the first character + std::size_t slash = reference_string.find_first_of('/', 1), + // set the beginning of the first reference token + start = 1; + // we can stop if start == string::npos+1 = 0 + start != 0; + // set the beginning of the next reference token + // (will eventually be 0 if slash == std::string::npos) + start = slash + 1, + // find next slash + slash = reference_string.find_first_of('/', start)) + { + // use the text between the beginning of the reference token + // (start) and the last slash (slash). + auto reference_token = reference_string.substr(start, slash - start); + + // check reference tokens are properly escaped + for (std::size_t pos = reference_token.find_first_of('~'); + pos != std::string::npos; + pos = reference_token.find_first_of('~', pos + 1)) + { + assert(reference_token[pos] == '~'); - @param[in] key key of the element to access + // ~ must be followed by 0 or 1 + if (JSON_UNLIKELY(pos == reference_token.size() - 1 or + (reference_token[pos + 1] != '0' and + reference_token[pos + 1] != '1'))) + { + JSON_THROW(detail::parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'")); + } + } - @return const reference to the element at key @a key + // finally, store the reference token + unescape(reference_token); + result.push_back(reference_token); + } - @throw type_error.305 if the JSON value is not an object; in that cases, - using the [] operator with a key makes no sense. + return result; + } - @complexity Logarithmic in the size of the container. + /*! + @brief replace all occurrences of a substring by another string - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} + @param[in,out] s the string to manipulate; changed so that all + occurrences of @a f are replaced with @a t + @param[in] f the substring to replace with @a t + @param[in] t the string to replace @a f - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + @pre The search string @a f must not be empty. **This precondition is + enforced with an assertion.** - @since version 1.0.0 + @since version 2.0.0 */ - template - const_reference operator[](T * (&key)[n]) const + static void replace_substring(std::string& s, const std::string& f, + const std::string& t) { - return operator[](static_cast(key)); + assert(not f.empty()); + for (auto pos = s.find(f); // find first occurrence of f + pos != std::string::npos; // make sure f was found + s.replace(pos, f.size(), t), // replace with t, and + pos = s.find(f, pos + t.size())) // find next occurrence of f + {} } - /*! - @brief access specified object element - - Returns a reference to the element at with specified key @a key. + /// escape "~"" to "~0" and "/" to "~1" + static std::string escape(std::string s) + { + replace_substring(s, "~", "~0"); + replace_substring(s, "/", "~1"); + return s; + } - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. + /// unescape "~1" to tilde and "~0" to slash (order is important!) + static void unescape(std::string& s) + { + replace_substring(s, "~1", "/"); + replace_substring(s, "~0", "~"); + } - @param[in] key key of the element to access + /*! + @param[in] reference_string the reference string to the current value + @param[in] value the value to consider + @param[in,out] result the result object to insert values to - @return reference to the element at key @a key + @note Empty objects or arrays are flattened to `null`. + */ + static void flatten(const std::string& reference_string, + const BasicJsonType& value, + BasicJsonType& result) + { + switch (value.m_type) + { + case detail::value_t::array: + { + if (value.m_value.array->empty()) + { + // flatten empty array as null + result[reference_string] = nullptr; + } + else + { + // iterate array and use index as reference string + for (std::size_t i = 0; i < value.m_value.array->size(); ++i) + { + flatten(reference_string + "/" + std::to_string(i), + value.m_value.array->operator[](i), result); + } + } + break; + } - @throw type_error.305 if the JSON value is not an object or null; in that - cases, using the [] operator with a key makes no sense. + case detail::value_t::object: + { + if (value.m_value.object->empty()) + { + // flatten empty object as null + result[reference_string] = nullptr; + } + else + { + // iterate object and use keys as reference string + for (const auto& element : *value.m_value.object) + { + flatten(reference_string + "/" + escape(element.first), element.second, result); + } + } + break; + } - @complexity Logarithmic in the size of the container. + default: + { + // add primitive value with its reference string + result[reference_string] = value; + break; + } + } + } - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} + /*! + @param[in] value flattened JSON - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + @return unflattened JSON - @since version 1.1.0 + @throw parse_error.109 if array index is not a number + @throw type_error.314 if value is not an object + @throw type_error.315 if object values are not primitive + @throw type_error.313 if value cannot be unflattened */ - template - reference operator[](T* key) + static BasicJsonType + unflatten(const BasicJsonType& value) { - // implicitly convert null to object - if (is_null()) + if (JSON_UNLIKELY(not value.is_object())) { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); + JSON_THROW(detail::type_error::create(314, "only objects can be unflattened")); } - // at only works for objects - if (is_object()) + BasicJsonType result; + + // iterate the JSON object values + for (const auto& element : *value.m_value.object) { - return m_value.object->operator[](key); + if (JSON_UNLIKELY(not element.second.is_primitive())) + { + JSON_THROW(detail::type_error::create(315, "values in object must be primitive")); + } + + // assign value to reference pointed to by JSON pointer; Note that if + // the JSON pointer is "" (i.e., points to the whole value), function + // get_and_create returns a reference to result itself. An assignment + // will then create a primitive value. + json_pointer(element.first).get_and_create(result) = element.second; } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + return result; } - /*! - @brief read-only access specified object element + friend bool operator==(json_pointer const& lhs, + json_pointer const& rhs) noexcept + { + return (lhs.reference_tokens == rhs.reference_tokens); + } - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. + friend bool operator!=(json_pointer const& lhs, + json_pointer const& rhs) noexcept + { + return not (lhs == rhs); + } - @warning If the element with key @a key does not exist, the behavior is - undefined. + /// the reference tokens + std::vector reference_tokens; +}; +} - @param[in] key key of the element to access +// #include - @return const reference to the element at key @a key - @pre The element with key @a key must exist. **This precondition is - enforced with an assertion.** +#include - @throw type_error.305 if the JSON value is not an object; in that cases, - using the [] operator with a key makes no sense. +// #include - @complexity Logarithmic in the size of the container. +// #include - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value +namespace nlohmann +{ +template +struct adl_serializer +{ + /*! + @brief convert a JSON value to any value type - @since version 1.1.0 + This function is usually called by the `get()` function of the + @ref basic_json class (either explicit or via conversion operators). + + @param[in] j JSON value to read from + @param[in,out] val value to write to */ - template - const_reference operator[](T* key) const + template + static void from_json(BasicJsonType&& j, ValueType& val) noexcept( + noexcept(::nlohmann::from_json(std::forward(j), val))) { - // at only works for objects - if (is_object()) - { - assert(m_value.object->find(key) != m_value.object->end()); - return m_value.object->find(key)->second; - } - - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + ::nlohmann::from_json(std::forward(j), val); } /*! - @brief access specified object element with default value + @brief convert any value type to a JSON value - Returns either a copy of an object's element at the specified key @a key - or a given default value if no element with key @a key exists. + This function is usually called by the constructors of the @ref basic_json + class. - The function is basically equivalent to executing - @code {.cpp} - try { - return at(key); - } catch(out_of_range) { - return default_value; + @param[in,out] j JSON value to write to + @param[in] val value to read from + */ + template + static void to_json(BasicJsonType& j, ValueType&& val) noexcept( + noexcept(::nlohmann::to_json(j, std::forward(val)))) + { + ::nlohmann::to_json(j, std::forward(val)); } - @endcode - - @note Unlike @ref at(const typename object_t::key_type&), this function - does not throw if the given key @a key was not found. - - @note Unlike @ref operator[](const typename object_t::key_type& key), this - function does not implicitly add an element to the position defined by @a - key. This function is furthermore also applicable to const objects. +}; +} - @param[in] key key of the element to access - @param[in] default_value the value to return if @a key is not found - @tparam ValueType type compatible to JSON values, for instance `int` for - JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for - JSON arrays. Note the type of the expected value at @a key and the default - value @a default_value must be compatible. +/*! +@brief namespace for Niels Lohmann +@see https://github.com/nlohmann +@since version 1.0.0 +*/ +namespace nlohmann +{ - @return copy of the element at key @a key or @a default_value if @a key - is not found +/*! +@brief a class to store JSON values - @throw type_error.306 if the JSON value is not an objec; in that cases, - using `value()` with a key makes no sense. +@tparam ObjectType type for JSON objects (`std::map` by default; will be used +in @ref object_t) +@tparam ArrayType type for JSON arrays (`std::vector` by default; will be used +in @ref array_t) +@tparam StringType type for JSON strings and object keys (`std::string` by +default; will be used in @ref string_t) +@tparam BooleanType type for JSON booleans (`bool` by default; will be used +in @ref boolean_t) +@tparam NumberIntegerType type for JSON integer numbers (`int64_t` by +default; will be used in @ref number_integer_t) +@tparam NumberUnsignedType type for JSON unsigned integer numbers (@c +`uint64_t` by default; will be used in @ref number_unsigned_t) +@tparam NumberFloatType type for JSON floating-point numbers (`double` by +default; will be used in @ref number_float_t) +@tparam AllocatorType type of the allocator to use (`std::allocator` by +default) +@tparam JSONSerializer the serializer to resolve internal calls to `to_json()` +and `from_json()` (@ref adl_serializer by default) - @complexity Logarithmic in the size of the container. +@requirement The class satisfies the following concept requirements: +- Basic + - [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible): + JSON values can be default constructed. The result will be a JSON null + value. + - [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible): + A JSON value can be constructed from an rvalue argument. + - [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible): + A JSON value can be copy-constructed from an lvalue expression. + - [MoveAssignable](http://en.cppreference.com/w/cpp/concept/MoveAssignable): + A JSON value van be assigned from an rvalue argument. + - [CopyAssignable](http://en.cppreference.com/w/cpp/concept/CopyAssignable): + A JSON value can be copy-assigned from an lvalue expression. + - [Destructible](http://en.cppreference.com/w/cpp/concept/Destructible): + JSON values can be destructed. +- Layout + - [StandardLayoutType](http://en.cppreference.com/w/cpp/concept/StandardLayoutType): + JSON values have + [standard layout](http://en.cppreference.com/w/cpp/language/data_members#Standard_layout): + All non-static data members are private and standard layout types, the + class has no virtual functions or (virtual) base classes. +- Library-wide + - [EqualityComparable](http://en.cppreference.com/w/cpp/concept/EqualityComparable): + JSON values can be compared with `==`, see @ref + operator==(const_reference,const_reference). + - [LessThanComparable](http://en.cppreference.com/w/cpp/concept/LessThanComparable): + JSON values can be compared with `<`, see @ref + operator<(const_reference,const_reference). + - [Swappable](http://en.cppreference.com/w/cpp/concept/Swappable): + Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of + other compatible types, using unqualified function call @ref swap(). + - [NullablePointer](http://en.cppreference.com/w/cpp/concept/NullablePointer): + JSON values can be compared against `std::nullptr_t` objects which are used + to model the `null` value. +- Container + - [Container](http://en.cppreference.com/w/cpp/concept/Container): + JSON values can be used like STL containers and provide iterator access. + - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer); + JSON values can be used like STL containers and provide reverse iterator + access. - @liveexample{The example below shows how object elements can be queried - with a default value.,basic_json__value} +@invariant The member variables @a m_value and @a m_type have the following +relationship: +- If `m_type == value_t::object`, then `m_value.object != nullptr`. +- If `m_type == value_t::array`, then `m_value.array != nullptr`. +- If `m_type == value_t::string`, then `m_value.string != nullptr`. +The invariants are checked by member function assert_invariant(). - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference +@internal +@note ObjectType trick from http://stackoverflow.com/a/9860911 +@endinternal - @since version 1.0.0 - */ - template::value, int>::type = 0> - ValueType value(const typename object_t::key_type& key, ValueType default_value) const - { - // at only works for objects - if (is_object()) - { - // if key is found, return value and given default value otherwise - const auto it = find(key); - if (it != end()) - { - return *it; - } +@see [RFC 7159: The JavaScript Object Notation (JSON) Data Interchange +Format](http://rfc7159.net/rfc7159) - return default_value; - } - else - { - JSON_THROW(type_error::create(306, "cannot use value() with " + type_name())); - } - } +@since version 1.0.0 - /*! - @brief overload for a default value of type const char* - @copydoc basic_json::value(const typename object_t::key_type&, ValueType) const - */ - string_t value(const typename object_t::key_type& key, const char* default_value) const - { - return value(key, string_t(default_value)); - } +@nosubgrouping +*/ +NLOHMANN_BASIC_JSON_TPL_DECLARATION +class basic_json +{ + private: + template friend struct detail::external_constructor; + friend ::nlohmann::json_pointer; + friend ::nlohmann::detail::parser; + friend ::nlohmann::detail::serializer; + template + friend class ::nlohmann::detail::iter_impl; + template + friend class ::nlohmann::detail::binary_writer; + template + friend class ::nlohmann::detail::binary_reader; + template + friend class ::nlohmann::detail::json_sax_dom_parser; + template + friend class ::nlohmann::detail::json_sax_dom_callback_parser; - /*! - @brief access specified object element via JSON Pointer with default value + /// workaround type for MSVC + using basic_json_t = NLOHMANN_BASIC_JSON_TPL; - Returns either a copy of an object's element at the specified key @a key - or a given default value if no element with key @a key exists. + // convenience aliases for types residing in namespace detail; + using lexer = ::nlohmann::detail::lexer; + using parser = ::nlohmann::detail::parser; - The function is basically equivalent to executing - @code {.cpp} - try { - return at(ptr); - } catch(out_of_range) { - return default_value; - } - @endcode + using primitive_iterator_t = ::nlohmann::detail::primitive_iterator_t; + template + using internal_iterator = ::nlohmann::detail::internal_iterator; + template + using iter_impl = ::nlohmann::detail::iter_impl; + template + using iteration_proxy = ::nlohmann::detail::iteration_proxy; + template using json_reverse_iterator = ::nlohmann::detail::json_reverse_iterator; - @note Unlike @ref at(const json_pointer&), this function does not throw - if the given key @a key was not found. + template + using output_adapter_t = ::nlohmann::detail::output_adapter_t; - @param[in] ptr a JSON pointer to the element to access - @param[in] default_value the value to return if @a ptr found no value + using binary_reader = ::nlohmann::detail::binary_reader; + template using binary_writer = ::nlohmann::detail::binary_writer; - @tparam ValueType type compatible to JSON values, for instance `int` for - JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for - JSON arrays. Note the type of the expected value at @a key and the default - value @a default_value must be compatible. + using serializer = ::nlohmann::detail::serializer; - @return copy of the element at key @a key or @a default_value if @a key - is not found + public: + using value_t = detail::value_t; + /// @copydoc nlohmann::json_pointer + using json_pointer = ::nlohmann::json_pointer; + template + using json_serializer = JSONSerializer; + /// helper type for initializer lists of basic_json values + using initializer_list_t = std::initializer_list>; - @throw type_error.306 if the JSON value is not an objec; in that cases, - using `value()` with a key makes no sense. + using input_format_t = detail::input_format_t; - @complexity Logarithmic in the size of the container. + //////////////// + // exceptions // + //////////////// - @liveexample{The example below shows how object elements can be queried - with a default value.,basic_json__value_ptr} + /// @name exceptions + /// Classes to implement user-defined exceptions. + /// @{ - @sa @ref operator[](const json_pointer&) for unchecked access by reference + /// @copydoc detail::exception + using exception = detail::exception; + /// @copydoc detail::parse_error + using parse_error = detail::parse_error; + /// @copydoc detail::invalid_iterator + using invalid_iterator = detail::invalid_iterator; + /// @copydoc detail::type_error + using type_error = detail::type_error; + /// @copydoc detail::out_of_range + using out_of_range = detail::out_of_range; + /// @copydoc detail::other_error + using other_error = detail::other_error; - @since version 2.0.2 - */ - template::value, int>::type = 0> - ValueType value(const json_pointer& ptr, ValueType default_value) const - { - // at only works for objects - if (is_object()) - { - // if pointer resolves a value, return it or use default value - JSON_TRY - { - return ptr.get_checked(this); - } - JSON_CATCH (out_of_range&) - { - return default_value; - } - } + /// @} - JSON_THROW(type_error::create(306, "cannot use value() with " + type_name())); - } - /*! - @brief overload for a default value of type const char* - @copydoc basic_json::value(const json_pointer&, ValueType) const - */ - string_t value(const json_pointer& ptr, const char* default_value) const - { - return value(ptr, string_t(default_value)); - } + ///////////////////// + // container types // + ///////////////////// - /*! - @brief access the first element + /// @name container types + /// The canonic container types to use @ref basic_json like any other STL + /// container. + /// @{ - Returns a reference to the first element in the container. For a JSON - container `c`, the expression `c.front()` is equivalent to `*c.begin()`. + /// the type of elements in a basic_json container + using value_type = basic_json; - @return In case of a structured type (array or object), a reference to the - first element is returned. In case of number, string, or boolean values, a - reference to the value is returned. + /// the type of an element reference + using reference = value_type&; + /// the type of an element const reference + using const_reference = const value_type&; - @complexity Constant. + /// a type to represent differences between iterators + using difference_type = std::ptrdiff_t; + /// a type to represent container sizes + using size_type = std::size_t; - @pre The JSON value must not be `null` (would throw `std::out_of_range`) - or an empty array or object (undefined behavior, **guarded by - assertions**). - @post The JSON value remains unchanged. + /// the allocator type + using allocator_type = AllocatorType; - @throw invalid_iterator.214 when called on `null` value + /// the type of an element pointer + using pointer = typename std::allocator_traits::pointer; + /// the type of an element const pointer + using const_pointer = typename std::allocator_traits::const_pointer; - @liveexample{The following code shows an example for `front()`.,front} + /// an iterator for a basic_json container + using iterator = iter_impl; + /// a const iterator for a basic_json container + using const_iterator = iter_impl; + /// a reverse iterator for a basic_json container + using reverse_iterator = json_reverse_iterator; + /// a const reverse iterator for a basic_json container + using const_reverse_iterator = json_reverse_iterator; - @sa @ref back() -- access the last element + /// @} - @since version 1.0.0 - */ - reference front() - { - return *begin(); - } /*! - @copydoc basic_json::front() + @brief returns the allocator associated with the container */ - const_reference front() const + static allocator_type get_allocator() { - return *cbegin(); + return allocator_type(); } /*! - @brief access the last element - - Returns a reference to the last element in the container. For a JSON - container `c`, the expression `c.back()` is equivalent to - @code {.cpp} - auto tmp = c.end(); - --tmp; - return *tmp; - @endcode - - @return In case of a structured type (array or object), a reference to the - last element is returned. In case of number, string, or boolean values, a - reference to the value is returned. + @brief returns version information on the library - @complexity Constant. + This function returns a JSON object with information about the library, + including the version number and information on the platform and compiler. - @pre The JSON value must not be `null` (would throw `std::out_of_range`) - or an empty array or object (undefined behavior, **guarded by - assertions**). - @post The JSON value remains unchanged. + @return JSON object holding version information + key | description + ----------- | --------------- + `compiler` | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version). + `copyright` | The copyright line for the library as string. + `name` | The name of the library as string. + `platform` | The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`. + `url` | The URL of the project as string. + `version` | The version of the library. It is an object with the following keys: `major`, `minor`, and `patch` as defined by [Semantic Versioning](http://semver.org), and `string` (the version string). - @throw invalid_iterator.214 when called on a `null` value. See example - below. + @liveexample{The following code shows an example output of the `meta()` + function.,meta} - @liveexample{The following code shows an example for `back()`.,back} + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @sa @ref front() -- access the first element + @complexity Constant. - @since version 1.0.0 + @since 2.1.0 */ - reference back() + static basic_json meta() { - auto tmp = end(); - --tmp; - return *tmp; - } + basic_json result; + + result["copyright"] = "(C) 2013-2017 Niels Lohmann"; + result["name"] = "JSON for Modern C++"; + result["url"] = "https://github.com/nlohmann/json"; + result["version"]["string"] = + std::to_string(NLOHMANN_JSON_VERSION_MAJOR) + "." + + std::to_string(NLOHMANN_JSON_VERSION_MINOR) + "." + + std::to_string(NLOHMANN_JSON_VERSION_PATCH); + result["version"]["major"] = NLOHMANN_JSON_VERSION_MAJOR; + result["version"]["minor"] = NLOHMANN_JSON_VERSION_MINOR; + result["version"]["patch"] = NLOHMANN_JSON_VERSION_PATCH; + +#ifdef _WIN32 + result["platform"] = "win32"; +#elif defined __linux__ + result["platform"] = "linux"; +#elif defined __APPLE__ + result["platform"] = "apple"; +#elif defined __unix__ + result["platform"] = "unix"; +#else + result["platform"] = "unknown"; +#endif + +#if defined(__ICC) || defined(__INTEL_COMPILER) + result["compiler"] = {{"family", "icc"}, {"version", __INTEL_COMPILER}}; +#elif defined(__clang__) + result["compiler"] = {{"family", "clang"}, {"version", __clang_version__}}; +#elif defined(__GNUC__) || defined(__GNUG__) + result["compiler"] = {{"family", "gcc"}, {"version", std::to_string(__GNUC__) + "." + std::to_string(__GNUC_MINOR__) + "." + std::to_string(__GNUC_PATCHLEVEL__)}}; +#elif defined(__HP_cc) || defined(__HP_aCC) + result["compiler"] = "hp" +#elif defined(__IBMCPP__) + result["compiler"] = {{"family", "ilecpp"}, {"version", __IBMCPP__}}; +#elif defined(_MSC_VER) + result["compiler"] = {{"family", "msvc"}, {"version", _MSC_VER}}; +#elif defined(__PGI) + result["compiler"] = {{"family", "pgcpp"}, {"version", __PGI}}; +#elif defined(__SUNPRO_CC) + result["compiler"] = {{"family", "sunpro"}, {"version", __SUNPRO_CC}}; +#else + result["compiler"] = {{"family", "unknown"}, {"version", "unknown"}}; +#endif - /*! - @copydoc basic_json::back() - */ - const_reference back() const - { - auto tmp = cend(); - --tmp; - return *tmp; +#ifdef __cplusplus + result["compiler"]["c++"] = std::to_string(__cplusplus); +#else + result["compiler"]["c++"] = "unknown"; +#endif + return result; } - /*! - @brief remove element given an iterator - - Removes the element specified by iterator @a pos. The iterator @a pos must - be valid and dereferenceable. Thus the `end()` iterator (which is valid, - but is not dereferenceable) cannot be used as a value for @a pos. - - If called on a primitive type other than `null`, the resulting JSON value - will be `null`. - @param[in] pos iterator to the element to remove - @return Iterator following the last removed element. If the iterator @a - pos refers to the last element, the `end()` iterator is returned. + /////////////////////////// + // JSON value data types // + /////////////////////////// - @tparam IteratorType an @ref iterator or @ref const_iterator + /// @name JSON value data types + /// The data types to store a JSON value. These types are derived from + /// the template arguments passed to class @ref basic_json. + /// @{ - @post Invalidates iterators and references at or after the point of the - erase, including the `end()` iterator. +#if defined(JSON_HAS_CPP_14) + // Use transparent comparator if possible, combined with perfect forwarding + // on find() and count() calls prevents unnecessary string construction. + using object_comparator_t = std::less<>; +#else + using object_comparator_t = std::less; +#endif - @throw type_error.307 if called on a `null` value; example: `"cannot use - erase() with null"` - @throw invalid_iterator.202 if called on an iterator which does not belong - to the current JSON value; example: `"iterator does not fit current - value"` - @throw invalid_iterator.205 if called on a primitive type with invalid - iterator (i.e., any iterator which is not `begin()`); example: `"iterator - out of range"` + /*! + @brief a type for an object - @complexity The complexity depends on the type: - - objects: amortized constant - - arrays: linear in distance between @a pos and the end of the container - - strings: linear in the length of the string - - other types: constant + [RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows: + > An object is an unordered collection of zero or more name/value pairs, + > where a name is a string and a value is a string, number, boolean, null, + > object, or array. - @liveexample{The example shows the result of `erase()` for different JSON - types.,erase__IteratorType} + To store objects in C++, a type is defined by the template parameters + described below. - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key - @sa @ref erase(const size_type) -- removes the element from an array at - the given index + @tparam ObjectType the container to store objects (e.g., `std::map` or + `std::unordered_map`) + @tparam StringType the type of the keys or names (e.g., `std::string`). + The comparison function `std::less` is used to order elements + inside the container. + @tparam AllocatorType the allocator to use for objects (e.g., + `std::allocator`) - @since version 1.0.0 - */ - template::value or - std::is_same::value, int>::type - = 0> - IteratorType erase(IteratorType pos) - { - // make sure iterator fits the current value - if (this != pos.m_object) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } + #### Default type - IteratorType result = end(); + With the default values for @a ObjectType (`std::map`), @a StringType + (`std::string`), and @a AllocatorType (`std::allocator`), the default + value for @a object_t is: - switch (m_type) - { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: - { - if (not pos.m_it.primitive_iterator.is_begin()) - { - JSON_THROW(invalid_iterator::create(205, "iterator out of range")); - } + @code {.cpp} + std::map< + std::string, // key_type + basic_json, // value_type + std::less, // key_compare + std::allocator> // allocator_type + > + @endcode - if (is_string()) - { - AllocatorType alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - m_value.string = nullptr; - } + #### Behavior - m_type = value_t::null; - assert_invariant(); - break; - } + The choice of @a object_t influences the behavior of the JSON class. With + the default type, objects have the following behavior: - case value_t::object: - { - result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator); - break; - } + - When all names are unique, objects will be interoperable in the sense + that all software implementations receiving that object will agree on + the name-value mappings. + - When the names within an object are not unique, it is unspecified which + one of the values for a given key will be chosen. For instance, + `{"key": 2, "key": 1}` could be equal to either `{"key": 1}` or + `{"key": 2}`. + - Internally, name/value pairs are stored in lexicographical order of the + names. Objects will also be serialized (see @ref dump) in this order. + For instance, `{"b": 1, "a": 2}` and `{"a": 2, "b": 1}` will be stored + and serialized as `{"a": 2, "b": 1}`. + - When comparing objects, the order of the name/value pairs is irrelevant. + This makes objects interoperable in the sense that they will not be + affected by these differences. For instance, `{"b": 1, "a": 2}` and + `{"a": 2, "b": 1}` will be treated as equal. - case value_t::array: - { - result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator); - break; - } + #### Limits - default: - { - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } - } + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the maximum depth of nesting. - return result; - } + In this class, the object's limit of nesting is not explicitly constrained. + However, a maximum depth of nesting may be introduced by the compiler or + runtime environment. A theoretical limit can be queried by calling the + @ref max_size function of a JSON object. - /*! - @brief remove elements given an iterator range + #### Storage - Removes the element specified by the range `[first; last)`. The iterator - @a first does not need to be dereferenceable if `first == last`: erasing - an empty range is a no-op. + Objects are stored as pointers in a @ref basic_json type. That is, for any + access to object values, a pointer of type `object_t*` must be + dereferenced. - If called on a primitive type other than `null`, the resulting JSON value - will be `null`. + @sa @ref array_t -- type for an array value - @param[in] first iterator to the beginning of the range to remove - @param[in] last iterator past the end of the range to remove - @return Iterator following the last removed element. If the iterator @a - second refers to the last element, the `end()` iterator is returned. + @since version 1.0.0 - @tparam IteratorType an @ref iterator or @ref const_iterator + @note The order name/value pairs are added to the object is *not* + preserved by the library. Therefore, iterating an object may return + name/value pairs in a different order than they were originally stored. In + fact, keys will be traversed in alphabetical order as `std::map` with + `std::less` is used by default. Please note this behavior conforms to [RFC + 7159](http://rfc7159.net/rfc7159), because any order implements the + specified "unordered" nature of JSON objects. + */ + using object_t = ObjectType>>; - @post Invalidates iterators and references at or after the point of the - erase, including the `end()` iterator. + /*! + @brief a type for an array - @throw type_error.307 if called on a `null` value; example: `"cannot use - erase() with null"` - @throw invalid_iterator.203 if called on iterators which does not belong - to the current JSON value; example: `"iterators do not fit current value"` - @throw invalid_iterator.204 if called on a primitive type with invalid - iterators (i.e., if `first != begin()` and `last != end()`); example: - `"iterators out of range"` + [RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows: + > An array is an ordered sequence of zero or more values. - @complexity The complexity depends on the type: - - objects: `log(size()) + std::distance(first, last)` - - arrays: linear in the distance between @a first and @a last, plus linear - in the distance between @a last and end of the container - - strings: linear in the length of the string - - other types: constant + To store objects in C++, a type is defined by the template parameters + explained below. - @liveexample{The example shows the result of `erase()` for different JSON - types.,erase__IteratorType_IteratorType} + @tparam ArrayType container type to store arrays (e.g., `std::vector` or + `std::list`) + @tparam AllocatorType allocator to use for arrays (e.g., `std::allocator`) - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key - @sa @ref erase(const size_type) -- removes the element from an array at - the given index + #### Default type - @since version 1.0.0 - */ - template::value or - std::is_same::value, int>::type - = 0> - IteratorType erase(IteratorType first, IteratorType last) - { - // make sure iterator fits the current value - if (this != first.m_object or this != last.m_object) - { - JSON_THROW(invalid_iterator::create(203, "iterators do not fit current value")); - } + With the default values for @a ArrayType (`std::vector`) and @a + AllocatorType (`std::allocator`), the default value for @a array_t is: - IteratorType result = end(); + @code {.cpp} + std::vector< + basic_json, // value_type + std::allocator // allocator_type + > + @endcode - switch (m_type) - { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: - { - if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end()) - { - JSON_THROW(invalid_iterator::create(204, "iterators out of range")); - } + #### Limits - if (is_string()) - { - AllocatorType alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - m_value.string = nullptr; - } + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the maximum depth of nesting. - m_type = value_t::null; - assert_invariant(); - break; - } + In this class, the array's limit of nesting is not explicitly constrained. + However, a maximum depth of nesting may be introduced by the compiler or + runtime environment. A theoretical limit can be queried by calling the + @ref max_size function of a JSON array. - case value_t::object: - { - result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator, - last.m_it.object_iterator); - break; - } + #### Storage - case value_t::array: - { - result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator, - last.m_it.array_iterator); - break; - } + Arrays are stored as pointers in a @ref basic_json type. That is, for any + access to array values, a pointer of type `array_t*` must be dereferenced. - default: - { - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } - } + @sa @ref object_t -- type for an object value - return result; - } + @since version 1.0.0 + */ + using array_t = ArrayType>; /*! - @brief remove element from a JSON object given a key + @brief a type for a string - Removes elements from a JSON object with the key value @a key. + [RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows: + > A string is a sequence of zero or more Unicode characters. - @param[in] key value of the elements to remove + To store objects in C++, a type is defined by the template parameter + described below. Unicode values are split by the JSON class into + byte-sized characters during deserialization. - @return Number of elements removed. If @a ObjectType is the default - `std::map` type, the return value will always be `0` (@a key was not - found) or `1` (@a key was found). + @tparam StringType the container to store strings (e.g., `std::string`). + Note this container is used for keys/names in objects, see @ref object_t. - @post References and iterators to the erased elements are invalidated. - Other references and iterators are not affected. + #### Default type - @throw type_error.307 when called on a type other than JSON object; - example: `"cannot use erase() with null"` + With the default values for @a StringType (`std::string`), the default + value for @a string_t is: - @complexity `log(size()) + count(key)` + @code {.cpp} + std::string + @endcode - @liveexample{The example shows the effect of `erase()`.,erase__key_type} + #### Encoding - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const size_type) -- removes the element from an array at - the given index + Strings are stored in UTF-8 encoding. Therefore, functions like + `std::string::size()` or `std::string::length()` return the number of + bytes in the string rather than the number of characters or glyphs. - @since version 1.0.0 - */ - size_type erase(const typename object_t::key_type& key) - { - // this erase only works for objects - if (is_object()) - { - return m_value.object->erase(key); - } + #### String comparison - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } + [RFC 7159](http://rfc7159.net/rfc7159) states: + > Software implementations are typically required to test names of object + > members for equality. Implementations that transform the textual + > representation into sequences of Unicode code units and then perform the + > comparison numerically, code unit by code unit, are interoperable in the + > sense that implementations will agree in all cases on equality or + > inequality of two strings. For example, implementations that compare + > strings with escaped characters unconverted may incorrectly find that + > `"a\\b"` and `"a\u005Cb"` are not equal. - /*! - @brief remove element from a JSON array given an index + This implementation is interoperable as it does compare strings code unit + by code unit. - Removes element from a JSON array at the index @a idx. + #### Storage - @param[in] idx index of the element to remove + String values are stored as pointers in a @ref basic_json type. That is, + for any access to string values, a pointer of type `string_t*` must be + dereferenced. - @throw type_error.307 when called on a type other than JSON object; - example: `"cannot use erase() with null"` - @throw out_of_range.401 when `idx >= size()`; example: `"array index 17 - is out of range"` + @since version 1.0.0 + */ + using string_t = StringType; - @complexity Linear in distance between @a idx and the end of the container. + /*! + @brief a type for a boolean - @liveexample{The example shows the effect of `erase()`.,erase__size_type} + [RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a + type which differentiates the two literals `true` and `false`. - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key + To store objects in C++, a type is defined by the template parameter @a + BooleanType which chooses the type to use. - @since version 1.0.0 - */ - void erase(const size_type idx) - { - // this erase only works for arrays - if (is_array()) - { - if (idx >= size()) - { - JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); - } + #### Default type - m_value.array->erase(m_value.array->begin() + static_cast(idx)); - } - else - { - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } - } + With the default values for @a BooleanType (`bool`), the default value for + @a boolean_t is: - /// @} + @code {.cpp} + bool + @endcode + #### Storage - //////////// - // lookup // - //////////// + Boolean values are stored directly inside a @ref basic_json type. - /// @name lookup - /// @{ + @since version 1.0.0 + */ + using boolean_t = BooleanType; /*! - @brief find an element in a JSON object + @brief a type for a number (integer) - Finds an element in a JSON object with key equivalent to @a key. If the - element is not found or the JSON value is not an object, end() is - returned. + [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: + > The representation of numbers is similar to that used in most + > programming languages. A number is represented in base 10 using decimal + > digits. It contains an integer component that may be prefixed with an + > optional minus sign, which may be followed by a fraction part and/or an + > exponent part. Leading zeros are not allowed. (...) Numeric values that + > cannot be represented in the grammar below (such as Infinity and NaN) + > are not permitted. - @note This method always returns @ref end() when executed on a JSON type - that is not an object. + This description includes both integer and floating-point numbers. + However, C++ allows more precise storage if it is known whether the number + is a signed integer, an unsigned integer or a floating-point number. + Therefore, three different types, @ref number_integer_t, @ref + number_unsigned_t and @ref number_float_t are used. - @param[in] key key value of the element to search for + To store integer numbers in C++, a type is defined by the template + parameter @a NumberIntegerType which chooses the type to use. - @return Iterator to an element with key equivalent to @a key. If no such - element is found or the JSON value is not an object, past-the-end (see - @ref end()) iterator is returned. + #### Default type - @complexity Logarithmic in the size of the JSON object. + With the default values for @a NumberIntegerType (`int64_t`), the default + value for @a number_integer_t is: - @liveexample{The example shows how `find()` is used.,find__key_type} + @code {.cpp} + int64_t + @endcode - @since version 1.0.0 - */ - iterator find(typename object_t::key_type key) - { - auto result = end(); + #### Default behavior - if (is_object()) - { - result.m_it.object_iterator = m_value.object->find(key); - } + - The restrictions about leading zeros is not enforced in C++. Instead, + leading zeros in integer literals lead to an interpretation as octal + number. Internally, the value will be stored as decimal number. For + instance, the C++ integer literal `010` will be serialized to `8`. + During deserialization, leading zeros yield an error. + - Not-a-number (NaN) values will be serialized to `null`. - return result; - } + #### Limits - /*! - @brief find an element in a JSON object - @copydoc find(typename object_t::key_type) - */ - const_iterator find(typename object_t::key_type key) const - { - auto result = cend(); + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the range and precision of numbers. - if (is_object()) - { - result.m_it.object_iterator = m_value.object->find(key); - } + When the default type is used, the maximal integer number that can be + stored is `9223372036854775807` (INT64_MAX) and the minimal integer number + that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers + that are out of range will yield over/underflow when used in a + constructor. During deserialization, too large or small integer numbers + will be automatically be stored as @ref number_unsigned_t or @ref + number_float_t. - return result; - } + [RFC 7159](http://rfc7159.net/rfc7159) further states: + > Note that when such software is used, numbers that are integers and are + > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense + > that implementations will agree exactly on their numeric values. - /*! - @brief returns the number of occurrences of a key in a JSON object + As this range is a subrange of the exactly supported range [INT64_MIN, + INT64_MAX], this class's integer type is interoperable. - Returns the number of elements with key @a key. If ObjectType is the - default `std::map` type, the return value will always be `0` (@a key was - not found) or `1` (@a key was found). + #### Storage - @note This method always returns `0` when executed on a JSON type that is - not an object. + Integer number values are stored directly inside a @ref basic_json type. - @param[in] key key value of the element to count + @sa @ref number_float_t -- type for number values (floating-point) - @return Number of elements with key @a key. If the JSON value is not an - object, the return value will be `0`. + @sa @ref number_unsigned_t -- type for number values (unsigned integer) - @complexity Logarithmic in the size of the JSON object. + @since version 1.0.0 + */ + using number_integer_t = NumberIntegerType; + + /*! + @brief a type for a number (unsigned) + + [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: + > The representation of numbers is similar to that used in most + > programming languages. A number is represented in base 10 using decimal + > digits. It contains an integer component that may be prefixed with an + > optional minus sign, which may be followed by a fraction part and/or an + > exponent part. Leading zeros are not allowed. (...) Numeric values that + > cannot be represented in the grammar below (such as Infinity and NaN) + > are not permitted. - @liveexample{The example shows how `count()` is used.,count} + This description includes both integer and floating-point numbers. + However, C++ allows more precise storage if it is known whether the number + is a signed integer, an unsigned integer or a floating-point number. + Therefore, three different types, @ref number_integer_t, @ref + number_unsigned_t and @ref number_float_t are used. - @since version 1.0.0 - */ - size_type count(typename object_t::key_type key) const - { - // return 0 for all nonobject types - return is_object() ? m_value.object->count(key) : 0; - } + To store unsigned integer numbers in C++, a type is defined by the + template parameter @a NumberUnsignedType which chooses the type to use. - /// @} + #### Default type + With the default values for @a NumberUnsignedType (`uint64_t`), the + default value for @a number_unsigned_t is: - /////////////// - // iterators // - /////////////// + @code {.cpp} + uint64_t + @endcode - /// @name iterators - /// @{ + #### Default behavior - /*! - @brief returns an iterator to the first element + - The restrictions about leading zeros is not enforced in C++. Instead, + leading zeros in integer literals lead to an interpretation as octal + number. Internally, the value will be stored as decimal number. For + instance, the C++ integer literal `010` will be serialized to `8`. + During deserialization, leading zeros yield an error. + - Not-a-number (NaN) values will be serialized to `null`. - Returns an iterator to the first element. + #### Limits - @image html range-begin-end.svg "Illustration from cppreference.com" + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the range and precision of numbers. - @return iterator to the first element + When the default type is used, the maximal integer number that can be + stored is `18446744073709551615` (UINT64_MAX) and the minimal integer + number that can be stored is `0`. Integer numbers that are out of range + will yield over/underflow when used in a constructor. During + deserialization, too large or small integer numbers will be automatically + be stored as @ref number_integer_t or @ref number_float_t. - @complexity Constant. + [RFC 7159](http://rfc7159.net/rfc7159) further states: + > Note that when such software is used, numbers that are integers and are + > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense + > that implementations will agree exactly on their numeric values. - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. + As this range is a subrange (when considered in conjunction with the + number_integer_t type) of the exactly supported range [0, UINT64_MAX], + this class's integer type is interoperable. - @liveexample{The following code shows an example for `begin()`.,begin} + #### Storage - @sa @ref cbegin() -- returns a const iterator to the beginning - @sa @ref end() -- returns an iterator to the end - @sa @ref cend() -- returns a const iterator to the end + Integer number values are stored directly inside a @ref basic_json type. - @since version 1.0.0 - */ - iterator begin() noexcept - { - iterator result(this); - result.set_begin(); - return result; - } + @sa @ref number_float_t -- type for number values (floating-point) + @sa @ref number_integer_t -- type for number values (integer) - /*! - @copydoc basic_json::cbegin() + @since version 2.0.0 */ - const_iterator begin() const noexcept - { - return cbegin(); - } + using number_unsigned_t = NumberUnsignedType; /*! - @brief returns a const iterator to the first element - - Returns a const iterator to the first element. + @brief a type for a number (floating-point) - @image html range-begin-end.svg "Illustration from cppreference.com" + [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: + > The representation of numbers is similar to that used in most + > programming languages. A number is represented in base 10 using decimal + > digits. It contains an integer component that may be prefixed with an + > optional minus sign, which may be followed by a fraction part and/or an + > exponent part. Leading zeros are not allowed. (...) Numeric values that + > cannot be represented in the grammar below (such as Infinity and NaN) + > are not permitted. - @return const iterator to the first element + This description includes both integer and floating-point numbers. + However, C++ allows more precise storage if it is known whether the number + is a signed integer, an unsigned integer or a floating-point number. + Therefore, three different types, @ref number_integer_t, @ref + number_unsigned_t and @ref number_float_t are used. - @complexity Constant. + To store floating-point numbers in C++, a type is defined by the template + parameter @a NumberFloatType which chooses the type to use. - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).begin()`. + #### Default type - @liveexample{The following code shows an example for `cbegin()`.,cbegin} + With the default values for @a NumberFloatType (`double`), the default + value for @a number_float_t is: - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref end() -- returns an iterator to the end - @sa @ref cend() -- returns a const iterator to the end + @code {.cpp} + double + @endcode - @since version 1.0.0 - */ - const_iterator cbegin() const noexcept - { - const_iterator result(this); - result.set_begin(); - return result; - } + #### Default behavior - /*! - @brief returns an iterator to one past the last element + - The restrictions about leading zeros is not enforced in C++. Instead, + leading zeros in floating-point literals will be ignored. Internally, + the value will be stored as decimal number. For instance, the C++ + floating-point literal `01.2` will be serialized to `1.2`. During + deserialization, leading zeros yield an error. + - Not-a-number (NaN) values will be serialized to `null`. - Returns an iterator to one past the last element. + #### Limits - @image html range-begin-end.svg "Illustration from cppreference.com" + [RFC 7159](http://rfc7159.net/rfc7159) states: + > This specification allows implementations to set limits on the range and + > precision of numbers accepted. Since software that implements IEEE + > 754-2008 binary64 (double precision) numbers is generally available and + > widely used, good interoperability can be achieved by implementations + > that expect no more precision or range than these provide, in the sense + > that implementations will approximate JSON numbers within the expected + > precision. - @return iterator one past the last element + This implementation does exactly follow this approach, as it uses double + precision floating-point numbers. Note values smaller than + `-1.79769313486232e+308` and values greater than `1.79769313486232e+308` + will be stored as NaN internally and be serialized to `null`. - @complexity Constant. + #### Storage - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. + Floating-point number values are stored directly inside a @ref basic_json + type. - @liveexample{The following code shows an example for `end()`.,end} + @sa @ref number_integer_t -- type for number values (integer) - @sa @ref cend() -- returns a const iterator to the end - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref cbegin() -- returns a const iterator to the beginning + @sa @ref number_unsigned_t -- type for number values (unsigned integer) @since version 1.0.0 */ - iterator end() noexcept - { - iterator result(this); - result.set_end(); - return result; - } + using number_float_t = NumberFloatType; - /*! - @copydoc basic_json::cend() - */ - const_iterator end() const noexcept + /// @} + + private: + + /// helper for exception-safe object creation + template + static T* create(Args&& ... args) { - return cend(); + AllocatorType alloc; + using AllocatorTraits = std::allocator_traits>; + + auto deleter = [&](T * object) + { + AllocatorTraits::deallocate(alloc, object, 1); + }; + std::unique_ptr object(AllocatorTraits::allocate(alloc, 1), deleter); + AllocatorTraits::construct(alloc, object.get(), std::forward(args)...); + assert(object != nullptr); + return object.release(); } + //////////////////////// + // JSON value storage // + //////////////////////// + /*! - @brief returns a const iterator to one past the last element + @brief a JSON value - Returns a const iterator to one past the last element. + The actual storage for a JSON value of the @ref basic_json class. This + union combines the different storage types for the JSON value types + defined in @ref value_t. - @image html range-begin-end.svg "Illustration from cppreference.com" + JSON type | value_t type | used type + --------- | --------------- | ------------------------ + object | object | pointer to @ref object_t + array | array | pointer to @ref array_t + string | string | pointer to @ref string_t + boolean | boolean | @ref boolean_t + number | number_integer | @ref number_integer_t + number | number_unsigned | @ref number_unsigned_t + number | number_float | @ref number_float_t + null | null | *no value is stored* - @return const iterator one past the last element + @note Variable-length types (objects, arrays, and strings) are stored as + pointers. The size of the union should not exceed 64 bits if the default + value types are used. - @complexity Constant. + @since version 1.0.0 + */ + union json_value + { + /// object (stored with pointer to save storage) + object_t* object; + /// array (stored with pointer to save storage) + array_t* array; + /// string (stored with pointer to save storage) + string_t* string; + /// boolean + boolean_t boolean; + /// number (integer) + number_integer_t number_integer; + /// number (unsigned integer) + number_unsigned_t number_unsigned; + /// number (floating-point) + number_float_t number_float; - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).end()`. + /// default constructor (for null values) + json_value() = default; + /// constructor for booleans + json_value(boolean_t v) noexcept : boolean(v) {} + /// constructor for numbers (integer) + json_value(number_integer_t v) noexcept : number_integer(v) {} + /// constructor for numbers (unsigned) + json_value(number_unsigned_t v) noexcept : number_unsigned(v) {} + /// constructor for numbers (floating-point) + json_value(number_float_t v) noexcept : number_float(v) {} + /// constructor for empty values of a given type + json_value(value_t t) + { + switch (t) + { + case value_t::object: + { + object = create(); + break; + } - @liveexample{The following code shows an example for `cend()`.,cend} + case value_t::array: + { + array = create(); + break; + } - @sa @ref end() -- returns an iterator to the end - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref cbegin() -- returns a const iterator to the beginning + case value_t::string: + { + string = create(""); + break; + } - @since version 1.0.0 - */ - const_iterator cend() const noexcept - { - const_iterator result(this); - result.set_end(); - return result; - } + case value_t::boolean: + { + boolean = boolean_t(false); + break; + } - /*! - @brief returns an iterator to the reverse-beginning + case value_t::number_integer: + { + number_integer = number_integer_t(0); + break; + } - Returns an iterator to the reverse-beginning; that is, the last element. + case value_t::number_unsigned: + { + number_unsigned = number_unsigned_t(0); + break; + } - @image html range-rbegin-rend.svg "Illustration from cppreference.com" + case value_t::number_float: + { + number_float = number_float_t(0.0); + break; + } - @complexity Constant. + case value_t::null: + { + object = nullptr; // silence warning, see #821 + break; + } - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `reverse_iterator(end())`. + default: + { + object = nullptr; // silence warning, see #821 + if (JSON_UNLIKELY(t == value_t::null)) + { + JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 3.1.2")); // LCOV_EXCL_LINE + } + break; + } + } + } - @liveexample{The following code shows an example for `rbegin()`.,rbegin} + /// constructor for strings + json_value(const string_t& value) + { + string = create(value); + } - @sa @ref crbegin() -- returns a const reverse iterator to the beginning - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref crend() -- returns a const reverse iterator to the end + /// constructor for rvalue strings + json_value(string_t&& value) + { + string = create(std::move(value)); + } - @since version 1.0.0 - */ - reverse_iterator rbegin() noexcept - { - return reverse_iterator(end()); - } + /// constructor for objects + json_value(const object_t& value) + { + object = create(value); + } - /*! - @copydoc basic_json::crbegin() - */ - const_reverse_iterator rbegin() const noexcept - { - return crbegin(); - } + /// constructor for rvalue objects + json_value(object_t&& value) + { + object = create(std::move(value)); + } - /*! - @brief returns an iterator to the reverse-end + /// constructor for arrays + json_value(const array_t& value) + { + array = create(value); + } - Returns an iterator to the reverse-end; that is, one before the first - element. + /// constructor for rvalue arrays + json_value(array_t&& value) + { + array = create(std::move(value)); + } - @image html range-rbegin-rend.svg "Illustration from cppreference.com" + void destroy(value_t t) noexcept + { + switch (t) + { + case value_t::object: + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, object); + std::allocator_traits::deallocate(alloc, object, 1); + break; + } - @complexity Constant. + case value_t::array: + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, array); + std::allocator_traits::deallocate(alloc, array, 1); + break; + } - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `reverse_iterator(begin())`. + case value_t::string: + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, string); + std::allocator_traits::deallocate(alloc, string, 1); + break; + } - @liveexample{The following code shows an example for `rend()`.,rend} + default: + { + break; + } + } + } + }; - @sa @ref crend() -- returns a const reverse iterator to the end - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref crbegin() -- returns a const reverse iterator to the beginning + /*! + @brief checks the class invariants - @since version 1.0.0 + This function asserts the class invariants. It needs to be called at the + end of every constructor to make sure that created objects respect the + invariant. Furthermore, it has to be called each time the type of a JSON + value is changed, because the invariant expresses a relationship between + @a m_type and @a m_value. */ - reverse_iterator rend() noexcept + void assert_invariant() const noexcept { - return reverse_iterator(begin()); + assert(m_type != value_t::object or m_value.object != nullptr); + assert(m_type != value_t::array or m_value.array != nullptr); + assert(m_type != value_t::string or m_value.string != nullptr); } - /*! - @copydoc basic_json::crend() - */ - const_reverse_iterator rend() const noexcept - { - return crend(); - } + public: + ////////////////////////// + // JSON parser callback // + ////////////////////////// /*! - @brief returns a const reverse iterator to the last element - - Returns a const iterator to the reverse-beginning; that is, the last - element. - - @image html range-rbegin-rend.svg "Illustration from cppreference.com" - - @complexity Constant. + @brief parser event types - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).rbegin()`. - - @liveexample{The following code shows an example for `crbegin()`.,crbegin} + The parser callback distinguishes the following events: + - `object_start`: the parser read `{` and started to process a JSON object + - `key`: the parser read a key of a value in an object + - `object_end`: the parser read `}` and finished processing a JSON object + - `array_start`: the parser read `[` and started to process a JSON array + - `array_end`: the parser read `]` and finished processing a JSON array + - `value`: the parser finished reading a JSON value - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref crend() -- returns a const reverse iterator to the end + @image html callback_events.png "Example when certain parse events are triggered" - @since version 1.0.0 + @sa @ref parser_callback_t for more information and examples */ - const_reverse_iterator crbegin() const noexcept - { - return const_reverse_iterator(cend()); - } + using parse_event_t = typename parser::parse_event_t; /*! - @brief returns a const reverse iterator to one before the first - - Returns a const reverse iterator to the reverse-end; that is, one before - the first element. + @brief per-element parser callback type - @image html range-rbegin-rend.svg "Illustration from cppreference.com" + With a parser callback function, the result of parsing a JSON text can be + influenced. When passed to @ref parse, it is called on certain events + (passed as @ref parse_event_t via parameter @a event) with a set recursion + depth @a depth and context JSON value @a parsed. The return value of the + callback function is a boolean indicating whether the element that emitted + the callback shall be kept or not. - @complexity Constant. + We distinguish six scenarios (determined by the event type) in which the + callback function can be called. The following table describes the values + of the parameters @a depth, @a event, and @a parsed. - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).rend()`. + parameter @a event | description | parameter @a depth | parameter @a parsed + ------------------ | ----------- | ------------------ | ------------------- + parse_event_t::object_start | the parser read `{` and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded + parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key + parse_event_t::object_end | the parser read `}` and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object + parse_event_t::array_start | the parser read `[` and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded + parse_event_t::array_end | the parser read `]` and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array + parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value - @liveexample{The following code shows an example for `crend()`.,crend} + @image html callback_events.png "Example when certain parse events are triggered" - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref crbegin() -- returns a const reverse iterator to the beginning + Discarding a value (i.e., returning `false`) has different effects + depending on the context in which function was called: - @since version 1.0.0 - */ - const_reverse_iterator crend() const noexcept - { - return const_reverse_iterator(cbegin()); - } + - Discarded values in structured types are skipped. That is, the parser + will behave as if the discarded value was never read. + - In case a value outside a structured type is skipped, it is replaced + with `null`. This case happens if the top-level element is skipped. - private: - // forward declaration - template class iteration_proxy; + @param[in] depth the depth of the recursion during parsing - public: - /*! - @brief wrapper to access iterator member functions in range-based for + @param[in] event an event of type parse_event_t indicating the context in + the callback function has been called - This function allows to access @ref iterator::key() and @ref - iterator::value() during range-based for loops. In these loops, a - reference to the JSON values is returned, so there is no access to the - underlying iterator. + @param[in,out] parsed the current intermediate parse result; note that + writing to this value has no effect for parse_event_t::key events - @liveexample{The following code shows how the wrapper is used,iterator_wrapper} + @return Whether the JSON value which called the function during parsing + should be kept (`true`) or not (`false`). In the latter case, it is either + skipped completely or replaced by an empty discarded object. - @note The name of this function is not yet final and may change in the - future. - */ - static iteration_proxy iterator_wrapper(reference cont) - { - return iteration_proxy(cont); - } + @sa @ref parse for examples - /*! - @copydoc iterator_wrapper(reference) + @since version 1.0.0 */ - static iteration_proxy iterator_wrapper(const_reference cont) - { - return iteration_proxy(cont); - } - - /// @} + using parser_callback_t = typename parser::parser_callback_t; + using json_sax_t = typename parser::json_sax_t; - ////////////// - // capacity // - ////////////// + ////////////////// + // constructors // + ////////////////// - /// @name capacity + /// @name constructors and destructors + /// Constructors of class @ref basic_json, copy/move constructor, copy + /// assignment, static functions creating objects, and the destructor. /// @{ /*! - @brief checks whether the container is empty + @brief create an empty value with a given type - Checks if a JSON value has no elements. + Create an empty JSON value with a given type. The value will be default + initialized with an empty value which depends on the type: - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `true` - boolean | `false` - string | `false` - number | `false` - object | result of function `object_t::empty()` - array | result of function `array_t::empty()` + Value type | initial value + ----------- | ------------- + null | `null` + boolean | `false` + string | `""` + number | `0` + object | `{}` + array | `[]` - @note This function does not return whether a string stored as JSON value - is empty - it returns whether the JSON container itself is empty which is - false in the case of a string. + @param[in] v the type of the value to create - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their `empty()` functions have constant - complexity. + @complexity Constant. - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `begin() == end()`. + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @liveexample{The following code uses `empty()` to check if a JSON - object contains any elements.,empty} + @liveexample{The following code shows the constructor for different @ref + value_t values,basic_json__value_t} - @sa @ref size() -- returns the number of elements + @sa @ref clear() -- restores the postcondition of this constructor @since version 1.0.0 */ - bool empty() const noexcept + basic_json(const value_t v) + : m_type(v), m_value(v) { - switch (m_type) - { - case value_t::null: - { - // null values are empty - return true; - } - - case value_t::array: - { - // delegate call to array_t::empty() - return m_value.array->empty(); - } - - case value_t::object: - { - // delegate call to object_t::empty() - return m_value.object->empty(); - } - - default: - { - // all other types are nonempty - return false; - } - } + assert_invariant(); } /*! - @brief returns the number of elements - - Returns the number of elements in a JSON value. - - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `0` - boolean | `1` - string | `1` - number | `1` - object | result of function object_t::size() - array | result of function array_t::size() - - @note This function does not return the length of a string stored as JSON - value - it returns the number of elements in the JSON value which is 1 in - the case of a string. + @brief create a null object - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their size() functions have constant - complexity. + Create a `null` JSON value. It either takes a null pointer as parameter + (explicitly creating `null`) or no parameter (implicitly creating `null`). + The passed null pointer itself is not read -- it is only used to choose + the right constructor. - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `std::distance(begin(), end())`. + @complexity Constant. - @liveexample{The following code calls `size()` on the different value - types.,size} + @exceptionsafety No-throw guarantee: this constructor never throws + exceptions. - @sa @ref empty() -- checks whether the container is empty - @sa @ref max_size() -- returns the maximal number of elements + @liveexample{The following code shows the constructor with and without a + null pointer parameter.,basic_json__nullptr_t} @since version 1.0.0 */ - size_type size() const noexcept + basic_json(std::nullptr_t = nullptr) noexcept + : basic_json(value_t::null) { - switch (m_type) - { - case value_t::null: - { - // null values are empty - return 0; - } + assert_invariant(); + } - case value_t::array: - { - // delegate call to array_t::size() - return m_value.array->size(); - } + /*! + @brief create a JSON value - case value_t::object: - { - // delegate call to object_t::size() - return m_value.object->size(); - } + This is a "catch all" constructor for all compatible JSON types; that is, + types for which a `to_json()` method exists. The constructor forwards the + parameter @a val to that method (to `json_serializer::to_json` method + with `U = uncvref_t`, to be exact). - default: - { - // all other types have size 1 - return 1; - } - } - } + Template type @a CompatibleType includes, but is not limited to, the + following types: + - **arrays**: @ref array_t and all kinds of compatible containers such as + `std::vector`, `std::deque`, `std::list`, `std::forward_list`, + `std::array`, `std::valarray`, `std::set`, `std::unordered_set`, + `std::multiset`, and `std::unordered_multiset` with a `value_type` from + which a @ref basic_json value can be constructed. + - **objects**: @ref object_t and all kinds of compatible associative + containers such as `std::map`, `std::unordered_map`, `std::multimap`, + and `std::unordered_multimap` with a `key_type` compatible to + @ref string_t and a `value_type` from which a @ref basic_json value can + be constructed. + - **strings**: @ref string_t, string literals, and all compatible string + containers can be used. + - **numbers**: @ref number_integer_t, @ref number_unsigned_t, + @ref number_float_t, and all convertible number types such as `int`, + `size_t`, `int64_t`, `float` or `double` can be used. + - **boolean**: @ref boolean_t / `bool` can be used. - /*! - @brief returns the maximum possible number of elements + See the examples below. - Returns the maximum number of elements a JSON value is able to hold due to - system or library implementation limitations, i.e. `std::distance(begin(), - end())` for the JSON value. + @tparam CompatibleType a type such that: + - @a CompatibleType is not derived from `std::istream`, + - @a CompatibleType is not @ref basic_json (to avoid hijacking copy/move + constructors), + - @a CompatibleType is not a different @ref basic_json type (i.e. with different template arguments) + - @a CompatibleType is not a @ref basic_json nested type (e.g., + @ref json_pointer, @ref iterator, etc ...) + - @ref @ref json_serializer has a + `to_json(basic_json_t&, CompatibleType&&)` method - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `0` (same as `size()`) - boolean | `1` (same as `size()`) - string | `1` (same as `size()`) - number | `1` (same as `size()`) - object | result of function `object_t::max_size()` - array | result of function `array_t::max_size()` + @tparam U = `uncvref_t` - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their `max_size()` functions have constant - complexity. + @param[in] val the value to be forwarded to the respective constructor - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of returning `b.size()` where `b` is the largest - possible JSON value. + @complexity Usually linear in the size of the passed @a val, also + depending on the implementation of the called `to_json()` + method. - @liveexample{The following code calls `max_size()` on the different value - types. Note the output is implementation specific.,max_size} + @exceptionsafety Depends on the called constructor. For types directly + supported by the library (i.e., all types for which no `to_json()` function + was provided), strong guarantee holds: if an exception is thrown, there are + no changes to any JSON value. - @sa @ref size() -- returns the number of elements + @liveexample{The following code shows the constructor with several + compatible types.,basic_json__CompatibleType} - @since version 1.0.0 + @since version 2.1.0 */ - size_type max_size() const noexcept + template , + detail::enable_if_t< + detail::is_compatible_type::value, int> = 0> + basic_json(CompatibleType && val) noexcept(noexcept( + JSONSerializer::to_json(std::declval(), + std::forward(val)))) { - switch (m_type) - { - case value_t::array: - { - // delegate call to array_t::max_size() - return m_value.array->max_size(); - } - - case value_t::object: - { - // delegate call to object_t::max_size() - return m_value.object->max_size(); - } - - default: - { - // all other types have max_size() == size() - return size(); - } - } + JSONSerializer::to_json(*this, std::forward(val)); + assert_invariant(); } - /// @} - - - /////////////// - // modifiers // - /////////////// + /*! + @brief create a JSON value from an existing one - /// @name modifiers - /// @{ + This is a constructor for existing @ref basic_json types. + It does not hijack copy/move constructors, since the parameter has different + template arguments than the current ones. - /*! - @brief clears the contents + The constructor tries to convert the internal @ref m_value of the parameter. - Clears the content of a JSON value and resets it to the default value as - if @ref basic_json(value_t) would have been called: + @tparam BasicJsonType a type such that: + - @a BasicJsonType is a @ref basic_json type. + - @a BasicJsonType has different template arguments than @ref basic_json_t. - Value type | initial value - ----------- | ------------- - null | `null` - boolean | `false` - string | `""` - number | `0` - object | `{}` - array | `[]` + @param[in] val the @ref basic_json value to be converted. - @complexity Linear in the size of the JSON value. + @complexity Usually linear in the size of the passed @a val, also + depending on the implementation of the called `to_json()` + method. - @liveexample{The example below shows the effect of `clear()` to different - JSON types.,clear} + @exceptionsafety Depends on the called constructor. For types directly + supported by the library (i.e., all types for which no `to_json()` function + was provided), strong guarantee holds: if an exception is thrown, there are + no changes to any JSON value. - @since version 1.0.0 + @since version 3.1.2 */ - void clear() noexcept + template ::value and not std::is_same::value, int> = 0> + basic_json(const BasicJsonType& val) { - switch (m_type) - { - case value_t::number_integer: - { - m_value.number_integer = 0; - break; - } + using other_boolean_t = typename BasicJsonType::boolean_t; + using other_number_float_t = typename BasicJsonType::number_float_t; + using other_number_integer_t = typename BasicJsonType::number_integer_t; + using other_number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using other_string_t = typename BasicJsonType::string_t; + using other_object_t = typename BasicJsonType::object_t; + using other_array_t = typename BasicJsonType::array_t; - case value_t::number_unsigned: - { - m_value.number_unsigned = 0; + switch (val.type()) + { + case value_t::boolean: + JSONSerializer::to_json(*this, val.template get()); break; - } - case value_t::number_float: - { - m_value.number_float = 0.0; + JSONSerializer::to_json(*this, val.template get()); break; - } - - case value_t::boolean: - { - m_value.boolean = false; + case value_t::number_integer: + JSONSerializer::to_json(*this, val.template get()); + break; + case value_t::number_unsigned: + JSONSerializer::to_json(*this, val.template get()); break; - } - case value_t::string: - { - m_value.string->clear(); + JSONSerializer::to_json(*this, val.template get_ref()); + break; + case value_t::object: + JSONSerializer::to_json(*this, val.template get_ref()); break; - } - case value_t::array: - { - m_value.array->clear(); + JSONSerializer::to_json(*this, val.template get_ref()); break; - } - - case value_t::object: - { - m_value.object->clear(); + case value_t::null: + *this = nullptr; break; - } - - default: - { + case value_t::discarded: + m_type = value_t::discarded; break; - } } + assert_invariant(); } /*! - @brief add an object to an array + @brief create a container (array or object) from an initializer list - Appends the given element @a val to the end of the JSON value. If the - function is called on a JSON null value, an empty array is created before - appending @a val. + Creates a JSON value of type array or object from the passed initializer + list @a init. In case @a type_deduction is `true` (default), the type of + the JSON value to be created is deducted from the initializer list @a init + according to the following rules: - @param[in] val the value to add to the JSON array + 1. If the list is empty, an empty JSON object value `{}` is created. + 2. If the list consists of pairs whose first element is a string, a JSON + object value is created where the first elements of the pairs are + treated as keys and the second elements are as values. + 3. In all other cases, an array is created. - @throw type_error.308 when called on a type other than JSON array or - null; example: `"cannot use push_back() with number"` + The rules aim to create the best fit between a C++ initializer list and + JSON values. The rationale is as follows: - @complexity Amortized constant. + 1. The empty initializer list is written as `{}` which is exactly an empty + JSON object. + 2. C++ has no way of describing mapped types other than to list a list of + pairs. As JSON requires that keys must be of type string, rule 2 is the + weakest constraint one can pose on initializer lists to interpret them + as an object. + 3. In all other cases, the initializer list could not be interpreted as + JSON object type, so interpreting it as JSON array type is safe. - @liveexample{The example shows how `push_back()` and `+=` can be used to - add elements to a JSON array. Note how the `null` value was silently - converted to a JSON array.,push_back} + With the rules described above, the following JSON values cannot be + expressed by an initializer list: + + - the empty array (`[]`): use @ref array(initializer_list_t) + with an empty initializer list in this case + - arrays whose elements satisfy rule 2: use @ref + array(initializer_list_t) with the same initializer list + in this case + + @note When used without parentheses around an empty initializer list, @ref + basic_json() is called instead of this function, yielding the JSON null + value. + + @param[in] init initializer list with JSON values + + @param[in] type_deduction internal parameter; when set to `true`, the type + of the JSON value is deducted from the initializer list @a init; when set + to `false`, the type provided via @a manual_type is forced. This mode is + used by the functions @ref array(initializer_list_t) and + @ref object(initializer_list_t). + + @param[in] manual_type internal parameter; when @a type_deduction is set + to `false`, the created JSON value will use the provided type (only @ref + value_t::array and @ref value_t::object are valid); when @a type_deduction + is set to `true`, this parameter has no effect + + @throw type_error.301 if @a type_deduction is `false`, @a manual_type is + `value_t::object`, but @a init contains an element which is not a pair + whose first element is a string. In this case, the constructor could not + create an object. If @a type_deduction would have be `true`, an array + would have been created. See @ref object(initializer_list_t) + for an example. + + @complexity Linear in the size of the initializer list @a init. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. + + @liveexample{The example below shows how JSON values are created from + initializer lists.,basic_json__list_init_t} + + @sa @ref array(initializer_list_t) -- create a JSON array + value from an initializer list + @sa @ref object(initializer_list_t) -- create a JSON object + value from an initializer list @since version 1.0.0 */ - void push_back(basic_json&& val) + basic_json(initializer_list_t init, + bool type_deduction = true, + value_t manual_type = value_t::array) { - // push_back only works for null objects or arrays - if (not(is_null() or is_array())) + // check if each element is an array with two elements whose first + // element is a string + bool is_an_object = std::all_of(init.begin(), init.end(), + [](const detail::json_ref& element_ref) { - JSON_THROW(type_error::create(308, "cannot use push_back() with " + type_name())); - } + return (element_ref->is_array() and element_ref->size() == 2 and (*element_ref)[0].is_string()); + }); - // transform null object into an array - if (is_null()) + // adjust type if type deduction is not wanted + if (not type_deduction) { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } - - // add element to array (move semantics) - m_value.array->push_back(std::move(val)); - // invalidate object - val.m_type = value_t::null; - } + // if array is wanted, do not create an object though possible + if (manual_type == value_t::array) + { + is_an_object = false; + } - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - reference operator+=(basic_json&& val) - { - push_back(std::move(val)); - return *this; - } + // if object is wanted but impossible, throw an exception + if (JSON_UNLIKELY(manual_type == value_t::object and not is_an_object)) + { + JSON_THROW(type_error::create(301, "cannot create object from initializer list")); + } + } - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - void push_back(const basic_json& val) - { - // push_back only works for null objects or arrays - if (not(is_null() or is_array())) + if (is_an_object) { - JSON_THROW(type_error::create(308, "cannot use push_back() with " + type_name())); - } + // the initializer list is a list of pairs -> create object + m_type = value_t::object; + m_value = value_t::object; - // transform null object into an array - if (is_null()) + std::for_each(init.begin(), init.end(), [this](const detail::json_ref& element_ref) + { + auto element = element_ref.moved_or_copied(); + m_value.object->emplace( + std::move(*((*element.m_value.array)[0].m_value.string)), + std::move((*element.m_value.array)[1])); + }); + } + else { + // the initializer list describes an array -> create array m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); + m_value.array = create(init.begin(), init.end()); } - // add element to array - m_value.array->push_back(val); - } - - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - reference operator+=(const basic_json& val) - { - push_back(val); - return *this; + assert_invariant(); } /*! - @brief add an object to an object + @brief explicitly create an array from an initializer list - Inserts the given element @a val to the JSON object. If the function is - called on a JSON null value, an empty object is created before inserting - @a val. + Creates a JSON array value from a given initializer list. That is, given a + list of values `a, b, c`, creates the JSON value `[a, b, c]`. If the + initializer list is empty, the empty array `[]` is created. - @param[in] val the value to add to the JSON object + @note This function is only needed to express two edge cases that cannot + be realized with the initializer list constructor (@ref + basic_json(initializer_list_t, bool, value_t)). These cases + are: + 1. creating an array whose elements are all pairs whose first element is a + string -- in this case, the initializer list constructor would create an + object, taking the first elements as keys + 2. creating an empty array -- passing the empty initializer list to the + initializer list constructor yields an empty object - @throw type_error.308 when called on a type other than JSON object or - null; example: `"cannot use push_back() with number"` + @param[in] init initializer list with JSON values to create an array from + (optional) - @complexity Logarithmic in the size of the container, O(log(`size()`)). + @return JSON array value - @liveexample{The example shows how `push_back()` and `+=` can be used to - add elements to a JSON object. Note how the `null` value was silently - converted to a JSON object.,push_back__object_t__value} + @complexity Linear in the size of @a init. - @since version 1.0.0 - */ - void push_back(const typename object_t::value_type& val) - { - // push_back only works for null objects or objects - if (not(is_null() or is_object())) - { - JSON_THROW(type_error::create(308, "cannot use push_back() with " + type_name())); - } + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - // transform null object into an object - if (is_null()) - { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); - } + @liveexample{The following code shows an example for the `array` + function.,array} - // add element to array - m_value.object->insert(val); - } + @sa @ref basic_json(initializer_list_t, bool, value_t) -- + create a JSON value from an initializer list + @sa @ref object(initializer_list_t) -- create a JSON object + value from an initializer list - /*! - @brief add an object to an object - @copydoc push_back(const typename object_t::value_type&) + @since version 1.0.0 */ - reference operator+=(const typename object_t::value_type& val) + static basic_json array(initializer_list_t init = {}) { - push_back(val); - return *this; + return basic_json(init, false, value_t::array); } /*! - @brief add an object to an object + @brief explicitly create an object from an initializer list - This function allows to use `push_back` with an initializer list. In case + Creates a JSON object value from a given initializer list. The initializer + lists elements must be pairs, and their first elements must be strings. If + the initializer list is empty, the empty object `{}` is created. - 1. the current value is an object, - 2. the initializer list @a init contains only two elements, and - 3. the first element of @a init is a string, + @note This function is only added for symmetry reasons. In contrast to the + related function @ref array(initializer_list_t), there are + no cases which can only be expressed by this function. That is, any + initializer list @a init can also be passed to the initializer list + constructor @ref basic_json(initializer_list_t, bool, value_t). - @a init is converted into an object element and added using - @ref push_back(const typename object_t::value_type&). Otherwise, @a init - is converted to a JSON value and added using @ref push_back(basic_json&&). + @param[in] init initializer list to create an object from (optional) - @param[in] init an initializer list + @return JSON object value - @complexity Linear in the size of the initializer list @a init. + @throw type_error.301 if @a init is not a list of pairs whose first + elements are strings. In this case, no object can be created. When such a + value is passed to @ref basic_json(initializer_list_t, bool, value_t), + an array would have been created from the passed initializer list @a init. + See example below. - @note This function is required to resolve an ambiguous overload error, - because pairs like `{"key", "value"}` can be both interpreted as - `object_t::value_type` or `std::initializer_list`, see - https://github.com/nlohmann/json/issues/235 for more information. + @complexity Linear in the size of @a init. - @liveexample{The example shows how initializer lists are treated as - objects when possible.,push_back__initializer_list} + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. + + @liveexample{The following code shows an example for the `object` + function.,object} + + @sa @ref basic_json(initializer_list_t, bool, value_t) -- + create a JSON value from an initializer list + @sa @ref array(initializer_list_t) -- create a JSON array + value from an initializer list + + @since version 1.0.0 */ - void push_back(std::initializer_list init) + static basic_json object(initializer_list_t init = {}) { - if (is_object() and init.size() == 2 and init.begin()->is_string()) - { - const string_t key = *init.begin(); - push_back(typename object_t::value_type(key, *(init.begin() + 1))); - } - else - { - push_back(basic_json(init)); - } + return basic_json(init, false, value_t::object); } /*! - @brief add an object to an object - @copydoc push_back(std::initializer_list) + @brief construct an array with count copies of given value + + Constructs a JSON array value by creating @a cnt copies of a passed value. + In case @a cnt is `0`, an empty array is created. + + @param[in] cnt the number of JSON copies of @a val to create + @param[in] val the JSON value to copy + + @post `std::distance(begin(),end()) == cnt` holds. + + @complexity Linear in @a cnt. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. + + @liveexample{The following code shows examples for the @ref + basic_json(size_type\, const basic_json&) + constructor.,basic_json__size_type_basic_json} + + @since version 1.0.0 */ - reference operator+=(std::initializer_list init) + basic_json(size_type cnt, const basic_json& val) + : m_type(value_t::array) { - push_back(init); - return *this; + m_value.array = create(cnt, val); + assert_invariant(); } /*! - @brief add an object to an array + @brief construct a JSON container given an iterator range - Creates a JSON value from the passed parameters @a args to the end of the - JSON value. If the function is called on a JSON null value, an empty array - is created before appending the value created from @a args. + Constructs the JSON value with the contents of the range `[first, last)`. + The semantics depends on the different types a JSON value can have: + - In case of a null type, invalid_iterator.206 is thrown. + - In case of other primitive types (number, boolean, or string), @a first + must be `begin()` and @a last must be `end()`. In this case, the value is + copied. Otherwise, invalid_iterator.204 is thrown. + - In case of structured types (array, object), the constructor behaves as + similar versions for `std::vector` or `std::map`; that is, a JSON array + or object is constructed from the values in the range. - @param[in] args arguments to forward to a constructor of @ref basic_json - @tparam Args compatible types to create a @ref basic_json object + @tparam InputIT an input iterator type (@ref iterator or @ref + const_iterator) - @throw type_error.311 when called on a type other than JSON array or - null; example: `"cannot use emplace_back() with number"` + @param[in] first begin of the range to copy from (included) + @param[in] last end of the range to copy from (excluded) - @complexity Amortized constant. + @pre Iterators @a first and @a last must be initialized. **This + precondition is enforced with an assertion (see warning).** If + assertions are switched off, a violation of this precondition yields + undefined behavior. - @liveexample{The example shows how `push_back()` can be used to add - elements to a JSON array. Note how the `null` value was silently converted - to a JSON array.,emplace_back} + @pre Range `[first, last)` is valid. Usually, this precondition cannot be + checked efficiently. Only certain edge cases are detected; see the + description of the exceptions below. A violation of this precondition + yields undefined behavior. - @since version 2.0.8 + @warning A precondition is enforced with a runtime assertion that will + result in calling `std::abort` if this precondition is not met. + Assertions can be disabled by defining `NDEBUG` at compile time. + See http://en.cppreference.com/w/cpp/error/assert for more + information. + + @throw invalid_iterator.201 if iterators @a first and @a last are not + compatible (i.e., do not belong to the same JSON value). In this case, + the range `[first, last)` is undefined. + @throw invalid_iterator.204 if iterators @a first and @a last belong to a + primitive type (number, boolean, or string), but @a first does not point + to the first element any more. In this case, the range `[first, last)` is + undefined. See example code below. + @throw invalid_iterator.206 if iterators @a first and @a last belong to a + null value. In this case, the range `[first, last)` is undefined. + + @complexity Linear in distance between @a first and @a last. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. + + @liveexample{The example below shows several ways to create JSON values by + specifying a subrange with iterators.,basic_json__InputIt_InputIt} + + @since version 1.0.0 */ - template - void emplace_back(Args&& ... args) + template::value or + std::is_same::value, int>::type = 0> + basic_json(InputIT first, InputIT last) { - // emplace_back only works for null objects or arrays - if (not(is_null() or is_array())) + assert(first.m_object != nullptr); + assert(last.m_object != nullptr); + + // make sure iterator fits the current value + if (JSON_UNLIKELY(first.m_object != last.m_object)) { - JSON_THROW(type_error::create(311, "cannot use emplace_back() with " + type_name())); + JSON_THROW(invalid_iterator::create(201, "iterators are not compatible")); } - // transform null object into an array - if (is_null()) + // copy type from first iterator + m_type = first.m_object->m_type; + + // check if iterator range is complete for primitive values + switch (m_type) { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } + case value_t::boolean: + case value_t::number_float: + case value_t::number_integer: + case value_t::number_unsigned: + case value_t::string: + { + if (JSON_UNLIKELY(not first.m_it.primitive_iterator.is_begin() + or not last.m_it.primitive_iterator.is_end())) + { + JSON_THROW(invalid_iterator::create(204, "iterators out of range")); + } + break; + } - // add element to array (perfect forwarding) - m_value.array->emplace_back(std::forward(args)...); - } + default: + break; + } - /*! - @brief add an object to an object if key does not exist + switch (m_type) + { + case value_t::number_integer: + { + m_value.number_integer = first.m_object->m_value.number_integer; + break; + } - Inserts a new element into a JSON object constructed in-place with the - given @a args if there is no element with the key in the container. If the - function is called on a JSON null value, an empty object is created before - appending the value created from @a args. + case value_t::number_unsigned: + { + m_value.number_unsigned = first.m_object->m_value.number_unsigned; + break; + } - @param[in] args arguments to forward to a constructor of @ref basic_json - @tparam Args compatible types to create a @ref basic_json object + case value_t::number_float: + { + m_value.number_float = first.m_object->m_value.number_float; + break; + } - @return a pair consisting of an iterator to the inserted element, or the - already-existing element if no insertion happened, and a bool - denoting whether the insertion took place. + case value_t::boolean: + { + m_value.boolean = first.m_object->m_value.boolean; + break; + } - @throw type_error.311 when called on a type other than JSON object or - null; example: `"cannot use emplace() with number"` + case value_t::string: + { + m_value = *first.m_object->m_value.string; + break; + } - @complexity Logarithmic in the size of the container, O(log(`size()`)). + case value_t::object: + { + m_value.object = create(first.m_it.object_iterator, + last.m_it.object_iterator); + break; + } - @liveexample{The example shows how `emplace()` can be used to add elements - to a JSON object. Note how the `null` value was silently converted to a - JSON object. Further note how no value is added if there was already one - value stored with the same key.,emplace} + case value_t::array: + { + m_value.array = create(first.m_it.array_iterator, + last.m_it.array_iterator); + break; + } - @since version 2.0.8 - */ - template - std::pair emplace(Args&& ... args) - { - // emplace only works for null objects or arrays - if (not(is_null() or is_object())) - { - JSON_THROW(type_error::create(311, "cannot use emplace() with " + type_name())); + default: + JSON_THROW(invalid_iterator::create(206, "cannot construct with iterators from " + + std::string(first.m_object->type_name()))); } - // transform null object into an object - if (is_null()) - { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); - } + assert_invariant(); + } - // add element to array (perfect forwarding) - auto res = m_value.object->emplace(std::forward(args)...); - // create result iterator and set iterator to the result of emplace - auto it = begin(); - it.m_it.object_iterator = res.first; - // return pair of iterator and boolean - return {it, res.second}; - } + /////////////////////////////////////// + // other constructors and destructor // + /////////////////////////////////////// + + /// @private + basic_json(const detail::json_ref& ref) + : basic_json(ref.moved_or_copied()) + {} /*! - @brief inserts element + @brief copy constructor + + Creates a copy of a given JSON value. - Inserts element @a val before iterator @a pos. + @param[in] other the JSON value to copy - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] val element to insert - @return iterator pointing to the inserted @a val. + @post `*this == other` - @throw type_error.309 if called on JSON values other than arrays; - example: `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` + @complexity Linear in the size of @a other. - @complexity Constant plus linear in the distance between @a pos and end of - the container. + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @liveexample{The example shows how `insert()` is used.,insert} + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is linear. + - As postcondition, it holds: `other == basic_json(other)`. + + @liveexample{The following code shows an example for the copy + constructor.,basic_json__basic_json} @since version 1.0.0 */ - iterator insert(const_iterator pos, const basic_json& val) + basic_json(const basic_json& other) + : m_type(other.m_type) { - // insert only works for arrays - if (is_array()) + // check of passed value is valid + other.assert_invariant(); + + switch (m_type) { - // check if iterator pos fits to this JSON value - if (pos.m_object != this) + case value_t::object: { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + m_value = *other.m_value.object; + break; } - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, val); - return result; + case value_t::array: + { + m_value = *other.m_value.array; + break; + } + + case value_t::string: + { + m_value = *other.m_value.string; + break; + } + + case value_t::boolean: + { + m_value = other.m_value.boolean; + break; + } + + case value_t::number_integer: + { + m_value = other.m_value.number_integer; + break; + } + + case value_t::number_unsigned: + { + m_value = other.m_value.number_unsigned; + break; + } + + case value_t::number_float: + { + m_value = other.m_value.number_float; + break; + } + + default: + break; } - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); + assert_invariant(); } /*! - @brief inserts element - @copydoc insert(const_iterator, const basic_json&) - */ - iterator insert(const_iterator pos, basic_json&& val) - { - return insert(pos, val); - } + @brief move constructor - /*! - @brief inserts elements + Move constructor. Constructs a JSON value with the contents of the given + value @a other using move semantics. It "steals" the resources from @a + other and leaves it as JSON null value. - Inserts @a cnt copies of @a val before iterator @a pos. + @param[in,out] other value to move to this object - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] cnt number of copies of @a val to insert - @param[in] val element to insert - @return iterator pointing to the first element inserted, or @a pos if - `cnt==0` + @post `*this` has the same value as @a other before the call. + @post @a other is a JSON null value. - @throw type_error.309 if called on JSON values other than arrays; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` + @complexity Constant. - @complexity Linear in @a cnt plus linear in the distance between @a pos - and end of the container. + @exceptionsafety No-throw guarantee: this constructor never throws + exceptions. - @liveexample{The example shows how `insert()` is used.,insert__count} + @requirement This function helps `basic_json` satisfying the + [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible) + requirements. + + @liveexample{The code below shows the move constructor explicitly called + via std::move.,basic_json__moveconstructor} @since version 1.0.0 */ - iterator insert(const_iterator pos, size_type cnt, const basic_json& val) + basic_json(basic_json&& other) noexcept + : m_type(std::move(other.m_type)), + m_value(std::move(other.m_value)) { - // insert only works for arrays - if (is_array()) - { - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } + // check that passed value is valid + other.assert_invariant(); - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val); - return result; - } + // invalidate payload + other.m_type = value_t::null; + other.m_value = {}; - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); + assert_invariant(); } /*! - @brief inserts elements - - Inserts elements from range `[first, last)` before iterator @a pos. + @brief copy assignment - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] first begin of the range of elements to insert - @param[in] last end of the range of elements to insert + Copy assignment operator. Copies a JSON value via the "copy and swap" + strategy: It is expressed in terms of the copy constructor, destructor, + and the `swap()` member function. - @throw type_error.309 if called on JSON values other than arrays; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` - @throw invalid_iterator.210 if @a first and @a last do not belong to the - same JSON value; example: `"iterators do not fit"` - @throw invalid_iterator.211 if @a first or @a last are iterators into - container for which insert is called; example: `"passed iterators may not - belong to container"` + @param[in] other value to copy from - @return iterator pointing to the first element inserted, or @a pos if - `first==last` + @complexity Linear. - @complexity Linear in `std::distance(first, last)` plus linear in the - distance between @a pos and end of the container. + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is linear. - @liveexample{The example shows how `insert()` is used.,insert__range} + @liveexample{The code below shows and example for the copy assignment. It + creates a copy of value `a` which is then swapped with `b`. Finally\, the + copy of `a` (which is the null value after the swap) is + destroyed.,basic_json__copyassignment} @since version 1.0.0 */ - iterator insert(const_iterator pos, const_iterator first, const_iterator last) + reference& operator=(basic_json other) noexcept ( + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value and + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value + ) { - // insert only works for arrays - if (not is_array()) - { - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } - - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } - - // check if range iterators belong to the same JSON object - if (first.m_object != last.m_object) - { - JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); - } + // check that passed value is valid + other.assert_invariant(); - if (first.m_object == this or last.m_object == this) - { - JSON_THROW(invalid_iterator::create(211, "passed iterators may not belong to container")); - } + using std::swap; + swap(m_type, other.m_type); + swap(m_value, other.m_value); - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert( - pos.m_it.array_iterator, - first.m_it.array_iterator, - last.m_it.array_iterator); - return result; + assert_invariant(); + return *this; } /*! - @brief inserts elements - - Inserts elements from initializer list @a ilist before iterator @a pos. - - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] ilist initializer list to insert the values from - - @throw type_error.309 if called on JSON values other than arrays; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` + @brief destructor - @return iterator pointing to the first element inserted, or @a pos if - `ilist` is empty + Destroys the JSON value and frees all allocated memory. - @complexity Linear in `ilist.size()` plus linear in the distance between - @a pos and end of the container. + @complexity Linear. - @liveexample{The example shows how `insert()` is used.,insert__ilist} + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is linear. + - All stored elements are destroyed and all memory is freed. @since version 1.0.0 */ - iterator insert(const_iterator pos, std::initializer_list ilist) + ~basic_json() noexcept { - // insert only works for arrays - if (not is_array()) - { - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } + assert_invariant(); + m_value.destroy(m_type); + } - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } + /// @} + + public: + /////////////////////// + // object inspection // + /////////////////////// + + /// @name object inspection + /// Functions to inspect the type of a JSON value. + /// @{ + + /*! + @brief serialization + + Serialization function for JSON values. The function tries to mimic + Python's `json.dumps()` function, and currently supports its @a indent + and @a ensure_ascii parameters. - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist); - return result; - } + @param[in] indent If indent is nonnegative, then array elements and object + members will be pretty-printed with that indent level. An indent level of + `0` will only insert newlines. `-1` (the default) selects the most compact + representation. + @param[in] indent_char The character to use for indentation if @a indent is + greater than `0`. The default is ` ` (space). + @param[in] ensure_ascii If @a ensure_ascii is true, all non-ASCII characters + in the output are escaped with `\uXXXX` sequences, and the result consists + of ASCII characters only. - /*! - @brief inserts elements + @return string containing the serialization of the JSON value - Inserts elements from range `[first, last)`. + @throw type_error.316 if a string stored inside the JSON value is not + UTF-8 encoded - @param[in] first begin of the range of elements to insert - @param[in] last end of the range of elements to insert + @complexity Linear. - @throw type_error.309 if called on JSON values other than objects; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if iterator @a first or @a last does does not - point to an object; example: `"iterators first and last must point to - objects"` - @throw invalid_iterator.210 if @a first and @a last do not belong to the - same JSON value; example: `"iterators do not fit"` + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. - @complexity Logarithmic: `O(N*log(size() + N))`, where `N` is the number - of elements to insert. + @liveexample{The following example shows the effect of different @a indent\, + @a indent_char\, and @a ensure_ascii parameters to the result of the + serialization.,dump} - @liveexample{The example shows how `insert()` is used.,insert__range_object} + @see https://docs.python.org/2/library/json.html#json.dump - @since version 3.0.0 + @since version 1.0.0; indentation character @a indent_char, option + @a ensure_ascii and exceptions added in version 3.0.0 */ - void insert(const_iterator first, const_iterator last) + string_t dump(const int indent = -1, const char indent_char = ' ', + const bool ensure_ascii = false) const { - // insert only works for objects - if (not is_object()) - { - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } + string_t result; + serializer s(detail::output_adapter(result), indent_char); - // check if range iterators belong to the same JSON object - if (first.m_object != last.m_object) + if (indent >= 0) { - JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + s.dump(*this, true, ensure_ascii, static_cast(indent)); } - - // passed iterators must belong to objects - if (not first.m_object->is_object() or not first.m_object->is_object()) + else { - JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects")); + s.dump(*this, false, ensure_ascii, 0); } - m_value.object->insert(first.m_it.object_iterator, last.m_it.object_iterator); + return result; } /*! - @brief exchanges the values + @brief return the type of the JSON value (explicit) - Exchanges the contents of the JSON value with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + Return the type of the JSON value as a value from the @ref value_t + enumeration. - @param[in,out] other JSON value to exchange the contents with + @return the type of the JSON value + Value type | return value + ------------------------- | ------------------------- + null | value_t::null + boolean | value_t::boolean + string | value_t::string + number (integer) | value_t::number_integer + number (unsigned integer) | value_t::number_unsigned + number (floating-point) | value_t::number_float + object | value_t::object + array | value_t::array + discarded | value_t::discarded @complexity Constant. - @liveexample{The example below shows how JSON values can be swapped with - `swap()`.,swap__reference} + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `type()` for all JSON + types.,type} + + @sa @ref operator value_t() -- return the type of the JSON value (implicit) + @sa @ref type_name() -- return the type as string @since version 1.0.0 */ - void swap(reference other) noexcept ( - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value and - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value - ) + constexpr value_t type() const noexcept { - std::swap(m_type, other.m_type); - std::swap(m_value, other.m_value); - assert_invariant(); + return m_type; } /*! - @brief exchanges the values - - Exchanges the contents of a JSON array with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + @brief return whether type is primitive - @param[in,out] other array to exchange the contents with + This function returns true if and only if the JSON type is primitive + (string, number, boolean, or null). - @throw type_error.310 when JSON value is not an array; example: `"cannot - use swap() with string"` + @return `true` if type is primitive (string, number, boolean, or null), + `false` otherwise. @complexity Constant. - @liveexample{The example below shows how arrays can be swapped with - `swap()`.,swap__array_t} + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_primitive()` for all JSON + types.,is_primitive} + + @sa @ref is_structured() -- returns whether JSON value is structured + @sa @ref is_null() -- returns whether JSON value is `null` + @sa @ref is_string() -- returns whether JSON value is a string + @sa @ref is_boolean() -- returns whether JSON value is a boolean + @sa @ref is_number() -- returns whether JSON value is a number @since version 1.0.0 */ - void swap(array_t& other) + constexpr bool is_primitive() const noexcept { - // swap only works for arrays - if (is_array()) - { - std::swap(*(m_value.array), other); - } - else - { - JSON_THROW(type_error::create(310, "cannot use swap() with " + type_name())); - } + return is_null() or is_string() or is_boolean() or is_number(); } /*! - @brief exchanges the values - - Exchanges the contents of a JSON object with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + @brief return whether type is structured - @param[in,out] other object to exchange the contents with + This function returns true if and only if the JSON type is structured + (array or object). - @throw type_error.310 when JSON value is not an object; example: - `"cannot use swap() with string"` + @return `true` if type is structured (array or object), `false` otherwise. @complexity Constant. - @liveexample{The example below shows how objects can be swapped with - `swap()`.,swap__object_t} + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_structured()` for all JSON + types.,is_structured} + + @sa @ref is_primitive() -- returns whether value is primitive + @sa @ref is_array() -- returns whether value is an array + @sa @ref is_object() -- returns whether value is an object @since version 1.0.0 */ - void swap(object_t& other) + constexpr bool is_structured() const noexcept { - // swap only works for objects - if (is_object()) - { - std::swap(*(m_value.object), other); - } - else - { - JSON_THROW(type_error::create(310, "cannot use swap() with " + type_name())); - } + return is_array() or is_object(); } /*! - @brief exchanges the values - - Exchanges the contents of a JSON string with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + @brief return whether value is null - @param[in,out] other string to exchange the contents with + This function returns true if and only if the JSON value is null. - @throw type_error.310 when JSON value is not a string; example: `"cannot - use swap() with boolean"` + @return `true` if type is null, `false` otherwise. @complexity Constant. - @liveexample{The example below shows how strings can be swapped with - `swap()`.,swap__string_t} + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_null()` for all JSON + types.,is_null} @since version 1.0.0 */ - void swap(string_t& other) + constexpr bool is_null() const noexcept { - // swap only works for strings - if (is_string()) - { - std::swap(*(m_value.string), other); - } - else - { - JSON_THROW(type_error::create(310, "cannot use swap() with " + type_name())); - } + return (m_type == value_t::null); } - /// @} - - public: - ////////////////////////////////////////// - // lexicographical comparison operators // - ////////////////////////////////////////// - - /// @name lexicographical comparison operators - /// @{ - /*! - @brief comparison: equal - - Compares two JSON values for equality according to the following rules: - - Two JSON values are equal if (1) they are from the same type and (2) - their stored values are the same according to their respective - `operator==`. - - Integer and floating-point numbers are automatically converted before - comparison. Floating-point numbers are compared indirectly: two - floating-point numbers `f1` and `f2` are considered equal if neither - `f1 > f2` nor `f2 > f1` holds. Note than two NaN values are always - treated as unequal. - - Two JSON null values are equal. - - @note NaN values never compare equal to themselves or to other NaN values. - - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether the values @a lhs and @a rhs are equal - - @complexity Linear. + @brief return whether value is a boolean - @liveexample{The example demonstrates comparing several JSON - types.,operator__equal} + This function returns true if and only if the JSON value is a boolean. - @since version 1.0.0 - */ - friend bool operator==(const_reference lhs, const_reference rhs) noexcept - { - const auto lhs_type = lhs.type(); - const auto rhs_type = rhs.type(); + @return `true` if type is boolean, `false` otherwise. - if (lhs_type == rhs_type) - { - switch (lhs_type) - { - case value_t::array: - { - return *lhs.m_value.array == *rhs.m_value.array; - } - case value_t::object: - { - return *lhs.m_value.object == *rhs.m_value.object; - } - case value_t::null: - { - return true; - } - case value_t::string: - { - return *lhs.m_value.string == *rhs.m_value.string; - } - case value_t::boolean: - { - return lhs.m_value.boolean == rhs.m_value.boolean; - } - case value_t::number_integer: - { - return lhs.m_value.number_integer == rhs.m_value.number_integer; - } - case value_t::number_unsigned: - { - return lhs.m_value.number_unsigned == rhs.m_value.number_unsigned; - } - case value_t::number_float: - { - return lhs.m_value.number_float == rhs.m_value.number_float; - } - default: - { - return false; - } - } - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_integer) == rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) - { - return lhs.m_value.number_float == static_cast(rhs.m_value.number_integer); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_float == static_cast(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) - { - return static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_integer; - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_integer == static_cast(rhs.m_value.number_unsigned); - } + @complexity Constant. - return false; - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - /*! - @brief comparison: equal - @copydoc operator==(const_reference, const_reference) + @liveexample{The following code exemplifies `is_boolean()` for all JSON + types.,is_boolean} + + @since version 1.0.0 */ - template::value, int>::type = 0> - friend bool operator==(const_reference lhs, const ScalarType rhs) noexcept + constexpr bool is_boolean() const noexcept { - return (lhs == basic_json(rhs)); + return (m_type == value_t::boolean); } /*! - @brief comparison: equal - @copydoc operator==(const_reference, const_reference) + @brief return whether value is a number + + This function returns true if and only if the JSON value is a number. This + includes both integer (signed and unsigned) and floating-point values. + + @return `true` if type is number (regardless whether integer, unsigned + integer or floating-type), `false` otherwise. + + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_number()` for all JSON + types.,is_number} + + @sa @ref is_number_integer() -- check if value is an integer or unsigned + integer number + @sa @ref is_number_unsigned() -- check if value is an unsigned integer + number + @sa @ref is_number_float() -- check if value is a floating-point number + + @since version 1.0.0 */ - template::value, int>::type = 0> - friend bool operator==(const ScalarType lhs, const_reference rhs) noexcept + constexpr bool is_number() const noexcept { - return (basic_json(lhs) == rhs); + return is_number_integer() or is_number_float(); } /*! - @brief comparison: not equal + @brief return whether value is an integer number - Compares two JSON values for inequality by calculating `not (lhs == rhs)`. + This function returns true if and only if the JSON value is a signed or + unsigned integer number. This excludes floating-point values. - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether the values @a lhs and @a rhs are not equal + @return `true` if type is an integer or unsigned integer number, `false` + otherwise. - @complexity Linear. + @complexity Constant. - @liveexample{The example demonstrates comparing several JSON - types.,operator__notequal} + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_number_integer()` for all + JSON types.,is_number_integer} + + @sa @ref is_number() -- check if value is a number + @sa @ref is_number_unsigned() -- check if value is an unsigned integer + number + @sa @ref is_number_float() -- check if value is a floating-point number @since version 1.0.0 */ - friend bool operator!=(const_reference lhs, const_reference rhs) noexcept + constexpr bool is_number_integer() const noexcept { - return not (lhs == rhs); + return (m_type == value_t::number_integer or m_type == value_t::number_unsigned); } /*! - @brief comparison: not equal - @copydoc operator!=(const_reference, const_reference) + @brief return whether value is an unsigned integer number + + This function returns true if and only if the JSON value is an unsigned + integer number. This excludes floating-point and signed integer values. + + @return `true` if type is an unsigned integer number, `false` otherwise. + + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_number_unsigned()` for all + JSON types.,is_number_unsigned} + + @sa @ref is_number() -- check if value is a number + @sa @ref is_number_integer() -- check if value is an integer or unsigned + integer number + @sa @ref is_number_float() -- check if value is a floating-point number + + @since version 2.0.0 */ - template::value, int>::type = 0> - friend bool operator!=(const_reference lhs, const ScalarType rhs) noexcept + constexpr bool is_number_unsigned() const noexcept { - return (lhs != basic_json(rhs)); + return (m_type == value_t::number_unsigned); } /*! - @brief comparison: not equal - @copydoc operator!=(const_reference, const_reference) + @brief return whether value is a floating-point number + + This function returns true if and only if the JSON value is a + floating-point number. This excludes signed and unsigned integer values. + + @return `true` if type is a floating-point number, `false` otherwise. + + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_number_float()` for all + JSON types.,is_number_float} + + @sa @ref is_number() -- check if value is number + @sa @ref is_number_integer() -- check if value is an integer number + @sa @ref is_number_unsigned() -- check if value is an unsigned integer + number + + @since version 1.0.0 */ - template::value, int>::type = 0> - friend bool operator!=(const ScalarType lhs, const_reference rhs) noexcept + constexpr bool is_number_float() const noexcept { - return (basic_json(lhs) != rhs); + return (m_type == value_t::number_float); } /*! - @brief comparison: less than + @brief return whether value is an object - Compares whether one JSON value @a lhs is less than another JSON value @a - rhs according to the following rules: - - If @a lhs and @a rhs have the same type, the values are compared using - the default `<` operator. - - Integer and floating-point numbers are automatically converted before - comparison - - In case @a lhs and @a rhs have different types, the values are ignored - and the order of the types is considered, see - @ref operator<(const value_t, const value_t). + This function returns true if and only if the JSON value is an object. - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is less than @a rhs + @return `true` if type is object, `false` otherwise. - @complexity Linear. + @complexity Constant. - @liveexample{The example demonstrates comparing several JSON - types.,operator__less} + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_object()` for all JSON + types.,is_object} @since version 1.0.0 */ - friend bool operator<(const_reference lhs, const_reference rhs) noexcept + constexpr bool is_object() const noexcept { - const auto lhs_type = lhs.type(); - const auto rhs_type = rhs.type(); - - if (lhs_type == rhs_type) - { - switch (lhs_type) - { - case value_t::array: - { - //return *lhs.m_value.array < *rhs.m_value.array; - //return *lhs.m_value.array.operator<(rhs); - return (*lhs.m_value.array) < *rhs.m_value.array; - // return nlohmann::detail::operator<(lhs, rhs); - } - case value_t::object: - { - return *lhs.m_value.object < *rhs.m_value.object; - } - case value_t::null: - { - return false; - } - case value_t::string: - { - return *lhs.m_value.string < *rhs.m_value.string; - } - case value_t::boolean: - { - return lhs.m_value.boolean < rhs.m_value.boolean; - } - case value_t::number_integer: - { - return lhs.m_value.number_integer < rhs.m_value.number_integer; - } - case value_t::number_unsigned: - { - return lhs.m_value.number_unsigned < rhs.m_value.number_unsigned; - } - case value_t::number_float: - { - return lhs.m_value.number_float < rhs.m_value.number_float; - } - default: - { - return false; - } - } - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_integer) < rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) - { - return lhs.m_value.number_float < static_cast(rhs.m_value.number_integer); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_float < static_cast(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_integer < static_cast(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) - { - return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_integer; - } - - // We only reach this line if we cannot compare values. In that case, - // we compare types. Note we have to call the operator explicitly, - // because MSVC has problems otherwise. - return operator<(lhs_type, rhs_type); + return (m_type == value_t::object); } /*! - @brief comparison: less than - @copydoc operator<(const_reference, const_reference) + @brief return whether value is an array + + This function returns true if and only if the JSON value is an array. + + @return `true` if type is array, `false` otherwise. + + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_array()` for all JSON + types.,is_array} + + @since version 1.0.0 */ - template::value, int>::type = 0> - friend bool operator<(const_reference lhs, const ScalarType rhs) noexcept + constexpr bool is_array() const noexcept { - return (lhs < basic_json(rhs)); + return (m_type == value_t::array); } - /*! - @brief comparison: less than - @copydoc operator<(const_reference, const_reference) + /*! + @brief return whether value is a string + + This function returns true if and only if the JSON value is a string. + + @return `true` if type is string, `false` otherwise. + + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_string()` for all JSON + types.,is_string} + + @since version 1.0.0 */ - template::value, int>::type = 0> - friend bool operator<(const ScalarType lhs, const_reference rhs) noexcept + constexpr bool is_string() const noexcept { - return (basic_json(lhs) < rhs); + return (m_type == value_t::string); } /*! - @brief comparison: less than or equal + @brief return whether value is discarded - Compares whether one JSON value @a lhs is less than or equal to another - JSON value by calculating `not (rhs < lhs)`. + This function returns true if and only if the JSON value was discarded + during parsing with a callback function (see @ref parser_callback_t). - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is less than or equal to @a rhs + @note This function will always be `false` for JSON values after parsing. + That is, discarded values can only occur during parsing, but will be + removed when inside a structured value or replaced by null in other cases. - @complexity Linear. + @return `true` if type is discarded, `false` otherwise. - @liveexample{The example demonstrates comparing several JSON - types.,operator__greater} + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_discarded()` for all JSON + types.,is_discarded} @since version 1.0.0 */ - friend bool operator<=(const_reference lhs, const_reference rhs) noexcept + constexpr bool is_discarded() const noexcept { - return not (rhs < lhs); + return (m_type == value_t::discarded); } /*! - @brief comparison: less than or equal - @copydoc operator<=(const_reference, const_reference) + @brief return the type of the JSON value (implicit) + + Implicitly return the type of the JSON value as a value from the @ref + value_t enumeration. + + @return the type of the JSON value + + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies the @ref value_t operator for + all JSON types.,operator__value_t} + + @sa @ref type() -- return the type of the JSON value (explicit) + @sa @ref type_name() -- return the type as string + + @since version 1.0.0 */ - template::value, int>::type = 0> - friend bool operator<=(const_reference lhs, const ScalarType rhs) noexcept + constexpr operator value_t() const noexcept { - return (lhs <= basic_json(rhs)); + return m_type; } - /*! - @brief comparison: less than or equal - @copydoc operator<=(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator<=(const ScalarType lhs, const_reference rhs) noexcept + /// @} + + private: + ////////////////// + // value access // + ////////////////// + + /// get a boolean (explicit) + boolean_t get_impl(boolean_t* /*unused*/) const { - return (basic_json(lhs) <= rhs); - } + if (JSON_LIKELY(is_boolean())) + { + return m_value.boolean; + } - /*! - @brief comparison: greater than + JSON_THROW(type_error::create(302, "type must be boolean, but is " + std::string(type_name()))); + } - Compares whether one JSON value @a lhs is greater than another - JSON value by calculating `not (lhs <= rhs)`. + /// get a pointer to the value (object) + object_t* get_impl_ptr(object_t* /*unused*/) noexcept + { + return is_object() ? m_value.object : nullptr; + } - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is greater than to @a rhs + /// get a pointer to the value (object) + constexpr const object_t* get_impl_ptr(const object_t* /*unused*/) const noexcept + { + return is_object() ? m_value.object : nullptr; + } - @complexity Linear. + /// get a pointer to the value (array) + array_t* get_impl_ptr(array_t* /*unused*/) noexcept + { + return is_array() ? m_value.array : nullptr; + } - @liveexample{The example demonstrates comparing several JSON - types.,operator__lessequal} + /// get a pointer to the value (array) + constexpr const array_t* get_impl_ptr(const array_t* /*unused*/) const noexcept + { + return is_array() ? m_value.array : nullptr; + } - @since version 1.0.0 - */ - friend bool operator>(const_reference lhs, const_reference rhs) noexcept + /// get a pointer to the value (string) + string_t* get_impl_ptr(string_t* /*unused*/) noexcept { - return not (lhs <= rhs); + return is_string() ? m_value.string : nullptr; } - /*! - @brief comparison: greater than - @copydoc operator>(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator>(const_reference lhs, const ScalarType rhs) noexcept + /// get a pointer to the value (string) + constexpr const string_t* get_impl_ptr(const string_t* /*unused*/) const noexcept { - return (lhs > basic_json(rhs)); + return is_string() ? m_value.string : nullptr; } - /*! - @brief comparison: greater than - @copydoc operator>(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator>(const ScalarType lhs, const_reference rhs) noexcept + /// get a pointer to the value (boolean) + boolean_t* get_impl_ptr(boolean_t* /*unused*/) noexcept { - return (basic_json(lhs) > rhs); + return is_boolean() ? &m_value.boolean : nullptr; } - /*! - @brief comparison: greater than or equal + /// get a pointer to the value (boolean) + constexpr const boolean_t* get_impl_ptr(const boolean_t* /*unused*/) const noexcept + { + return is_boolean() ? &m_value.boolean : nullptr; + } - Compares whether one JSON value @a lhs is greater than or equal to another - JSON value by calculating `not (lhs < rhs)`. + /// get a pointer to the value (integer number) + number_integer_t* get_impl_ptr(number_integer_t* /*unused*/) noexcept + { + return is_number_integer() ? &m_value.number_integer : nullptr; + } - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is greater than or equal to @a rhs + /// get a pointer to the value (integer number) + constexpr const number_integer_t* get_impl_ptr(const number_integer_t* /*unused*/) const noexcept + { + return is_number_integer() ? &m_value.number_integer : nullptr; + } - @complexity Linear. + /// get a pointer to the value (unsigned number) + number_unsigned_t* get_impl_ptr(number_unsigned_t* /*unused*/) noexcept + { + return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + } - @liveexample{The example demonstrates comparing several JSON - types.,operator__greaterequal} + /// get a pointer to the value (unsigned number) + constexpr const number_unsigned_t* get_impl_ptr(const number_unsigned_t* /*unused*/) const noexcept + { + return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + } - @since version 1.0.0 - */ - friend bool operator>=(const_reference lhs, const_reference rhs) noexcept + /// get a pointer to the value (floating-point number) + number_float_t* get_impl_ptr(number_float_t* /*unused*/) noexcept { - return not (lhs < rhs); + return is_number_float() ? &m_value.number_float : nullptr; } - /*! - @brief comparison: greater than or equal - @copydoc operator>=(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator>=(const_reference lhs, const ScalarType rhs) noexcept + /// get a pointer to the value (floating-point number) + constexpr const number_float_t* get_impl_ptr(const number_float_t* /*unused*/) const noexcept { - return (lhs >= basic_json(rhs)); + return is_number_float() ? &m_value.number_float : nullptr; } /*! - @brief comparison: greater than or equal - @copydoc operator>=(const_reference, const_reference) + @brief helper function to implement get_ref() + + This function helps to implement get_ref() without code duplication for + const and non-const overloads + + @tparam ThisType will be deduced as `basic_json` or `const basic_json` + + @throw type_error.303 if ReferenceType does not match underlying value + type of the current JSON */ - template::value, int>::type = 0> - friend bool operator>=(const ScalarType lhs, const_reference rhs) noexcept + template + static ReferenceType get_ref_impl(ThisType& obj) { - return (basic_json(lhs) >= rhs); + // delegate the call to get_ptr<>() + auto ptr = obj.template get_ptr::type>(); + + if (JSON_LIKELY(ptr != nullptr)) + { + return *ptr; + } + + JSON_THROW(type_error::create(303, "incompatible ReferenceType for get_ref, actual type is " + std::string(obj.type_name()))); } - /// @} + public: + /// @name value access + /// Direct access to the stored value of a JSON value. + /// @{ - private: - ///////////////////// - // output adapters // - ///////////////////// + /*! + @brief get special-case overload - /// abstract output adapter interface - template - class output_adapter + This overloads avoids a lot of template boilerplate, it can be seen as the + identity method + + @tparam BasicJsonType == @ref basic_json + + @return a copy of *this + + @complexity Constant. + + @since version 2.1.0 + */ + template::type, basic_json_t>::value, + int> = 0> + basic_json get() const { - public: - virtual void write_character(CharType c) = 0; - virtual void write_characters(const CharType* s, size_t length) = 0; - virtual ~output_adapter() {} + return *this; + } - static std::shared_ptr> create(std::vector& vec) - { - return std::shared_ptr(new output_vector_adapter(vec)); - } + /*! + @brief get special-case overload - static std::shared_ptr> create(std::ostream& s) - { - return std::shared_ptr(new output_stream_adapter(s)); - } + This overloads converts the current @ref basic_json in a different + @ref basic_json type - static std::shared_ptr> create(std::string& s) - { - return std::shared_ptr(new output_string_adapter(s)); - } - }; + @tparam BasicJsonType == @ref basic_json - /// a type to simplify interfaces - template - using output_adapter_t = std::shared_ptr>; + @return a copy of *this, converted into @tparam BasicJsonType - /// output adapter for byte vectors - template - class output_vector_adapter : public output_adapter + @complexity Depending on the implementation of the called `from_json()` + method. + + @since version 3.1.2 + */ + template::value and + detail::is_basic_json::value, int> = 0> + BasicJsonType get() const { - public: - output_vector_adapter(std::vector& vec) - : v(vec) - {} + return *this; + } - void write_character(CharType c) override - { - v.push_back(c); - } + /*! + @brief get a value (explicit) - void write_characters(const CharType* s, size_t length) override - { - std::copy(s, s + length, std::back_inserter(v)); - } + Explicit type conversion between the JSON value and a compatible value + which is [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) + and [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). + The value is converted by calling the @ref json_serializer + `from_json()` method. - private: - std::vector& v; - }; + The function is equivalent to executing + @code {.cpp} + ValueType ret; + JSONSerializer::from_json(*this, ret); + return ret; + @endcode - /// putput adatpter for output streams - template - class output_stream_adapter : public output_adapter - { - public: - output_stream_adapter(std::basic_ostream& s) - : stream(s) - {} + This overloads is chosen if: + - @a ValueType is not @ref basic_json, + - @ref json_serializer has a `from_json()` method of the form + `void from_json(const basic_json&, ValueType&)`, and + - @ref json_serializer does not have a `from_json()` method of + the form `ValueType from_json(const basic_json&)` - void write_character(CharType c) override - { - stream.put(c); - } + @tparam ValueTypeCV the provided value type + @tparam ValueType the returned value type - void write_characters(const CharType* s, size_t length) override - { - stream.write(s, static_cast(length)); - } + @return copy of the JSON value, converted to @a ValueType - private: - std::basic_ostream& stream; - }; + @throw what @ref json_serializer `from_json()` method throws - /// output adapter for basic_string - template - class output_string_adapter : public output_adapter + @liveexample{The example below shows several conversions from JSON values + to other types. There a few things to note: (1) Floating-point numbers can + be converted to integers\, (2) A JSON array can be converted to a standard + `std::vector`\, (3) A JSON object can be converted to C++ + associative containers such as `std::unordered_map`.,get__ValueType_const} + + @since version 2.1.0 + */ + template, + detail::enable_if_t < + not detail::is_basic_json::value and + detail::has_from_json::value and + not detail::has_non_default_from_json::value, + int> = 0> + ValueType get() const noexcept(noexcept( + JSONSerializer::from_json(std::declval(), std::declval()))) { - public: - output_string_adapter(std::string& s) - : str(s) - {} + // we cannot static_assert on ValueTypeCV being non-const, because + // there is support for get(), which is why we + // still need the uncvref + static_assert(not std::is_reference::value, + "get() cannot be used with reference types, you might want to use get_ref()"); + static_assert(std::is_default_constructible::value, + "types must be DefaultConstructible when used with get()"); - void write_character(CharType c) override - { - str.push_back(c); - } + ValueType ret; + JSONSerializer::from_json(*this, ret); + return ret; + } - void write_characters(const CharType* s, size_t length) override - { - str.append(s, length); - } + /*! + @brief get a value (explicit); special case - private: - std::basic_string& str; - }; + Explicit type conversion between the JSON value and a compatible value + which is **not** [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) + and **not** [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). + The value is converted by calling the @ref json_serializer + `from_json()` method. + The function is equivalent to executing + @code {.cpp} + return JSONSerializer::from_json(*this); + @endcode - /////////////////// - // serialization // - /////////////////// + This overloads is chosen if: + - @a ValueType is not @ref basic_json and + - @ref json_serializer has a `from_json()` method of the form + `ValueType from_json(const basic_json&)` - /// @name serialization - /// @{ + @note If @ref json_serializer has both overloads of + `from_json()`, this one is chosen. - private: - /*! - @brief wrapper around the serialization functions - */ - class serializer - { - private: - serializer(const serializer&) = delete; - serializer& operator=(const serializer&) = delete; + @tparam ValueTypeCV the provided value type + @tparam ValueType the returned value type - public: - /*! - @param[in] s output stream to serialize to - @param[in] ichar indentation character to use - */ - serializer(output_adapter_t s, const char ichar) - : o(s), loc(std::localeconv()), - thousands_sep(!loc->thousands_sep ? '\0' : loc->thousands_sep[0]), - decimal_point(!loc->decimal_point ? '\0' : loc->decimal_point[0]), - indent_char(ichar), indent_string(512, indent_char) - {} + @return copy of the JSON value, converted to @a ValueType - /*! - @brief internal implementation of the serialization function + @throw what @ref json_serializer `from_json()` method throws - This function is called by the public member function dump and - organizes the serialization internally. The indentation level is - propagated as additional parameter. In case of arrays and objects, the - function is called recursively. + @since version 2.1.0 + */ + template, + detail::enable_if_t::value and + detail::has_non_default_from_json::value, + int> = 0> + ValueType get() const noexcept(noexcept( + JSONSerializer::from_json(std::declval()))) + { + static_assert(not std::is_reference::value, + "get() cannot be used with reference types, you might want to use get_ref()"); + return JSONSerializer::from_json(*this); + } - - strings and object keys are escaped using `escape_string()` - - integer numbers are converted implicitly via `operator<<` - - floating-point numbers are converted to a string using `"%g"` format + /*! + @brief get a pointer value (explicit) - @param[in] val value to serialize - @param[in] pretty_print whether the output shall be pretty-printed - @param[in] indent_step the indent level - @param[in] current_indent the current indent level (only used internally) - */ - void dump(const basic_json& val, - const bool pretty_print, - const unsigned int indent_step, - const unsigned int current_indent = 0) - { - switch (val.m_type) - { - case value_t::object: - { - if (val.m_value.object->empty()) - { - o->write_characters("{}", 2); - return; - } + Explicit pointer access to the internally stored JSON value. No copies are + made. - if (pretty_print) - { - o->write_characters("{\n", 2); + @warning The pointer becomes invalid if the underlying JSON object + changes. - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (indent_string.size() < new_indent) - { - indent_string.resize(new_indent, ' '); - } + @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref + object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, + @ref number_unsigned_t, or @ref number_float_t. - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\": ", 3); - dump(i->second, true, indent_step, new_indent); - o->write_characters(",\n", 2); - } + @return pointer to the internally stored JSON value if the requested + pointer type @a PointerType fits to the JSON value; `nullptr` otherwise - // last element - assert(i != val.m_value.object->cend()); - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\": ", 3); - dump(i->second, true, indent_step, new_indent); + @complexity Constant. - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character('}'); - } - else - { - o->write_character('{'); + @liveexample{The example below shows how pointers to internal values of a + JSON value can be requested. Note that no type conversions are made and a + `nullptr` is returned if the value and the requested pointer type does not + match.,get__PointerType} - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\":", 2); - dump(i->second, false, indent_step, current_indent); - o->write_character(','); - } + @sa @ref get_ptr() for explicit pointer-member access - // last element - assert(i != val.m_value.object->cend()); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\":", 2); - dump(i->second, false, indent_step, current_indent); + @since version 1.0.0 + */ + template::value, int>::type = 0> + PointerType get() noexcept + { + // delegate the call to get_ptr + return get_ptr(); + } - o->write_character('}'); - } + /*! + @brief get a pointer value (explicit) + @copydoc get() + */ + template::value, int>::type = 0> + constexpr const PointerType get() const noexcept + { + // delegate the call to get_ptr + return get_ptr(); + } - return; - } + /*! + @brief get a pointer value (implicit) - case value_t::array: - { - if (val.m_value.array->empty()) - { - o->write_characters("[]", 2); - return; - } + Implicit pointer access to the internally stored JSON value. No copies are + made. - if (pretty_print) - { - o->write_characters("[\n", 2); + @warning Writing data to the pointee of the result yields an undefined + state. - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (indent_string.size() < new_indent) - { - indent_string.resize(new_indent, ' '); - } + @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref + object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, + @ref number_unsigned_t, or @ref number_float_t. Enforced by a static + assertion. - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); i != val.m_value.array->cend() - 1; ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - dump(*i, true, indent_step, new_indent); - o->write_characters(",\n", 2); - } + @return pointer to the internally stored JSON value if the requested + pointer type @a PointerType fits to the JSON value; `nullptr` otherwise - // last element - assert(not val.m_value.array->empty()); - o->write_characters(indent_string.c_str(), new_indent); - dump(val.m_value.array->back(), true, indent_step, new_indent); + @complexity Constant. - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character(']'); - } - else - { - o->write_character('['); + @liveexample{The example below shows how pointers to internal values of a + JSON value can be requested. Note that no type conversions are made and a + `nullptr` is returned if the value and the requested pointer type does not + match.,get_ptr} - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); i != val.m_value.array->cend() - 1; ++i) - { - dump(*i, false, indent_step, current_indent); - o->write_character(','); - } + @since version 1.0.0 + */ + template::value, int>::type = 0> + PointerType get_ptr() noexcept + { + // get the type of the PointerType (remove pointer and const) + using pointee_t = typename std::remove_const::type>::type>::type; + // make sure the type matches the allowed types + static_assert( + std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + , "incompatible pointer type"); - // last element - assert(not val.m_value.array->empty()); - dump(val.m_value.array->back(), false, indent_step, current_indent); + // delegate the call to get_impl_ptr<>() + return get_impl_ptr(static_cast(nullptr)); + } - o->write_character(']'); - } + /*! + @brief get a pointer value (implicit) + @copydoc get_ptr() + */ + template::value and + std::is_const::type>::value, int>::type = 0> + constexpr const PointerType get_ptr() const noexcept + { + // get the type of the PointerType (remove pointer and const) + using pointee_t = typename std::remove_const::type>::type>::type; + // make sure the type matches the allowed types + static_assert( + std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + , "incompatible pointer type"); - return; - } + // delegate the call to get_impl_ptr<>() const + return get_impl_ptr(static_cast(nullptr)); + } - case value_t::string: - { - o->write_character('\"'); - dump_escaped(*val.m_value.string); - o->write_character('\"'); - return; - } + /*! + @brief get a reference value (implicit) - case value_t::boolean: - { - if (val.m_value.boolean) - { - o->write_characters("true", 4); - } - else - { - o->write_characters("false", 5); - } - return; - } + Implicit reference access to the internally stored JSON value. No copies + are made. - case value_t::number_integer: - { - dump_integer(val.m_value.number_integer); - return; - } + @warning Writing data to the referee of the result yields an undefined + state. - case value_t::number_unsigned: - { - dump_integer(val.m_value.number_unsigned); - return; - } + @tparam ReferenceType reference type; must be a reference to @ref array_t, + @ref object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or + @ref number_float_t. Enforced by static assertion. - case value_t::number_float: - { - dump_float(val.m_value.number_float); - return; - } + @return reference to the internally stored JSON value if the requested + reference type @a ReferenceType fits to the JSON value; throws + type_error.303 otherwise - case value_t::discarded: - { - o->write_characters("", 11); - return; - } + @throw type_error.303 in case passed type @a ReferenceType is incompatible + with the stored JSON value; see example below - case value_t::null: - { - o->write_characters("null", 4); - return; - } - } - } + @complexity Constant. - private: - /*! - @brief calculates the extra space to escape a JSON string + @liveexample{The example shows several calls to `get_ref()`.,get_ref} - @param[in] s the string to escape - @return the number of characters required to escape string @a s + @since version 1.1.0 + */ + template::value, int>::type = 0> + ReferenceType get_ref() + { + // delegate call to get_ref_impl + return get_ref_impl(*this); + } - @complexity Linear in the length of string @a s. - */ - static std::size_t extra_space(const string_t& s) noexcept - { - return std::accumulate(s.begin(), s.end(), size_t{}, - [](size_t res, typename string_t::value_type c) - { - switch (c) - { - case '"': - case '\\': - case '\b': - case '\f': - case '\n': - case '\r': - case '\t': - { - // from c (1 byte) to \x (2 bytes) - return res + 1; - } + /*! + @brief get a reference value (implicit) + @copydoc get_ref() + */ + template::value and + std::is_const::type>::value, int>::type = 0> + ReferenceType get_ref() const + { + // delegate call to get_ref_impl + return get_ref_impl(*this); + } - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x0b: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - // from c (1 byte) to \uxxxx (6 bytes) - return res + 5; - } + /*! + @brief get a value (implicit) - default: - { - return res; - } - } - }); - } + Implicit type conversion between the JSON value and a compatible value. + The call is realized by calling @ref get() const. - /*! - @brief dump escaped string + @tparam ValueType non-pointer type compatible to the JSON value, for + instance `int` for JSON integer numbers, `bool` for JSON booleans, or + `std::vector` types for JSON arrays. The character type of @ref string_t + as well as an initializer list of this type is excluded to avoid + ambiguities as these types implicitly convert to `std::string`. - Escape a string by replacing certain special characters by a sequence - of an escape character (backslash) and another character and other - control characters by a sequence of "\u" followed by a four-digit hex - representation. The escaped string is written to output stream @a o. + @return copy of the JSON value, converted to type @a ValueType - @param[in] s the string to escape + @throw type_error.302 in case passed type @a ValueType is incompatible + to the JSON value type (e.g., the JSON value is of type boolean, but a + string is requested); see example below - @complexity Linear in the length of string @a s. - */ - void dump_escaped(const string_t& s) const - { - const auto space = extra_space(s); - if (space == 0) - { - o->write_characters(s.c_str(), s.size()); - return; - } + @complexity Linear in the size of the JSON value. - // create a result string of necessary size - string_t result(s.size() + space, '\\'); - std::size_t pos = 0; + @liveexample{The example below shows several conversions from JSON values + to other types. There a few things to note: (1) Floating-point numbers can + be converted to integers\, (2) A JSON array can be converted to a standard + `std::vector`\, (3) A JSON object can be converted to C++ + associative containers such as `std::unordered_map`.,operator__ValueType} - for (const auto& c : s) - { - switch (c) - { - // quotation mark (0x22) - case '"': - { - result[pos + 1] = '"'; - pos += 2; - break; - } + @since version 1.0.0 + */ + template < typename ValueType, typename std::enable_if < + not std::is_pointer::value and + not std::is_same>::value and + not std::is_same::value and + not detail::is_basic_json::value +#ifndef _MSC_VER // fix for issue #167 operator<< ambiguity under VS2015 + and not std::is_same>::value +#endif +#if defined(JSON_HAS_CPP_17) + and not std::is_same::value +#endif + , int >::type = 0 > + operator ValueType() const + { + // delegate the call to get<>() const + return get(); + } - // reverse solidus (0x5c) - case '\\': - { - // nothing to change - pos += 2; - break; - } + /// @} - // backspace (0x08) - case '\b': - { - result[pos + 1] = 'b'; - pos += 2; - break; - } - // formfeed (0x0c) - case '\f': - { - result[pos + 1] = 'f'; - pos += 2; - break; - } + //////////////////// + // element access // + //////////////////// - // newline (0x0a) - case '\n': - { - result[pos + 1] = 'n'; - pos += 2; - break; - } + /// @name element access + /// Access to the JSON value. + /// @{ - // carriage return (0x0d) - case '\r': - { - result[pos + 1] = 'r'; - pos += 2; - break; - } + /*! + @brief access specified array element with bounds checking - // horizontal tab (0x09) - case '\t': - { - result[pos + 1] = 't'; - pos += 2; - break; - } + Returns a reference to the element at specified location @a idx, with + bounds checking. - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x0b: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - // convert a number 0..15 to its hex representation - // (0..f) - static const char hexify[16] = - { - '0', '1', '2', '3', '4', '5', '6', '7', - '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' - }; - - // print character c as \uxxxx - for (const char m : - { 'u', '0', '0', hexify[c >> 4], hexify[c & 0x0f] - }) - { - result[++pos] = m; - } + @param[in] idx index of the element to access - ++pos; - break; - } + @return reference to the element at index @a idx - default: - { - // all other characters are added as-is - result[pos++] = c; - break; - } - } - } + @throw type_error.304 if the JSON value is not an array; in this case, + calling `at` with an index makes no sense. See example below. + @throw out_of_range.401 if the index @a idx is out of range of the array; + that is, `idx >= size()`. See example below. - assert(pos == s.size() + space); - o->write_characters(result.c_str(), result.size()); - } + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. - /*! - @brief dump an integer + @complexity Constant. - Dump a given integer to output stream @a o. Works internally with - @a number_buffer. + @since version 1.0.0 - @param[in] x integer number (signed or unsigned) to dump - @tparam NumberType either @a number_integer_t or @a number_unsigned_t - */ - template::value or - std::is_same::value, int> = 0> - void dump_integer(NumberType x) + @liveexample{The example below shows how array elements can be read and + written using `at()`. It also demonstrates the different exceptions that + can be thrown.,at__size_type} + */ + reference at(size_type idx) + { + // at only works for arrays + if (JSON_LIKELY(is_array())) { - // special case for "0" - if (x == 0) - { - o->write_character('0'); - return; - } - - const bool is_negative = x < 0; - size_t i = 0; - - // spare 1 byte for '\0' - while (x != 0 and i < number_buffer.size() - 1) + JSON_TRY { - const auto digit = std::labs(static_cast(x % 10)); - number_buffer[i++] = static_cast('0' + digit); - x /= 10; + return m_value.array->at(idx); } - - // make sure the number has been processed completely - assert(x == 0); - - if (is_negative) + JSON_CATCH (std::out_of_range&) { - // make sure there is capacity for the '-' - assert(i < number_buffer.size() - 2); - number_buffer[i++] = '-'; + // create better exception explanation + JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); } - - std::reverse(number_buffer.begin(), number_buffer.begin() + i); - o->write_characters(number_buffer.data(), i); } - - /*! - @brief dump a floating-point number - - Dump a given floating-point number to output stream @a o. Works - internally with @a number_buffer. - - @param[in] x floating-point number to dump - */ - void dump_float(number_float_t x) + else { - // NaN / inf - if (not std::isfinite(x) or std::isnan(x)) - { - o->write_characters("null", 4); - return; - } + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } - // special case for 0.0 and -0.0 - if (x == 0) - { - if (std::signbit(x)) - { - o->write_characters("-0.0", 4); - } - else - { - o->write_characters("0.0", 3); - } - return; - } + /*! + @brief access specified array element with bounds checking - // get number of digits for a text -> float -> text round-trip - static constexpr auto d = std::numeric_limits::digits10; + Returns a const reference to the element at specified location @a idx, + with bounds checking. - // the actual conversion - std::ptrdiff_t len = snprintf(number_buffer.data(), number_buffer.size(), - "%.*g", d, x); + @param[in] idx index of the element to access - // negative value indicates an error - assert(len > 0); - // check if buffer was large enough - assert(static_cast(len) < number_buffer.size()); + @return const reference to the element at index @a idx - // erase thousands separator - if (thousands_sep != '\0') - { - const auto end = std::remove(number_buffer.begin(), - number_buffer.begin() + len, - thousands_sep); - std::fill(end, number_buffer.end(), '\0'); - assert((end - number_buffer.begin()) <= len); - len = (end - number_buffer.begin()); - } + @throw type_error.304 if the JSON value is not an array; in this case, + calling `at` with an index makes no sense. See example below. + @throw out_of_range.401 if the index @a idx is out of range of the array; + that is, `idx >= size()`. See example below. - // convert decimal point to '.' - if (decimal_point != '\0' and decimal_point != '.') - { - for (auto& c : number_buffer) - { - if (c == decimal_point) - { - c = '.'; - break; - } - } - } + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Constant. - o->write_characters(number_buffer.data(), static_cast(len)); + @since version 1.0.0 - // determine if need to append ".0" - const bool value_is_int_like = std::none_of(number_buffer.begin(), - number_buffer.begin() + len + 1, - [](char c) + @liveexample{The example below shows how array elements can be read using + `at()`. It also demonstrates the different exceptions that can be thrown., + at__size_type_const} + */ + const_reference at(size_type idx) const + { + // at only works for arrays + if (JSON_LIKELY(is_array())) + { + JSON_TRY { - return c == '.' or c == 'e'; - }); - - if (value_is_int_like) + return m_value.array->at(idx); + } + JSON_CATCH (std::out_of_range&) { - o->write_characters(".0", 2); + // create better exception explanation + JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); } } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } - private: - /// the output of the serializer - output_adapter_t o = nullptr; - - /// a (hopefully) large enough character buffer - std::array number_buffer{{}}; - - /// the locale - const std::lconv* loc = nullptr; - /// the locale's thousand separator character - const char thousands_sep = '\0'; - /// the locale's decimal point character - const char decimal_point = '\0'; - - /// the indentation character - const char indent_char; - - /// the indentation string - string_t indent_string; - }; - - public: /*! - @brief serialize to stream - - Serialize the given JSON value @a j to the output stream @a o. The JSON - value will be serialized using the @ref dump member function. - - - The indentation of the output can be controlled with the member variable - `width` of the output stream @a o. For instance, using the manipulator - `std::setw(4)` on @a o sets the indentation level to `4` and the - serialization result is the same as calling `dump(4)`. + @brief access specified object element with bounds checking - - The indentation characrer can be controlled with the member variable - `fill` of the output stream @a o. For instance, the manipulator - `std::setfill('\\t')` sets indentation to use a tab character rather than - the default space character. + Returns a reference to the element at with specified key @a key, with + bounds checking. - @param[in,out] o stream to serialize to - @param[in] j JSON value to serialize + @param[in] key key of the element to access - @return the stream @a o + @return reference to the element at key @a key - @complexity Linear. + @throw type_error.304 if the JSON value is not an object; in this case, + calling `at` with a key makes no sense. See example below. + @throw out_of_range.403 if the key @a key is is not stored in the object; + that is, `find(key) == end()`. See example below. - @liveexample{The example below shows the serialization with different - parameters to `width` to adjust the indentation level.,operator_serialize} + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. - @since version 1.0.0; indentaction character added in version 3.0.0 - */ - friend std::ostream& operator<<(std::ostream& o, const basic_json& j) - { - // read width member and use it as indentation parameter if nonzero - const bool pretty_print = (o.width() > 0); - const auto indentation = (pretty_print ? o.width() : 0); + @complexity Logarithmic in the size of the container. - // reset width to 0 for subsequent calls to this stream - o.width(0); + @sa @ref operator[](const typename object_t::key_type&) for unchecked + access by reference + @sa @ref value() for access by value with a default value - // do the actual serialization - serializer s(output_adapter::create(o), o.fill()); - s.dump(j, pretty_print, static_cast(indentation)); - return o; - } + @since version 1.0.0 - /*! - @brief serialize to stream - @deprecated This stream operator is deprecated and will be removed in a - future version of the library. Please use - @ref std::ostream& operator<<(std::ostream&, const basic_json&) - instead; that is, replace calls like `j >> o;` with `o << j;`. + @liveexample{The example below shows how object elements can be read and + written using `at()`. It also demonstrates the different exceptions that + can be thrown.,at__object_t_key_type} */ - JSON_DEPRECATED - friend std::ostream& operator>>(const basic_json& j, std::ostream& o) + reference at(const typename object_t::key_type& key) { - return o << j; + // at only works for objects + if (JSON_LIKELY(is_object())) + { + JSON_TRY + { + return m_value.object->at(key); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); + } + } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } } - /// @} - - - ///////////////////// - // deserialization // - ///////////////////// - - /// @name deserialization - /// @{ - /*! - @brief deserialize from an array + @brief access specified object element with bounds checking - This function reads from an array of 1-byte values. + Returns a const reference to the element at with specified key @a key, + with bounds checking. - @pre Each element of the container has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** + @param[in] key key of the element to access - @param[in] array array to read from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + @return const reference to the element at key @a key - @return result of the deserialization + @throw type_error.304 if the JSON value is not an object; in this case, + calling `at` with a key makes no sense. See example below. + @throw out_of_range.403 if the key @a key is is not stored in the object; + that is, `find(key) == end()`. See example below. - @throw parse_error.101 if a parse error occurs; example: `""unexpected end - of input; expected string literal""` - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + @complexity Logarithmic in the size of the container. - @note A UTF-8 byte order mark is silently ignored. + @sa @ref operator[](const typename object_t::key_type&) for unchecked + access by reference + @sa @ref value() for access by value with a default value - @liveexample{The example below demonstrates the `parse()` function reading - from an array.,parse__array__parser_callback_t} + @since version 1.0.0 - @since version 2.0.3 + @liveexample{The example below shows how object elements can be read using + `at()`. It also demonstrates the different exceptions that can be thrown., + at__object_t_key_type_const} */ - template - static basic_json parse(T (&array)[N], - const parser_callback_t cb = nullptr) + const_reference at(const typename object_t::key_type& key) const { - // delegate the call to the iterator-range parse overload - return parse(std::begin(array), std::end(array), cb); + // at only works for objects + if (JSON_LIKELY(is_object())) + { + JSON_TRY + { + return m_value.object->at(key); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); + } + } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } } /*! - @brief deserialize from string literal + @brief access specified array element - @tparam CharT character/literal type with size of 1 byte - @param[in] s string literal to read a serialized JSON value from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + Returns a reference to the element at specified location @a idx. - @return result of the deserialization + @note If @a idx is beyond the range of the array (i.e., `idx >= size()`), + then the array is silently filled up with `null` values to make `idx` a + valid reference to the last stored element. - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + @param[in] idx index of the element to access - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + @return reference to the element at index @a idx - @note A UTF-8 byte order mark is silently ignored. - @note String containers like `std::string` or @ref string_t can be parsed - with @ref parse(const ContiguousContainer&, const parser_callback_t) + @throw type_error.305 if the JSON value is not an array or null; in that + cases, using the [] operator with an index makes no sense. - @liveexample{The example below demonstrates the `parse()` function with - and without callback function.,parse__string__parser_callback_t} + @complexity Constant if @a idx is in the range of the array. Otherwise + linear in `idx - size()`. - @sa @ref parse(std::istream&, const parser_callback_t) for a version that - reads from an input stream + @liveexample{The example below shows how array elements can be read and + written using `[]` operator. Note the addition of `null` + values.,operatorarray__size_type} - @since version 1.0.0 (originally for @ref string_t) + @since version 1.0.0 */ - template::value and - std::is_integral::type>::value and - sizeof(typename std::remove_pointer::type) == 1, int>::type = 0> - static basic_json parse(const CharT s, - const parser_callback_t cb = nullptr) + reference operator[](size_type idx) { - return parser(input_adapter::create(s), cb).parse(true); + // implicitly convert null value to an empty array + if (is_null()) + { + m_type = value_t::array; + m_value.array = create(); + assert_invariant(); + } + + // operator[] only works for arrays + if (JSON_LIKELY(is_array())) + { + // fill up array with null values if given idx is outside range + if (idx >= m_value.array->size()) + { + m_value.array->insert(m_value.array->end(), + idx - m_value.array->size() + 1, + basic_json()); + } + + return m_value.array->operator[](idx); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); } /*! - @brief deserialize from stream - - @param[in,out] i stream to read a serialized JSON value from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + @brief access specified array element - @return result of the deserialization + Returns a const reference to the element at specified location @a idx. - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - @throw parse_error.111 if input stream is in a bad state + @param[in] idx index of the element to access - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + @return const reference to the element at index @a idx - @note A UTF-8 byte order mark is silently ignored. + @throw type_error.305 if the JSON value is not an array; in that case, + using the [] operator with an index makes no sense. - @liveexample{The example below demonstrates the `parse()` function with - and without callback function.,parse__istream__parser_callback_t} + @complexity Constant. - @sa @ref parse(const CharT, const parser_callback_t) for a version - that reads from a string + @liveexample{The example below shows how array elements can be read using + the `[]` operator.,operatorarray__size_type_const} @since version 1.0.0 */ - static basic_json parse(std::istream& i, - const parser_callback_t cb = nullptr) + const_reference operator[](size_type idx) const { - return parser(input_adapter::create(i), cb).parse(true); - } + // const operator[] only works for arrays + if (JSON_LIKELY(is_array())) + { + return m_value.array->operator[](idx); + } - /*! - @copydoc parse(std::istream&, const parser_callback_t) - */ - static basic_json parse(std::istream&& i, - const parser_callback_t cb = nullptr) - { - return parser(input_adapter::create(i), cb).parse(true); + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); } - /*! - @brief deserialize from an iterator range with contiguous storage - - This function reads from an iterator range of a container with contiguous - storage of 1-byte values. Compatible container types include - `std::vector`, `std::string`, `std::array`, `std::valarray`, and - `std::initializer_list`. Furthermore, C-style arrays can be used with - `std::begin()`/`std::end()`. User-defined containers can be used as long - as they implement random-access iterators and a contiguous storage. - - @pre The iterator range is contiguous. Violating this precondition yields - undefined behavior. **This precondition is enforced with an assertion.** - @pre Each element in the range has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** + /*! + @brief access specified object element - @warning There is no way to enforce all preconditions at compile-time. If - the function is called with noncompliant iterators and with - assertions switched off, the behavior is undefined and will most - likely yield segmentation violation. + Returns a reference to the element at with specified key @a key. - @tparam IteratorType iterator of container with contiguous storage - @param[in] first begin of the range to parse (included) - @param[in] last end of the range to parse (excluded) - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + @note If @a key is not found in the object, then it is silently added to + the object and filled with a `null` value to make `key` a valid reference. + In case the value was `null` before, it is converted to an object. - @return result of the deserialization + @param[in] key key of the element to access - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + @return reference to the element at key @a key - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + @throw type_error.305 if the JSON value is not an object or null; in that + cases, using the [] operator with a key makes no sense. - @note A UTF-8 byte order mark is silently ignored. + @complexity Logarithmic in the size of the container. - @liveexample{The example below demonstrates the `parse()` function reading - from an iterator range.,parse__iteratortype__parser_callback_t} + @liveexample{The example below shows how object elements can be read and + written using the `[]` operator.,operatorarray__key_type} - @since version 2.0.3 + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.0.0 */ - template::iterator_category>::value, int>::type = 0> - static basic_json parse(IteratorType first, IteratorType last, - const parser_callback_t cb = nullptr) + reference operator[](const typename object_t::key_type& key) { - return parser(input_adapter::create(first, last), cb).parse(true); + // implicitly convert null value to an empty object + if (is_null()) + { + m_type = value_t::object; + m_value.object = create(); + assert_invariant(); + } + + // operator[] only works for objects + if (JSON_LIKELY(is_object())) + { + return m_value.object->operator[](key); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); } /*! - @brief deserialize from a container with contiguous storage + @brief read-only access specified object element - This function reads from a container with contiguous storage of 1-byte - values. Compatible container types include `std::vector`, `std::string`, - `std::array`, and `std::initializer_list`. User-defined containers can be - used as long as they implement random-access iterators and a contiguous - storage. + Returns a const reference to the element at with specified key @a key. No + bounds checking is performed. - @pre The container storage is contiguous. Violating this precondition - yields undefined behavior. **This precondition is enforced with an - assertion.** - @pre Each element of the container has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** + @warning If the element with key @a key does not exist, the behavior is + undefined. - @warning There is no way to enforce all preconditions at compile-time. If - the function is called with a noncompliant container and with - assertions switched off, the behavior is undefined and will most - likely yield segmentation violation. + @param[in] key key of the element to access - @tparam ContiguousContainer container type with contiguous storage - @param[in] c container to read from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + @return const reference to the element at key @a key - @return result of the deserialization + @pre The element with key @a key must exist. **This precondition is + enforced with an assertion.** - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + @throw type_error.305 if the JSON value is not an object; in that case, + using the [] operator with a key makes no sense. - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + @complexity Logarithmic in the size of the container. - @note A UTF-8 byte order mark is silently ignored. + @liveexample{The example below shows how object elements can be read using + the `[]` operator.,operatorarray__key_type_const} - @liveexample{The example below demonstrates the `parse()` function reading - from a contiguous container.,parse__contiguouscontainer__parser_callback_t} + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value - @since version 2.0.3 + @since version 1.0.0 */ - template::value and - std::is_base_of< - std::random_access_iterator_tag, - typename std::iterator_traits()))>::iterator_category>::value - , int>::type = 0> - static basic_json parse(const ContiguousContainer& c, - const parser_callback_t cb = nullptr) + const_reference operator[](const typename object_t::key_type& key) const { - // delegate the call to the iterator-range parse overload - return parse(std::begin(c), std::end(c), cb); - } + // const operator[] only works for objects + if (JSON_LIKELY(is_object())) + { + assert(m_value.object->find(key) != m_value.object->end()); + return m_value.object->find(key)->second; + } - /*! - @brief deserialize from stream - @deprecated This stream operator is deprecated and will be removed in a - future version of the library. Please use - @ref std::istream& operator>>(std::istream&, basic_json&) - instead; that is, replace calls like `j << i;` with `i >> j;`. - */ - JSON_DEPRECATED - friend std::istream& operator<<(basic_json& j, std::istream& i) - { - j = parser(input_adapter::create(i)).parse(false); - return i; + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); } /*! - @brief deserialize from stream + @brief access specified object element - Deserializes an input stream to a JSON value. + Returns a reference to the element at with specified key @a key. - @param[in,out] i input stream to read a serialized JSON value from - @param[in,out] j JSON value to write the deserialized input to + @note If @a key is not found in the object, then it is silently added to + the object and filled with a `null` value to make `key` a valid reference. + In case the value was `null` before, it is converted to an object. - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - @throw parse_error.111 if input stream is in a bad state + @param[in] key key of the element to access - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. + @return reference to the element at key @a key - @note A UTF-8 byte order mark is silently ignored. + @throw type_error.305 if the JSON value is not an object or null; in that + cases, using the [] operator with a key makes no sense. - @liveexample{The example below shows how a JSON value is constructed by - reading a serialization from a stream.,operator_deserialize} + @complexity Logarithmic in the size of the container. - @sa parse(std::istream&, const parser_callback_t) for a variant with a - parser callback function to filter values while parsing + @liveexample{The example below shows how object elements can be read and + written using the `[]` operator.,operatorarray__key_type} - @since version 1.0.0 + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.1.0 */ - friend std::istream& operator>>(std::istream& i, basic_json& j) + template + reference operator[](T* key) { - j = parser(input_adapter::create(i)).parse(false); - return i; - } + // implicitly convert null to object + if (is_null()) + { + m_type = value_t::object; + m_value = value_t::object; + assert_invariant(); + } - /// @} + // at only works for objects + if (JSON_LIKELY(is_object())) + { + return m_value.object->operator[](key); + } - /////////////////////////// - // convenience functions // - /////////////////////////// + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } /*! - @brief return the type as string + @brief read-only access specified object element - Returns the type name as string to be used in error messages - usually to - indicate that a function was called on a wrong JSON type. + Returns a const reference to the element at with specified key @a key. No + bounds checking is performed. + + @warning If the element with key @a key does not exist, the behavior is + undefined. - @return basically a string representation of a the @a m_type member + @param[in] key key of the element to access - @complexity Constant. + @return const reference to the element at key @a key - @liveexample{The following code exemplifies `type_name()` for all JSON - types.,type_name} + @pre The element with key @a key must exist. **This precondition is + enforced with an assertion.** + + @throw type_error.305 if the JSON value is not an object; in that case, + using the [] operator with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be read using + the `[]` operator.,operatorarray__key_type_const} - @since version 1.0.0, public since 2.1.0 + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.1.0 */ - std::string type_name() const + template + const_reference operator[](T* key) const { + // at only works for objects + if (JSON_LIKELY(is_object())) { - switch (m_type) - { - case value_t::null: - return "null"; - case value_t::object: - return "object"; - case value_t::array: - return "array"; - case value_t::string: - return "string"; - case value_t::boolean: - return "boolean"; - case value_t::discarded: - return "discarded"; - default: - return "number"; - } + assert(m_value.object->find(key) != m_value.object->end()); + return m_value.object->find(key)->second; } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); } + /*! + @brief access specified object element with default value - private: - ////////////////////// - // member variables // - ////////////////////// + Returns either a copy of an object's element at the specified key @a key + or a given default value if no element with key @a key exists. - /// the type of the current element - value_t m_type = value_t::null; + The function is basically equivalent to executing + @code {.cpp} + try { + return at(key); + } catch(out_of_range) { + return default_value; + } + @endcode - /// the value of the current element - json_value m_value = {}; + @note Unlike @ref at(const typename object_t::key_type&), this function + does not throw if the given key @a key was not found. + @note Unlike @ref operator[](const typename object_t::key_type& key), this + function does not implicitly add an element to the position defined by @a + key. This function is furthermore also applicable to const objects. - private: - /////////////// - // iterators // - /////////////// + @param[in] key key of the element to access + @param[in] default_value the value to return if @a key is not found + + @tparam ValueType type compatible to JSON values, for instance `int` for + JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for + JSON arrays. Note the type of the expected value at @a key and the default + value @a default_value must be compatible. - /*! - @brief an iterator for primitive JSON types + @return copy of the element at key @a key or @a default_value if @a key + is not found - This class models an iterator for primitive JSON types (boolean, number, - string). It's only purpose is to allow the iterator/const_iterator classes - to "iterate" over primitive values. Internally, the iterator is modeled by - a `difference_type` variable. Value begin_value (`0`) models the begin, - end_value (`1`) models past the end. - */ - class primitive_iterator_t - { - public: + @throw type_error.306 if the JSON value is not an object; in that case, + using `value()` with a key makes no sense. - difference_type get_value() const noexcept - { - return m_it; - } - /// set iterator to a defined beginning - void set_begin() noexcept - { - m_it = begin_value; - } + @complexity Logarithmic in the size of the container. - /// set iterator to a defined past the end - void set_end() noexcept - { - m_it = end_value; - } + @liveexample{The example below shows how object elements can be queried + with a default value.,basic_json__value} - /// return whether the iterator can be dereferenced - constexpr bool is_begin() const noexcept - { - return (m_it == begin_value); - } + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref operator[](const typename object_t::key_type&) for unchecked + access by reference - /// return whether the iterator is at end - constexpr bool is_end() const noexcept + @since version 1.0.0 + */ + template::value, int>::type = 0> + ValueType value(const typename object_t::key_type& key, const ValueType& default_value) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) { - return (m_it == end_value); - } + // if key is found, return value and given default value otherwise + const auto it = find(key); + if (it != end()) + { + return *it; + } - friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it == rhs.m_it; + return default_value; } - friend constexpr bool operator!=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return !(lhs == rhs); - } + JSON_THROW(type_error::create(306, "cannot use value() with " + std::string(type_name()))); + } - friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it < rhs.m_it; - } + /*! + @brief overload for a default value of type const char* + @copydoc basic_json::value(const typename object_t::key_type&, ValueType) const + */ + string_t value(const typename object_t::key_type& key, const char* default_value) const + { + return value(key, string_t(default_value)); + } - friend constexpr bool operator<=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it <= rhs.m_it; - } + /*! + @brief access specified object element via JSON Pointer with default value - friend constexpr bool operator>(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it > rhs.m_it; - } + Returns either a copy of an object's element at the specified key @a key + or a given default value if no element with key @a key exists. - friend constexpr bool operator>=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it >= rhs.m_it; - } + The function is basically equivalent to executing + @code {.cpp} + try { + return at(ptr); + } catch(out_of_range) { + return default_value; + } + @endcode - primitive_iterator_t operator+(difference_type i) - { - auto result = *this; - result += i; - return result; - } + @note Unlike @ref at(const json_pointer&), this function does not throw + if the given key @a key was not found. - friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it - rhs.m_it; - } + @param[in] ptr a JSON pointer to the element to access + @param[in] default_value the value to return if @a ptr found no value - friend std::ostream& operator<<(std::ostream& os, primitive_iterator_t it) - { - return os << it.m_it; - } + @tparam ValueType type compatible to JSON values, for instance `int` for + JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for + JSON arrays. Note the type of the expected value at @a key and the default + value @a default_value must be compatible. - primitive_iterator_t& operator++() - { - ++m_it; - return *this; - } + @return copy of the element at key @a key or @a default_value if @a key + is not found - primitive_iterator_t operator++(int) - { - auto result = *this; - m_it++; - return result; - } + @throw type_error.306 if the JSON value is not an object; in that case, + using `value()` with a key makes no sense. - primitive_iterator_t& operator--() - { - --m_it; - return *this; - } + @complexity Logarithmic in the size of the container. - primitive_iterator_t operator--(int) - { - auto result = *this; - m_it--; - return result; - } + @liveexample{The example below shows how object elements can be queried + with a default value.,basic_json__value_ptr} - primitive_iterator_t& operator+=(difference_type n) - { - m_it += n; - return *this; - } + @sa @ref operator[](const json_pointer&) for unchecked access by reference - primitive_iterator_t& operator-=(difference_type n) + @since version 2.0.2 + */ + template::value, int>::type = 0> + ValueType value(const json_pointer& ptr, const ValueType& default_value) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) { - m_it -= n; - return *this; + // if pointer resolves a value, return it or use default value + JSON_TRY + { + return ptr.get_checked(this); + } + JSON_CATCH (out_of_range&) + { + return default_value; + } } - private: - static constexpr difference_type begin_value = 0; - static constexpr difference_type end_value = begin_value + 1; - - /// iterator as signed integer type - difference_type m_it = std::numeric_limits::denorm_min(); - }; + JSON_THROW(type_error::create(306, "cannot use value() with " + std::string(type_name()))); + } /*! - @brief an iterator value - - @note This structure could easily be a union, but MSVC currently does not - allow unions members with complex constructors, see - https://github.com/nlohmann/json/pull/105. + @brief overload for a default value of type const char* + @copydoc basic_json::value(const json_pointer&, ValueType) const */ - struct internal_iterator + string_t value(const json_pointer& ptr, const char* default_value) const { - /// iterator for JSON objects - typename object_t::iterator object_iterator; - /// iterator for JSON arrays - typename array_t::iterator array_iterator; - /// generic iterator for all other types - primitive_iterator_t primitive_iterator; - - /// create an uninitialized internal_iterator - internal_iterator() noexcept - : object_iterator(), array_iterator(), primitive_iterator() - {} - }; + return value(ptr, string_t(default_value)); + } - /// proxy class for the iterator_wrapper functions - template - class iteration_proxy - { - private: - /// helper class for iteration - class iteration_proxy_internal - { - private: - /// the iterator - IteratorType anchor; - /// an index for arrays (used to create key names) - size_t array_index = 0; + /*! + @brief access the first element - public: - explicit iteration_proxy_internal(IteratorType it) noexcept - : anchor(it) - {} + Returns a reference to the first element in the container. For a JSON + container `c`, the expression `c.front()` is equivalent to `*c.begin()`. - /// dereference operator (needed for range-based for) - iteration_proxy_internal& operator*() - { - return *this; - } + @return In case of a structured type (array or object), a reference to the + first element is returned. In case of number, string, or boolean values, a + reference to the value is returned. - /// increment operator (needed for range-based for) - iteration_proxy_internal& operator++() - { - ++anchor; - ++array_index; + @complexity Constant. - return *this; - } + @pre The JSON value must not be `null` (would throw `std::out_of_range`) + or an empty array or object (undefined behavior, **guarded by + assertions**). + @post The JSON value remains unchanged. - /// inequality operator (needed for range-based for) - bool operator!= (const iteration_proxy_internal& o) const - { - return anchor != o.anchor; - } + @throw invalid_iterator.214 when called on `null` value - /// return key of the iterator - typename basic_json::string_t key() const - { - assert(anchor.m_object != nullptr); + @liveexample{The following code shows an example for `front()`.,front} - switch (anchor.m_object->type()) - { - // use integer array index as key - case value_t::array: - { - return std::to_string(array_index); - } + @sa @ref back() -- access the last element - // use key from the object - case value_t::object: - { - return anchor.key(); - } + @since version 1.0.0 + */ + reference front() + { + return *begin(); + } - // use an empty key for all primitive types - default: - { - return ""; - } - } - } + /*! + @copydoc basic_json::front() + */ + const_reference front() const + { + return *cbegin(); + } - /// return value of the iterator - typename IteratorType::reference value() const - { - return anchor.value(); - } - }; + /*! + @brief access the last element - /// the container to iterate - typename IteratorType::reference container; + Returns a reference to the last element in the container. For a JSON + container `c`, the expression `c.back()` is equivalent to + @code {.cpp} + auto tmp = c.end(); + --tmp; + return *tmp; + @endcode - public: - /// construct iteration proxy from a container - explicit iteration_proxy(typename IteratorType::reference cont) - : container(cont) - {} + @return In case of a structured type (array or object), a reference to the + last element is returned. In case of number, string, or boolean values, a + reference to the value is returned. - /// return iterator begin (needed for range-based for) - iteration_proxy_internal begin() noexcept - { - return iteration_proxy_internal(container.begin()); - } + @complexity Constant. - /// return iterator end (needed for range-based for) - iteration_proxy_internal end() noexcept - { - return iteration_proxy_internal(container.end()); - } - }; + @pre The JSON value must not be `null` (would throw `std::out_of_range`) + or an empty array or object (undefined behavior, **guarded by + assertions**). + @post The JSON value remains unchanged. - public: - /*! - @brief a template for a random access iterator for the @ref basic_json class + @throw invalid_iterator.214 when called on a `null` value. See example + below. - This class implements a both iterators (iterator and const_iterator) for the - @ref basic_json class. + @liveexample{The following code shows an example for `back()`.,back} - @note An iterator is called *initialized* when a pointer to a JSON value - has been set (e.g., by a constructor or a copy assignment). If the - iterator is default-constructed, it is *uninitialized* and most - methods are undefined. **The library uses assertions to detect calls - on uninitialized iterators.** + @sa @ref front() -- access the first element - @requirement The class satisfies the following concept requirements: - - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator): - The iterator that can be moved to point (forward and backward) to any - element in constant time. + @since version 1.0.0 + */ + reference back() + { + auto tmp = end(); + --tmp; + return *tmp; + } - @since version 1.0.0, simplified in version 2.0.9 + /*! + @copydoc basic_json::back() */ - template - class iter_impl : public std::iterator + const_reference back() const { - /// allow basic_json to access private members - friend class basic_json; + auto tmp = cend(); + --tmp; + return *tmp; + } - // make sure U is basic_json or const basic_json - static_assert(std::is_same::value - or std::is_same::value, - "iter_impl only accepts (const) basic_json"); + /*! + @brief remove element given an iterator - public: - /// the type of the values when the iterator is dereferenced - using value_type = typename basic_json::value_type; - /// a type to represent differences between iterators - using difference_type = typename basic_json::difference_type; - /// defines a pointer to the type iterated over (value_type) - using pointer = typename std::conditional::value, - typename basic_json::const_pointer, - typename basic_json::pointer>::type; - /// defines a reference to the type iterated over (value_type) - using reference = typename std::conditional::value, - typename basic_json::const_reference, - typename basic_json::reference>::type; - /// the category of the iterator - using iterator_category = std::bidirectional_iterator_tag; - - /// default constructor - iter_impl() = default; - - /*! - @brief constructor for a given JSON instance - @param[in] object pointer to a JSON object for this iterator - @pre object != nullptr - @post The iterator is initialized; i.e. `m_object != nullptr`. - */ - explicit iter_impl(pointer object) noexcept - : m_object(object) - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = typename object_t::iterator(); - break; - } + Removes the element specified by iterator @a pos. The iterator @a pos must + be valid and dereferenceable. Thus the `end()` iterator (which is valid, + but is not dereferenceable) cannot be used as a value for @a pos. - case basic_json::value_t::array: - { - m_it.array_iterator = typename array_t::iterator(); - break; - } + If called on a primitive type other than `null`, the resulting JSON value + will be `null`. - default: - { - m_it.primitive_iterator = primitive_iterator_t(); - break; - } - } - } + @param[in] pos iterator to the element to remove + @return Iterator following the last removed element. If the iterator @a + pos refers to the last element, the `end()` iterator is returned. + + @tparam IteratorType an @ref iterator or @ref const_iterator - /* - Use operator `const_iterator` instead of `const_iterator(const iterator& - other) noexcept` to avoid two class definitions for @ref iterator and - @ref const_iterator. + @post Invalidates iterators and references at or after the point of the + erase, including the `end()` iterator. - This function is only called if this class is an @ref iterator. If this - class is a @ref const_iterator this function is not called. - */ - operator const_iterator() const - { - const_iterator ret; + @throw type_error.307 if called on a `null` value; example: `"cannot use + erase() with null"` + @throw invalid_iterator.202 if called on an iterator which does not belong + to the current JSON value; example: `"iterator does not fit current + value"` + @throw invalid_iterator.205 if called on a primitive type with invalid + iterator (i.e., any iterator which is not `begin()`); example: `"iterator + out of range"` - if (m_object) - { - ret.m_object = m_object; - ret.m_it = m_it; - } + @complexity The complexity depends on the type: + - objects: amortized constant + - arrays: linear in distance between @a pos and the end of the container + - strings: linear in the length of the string + - other types: constant - return ret; - } + @liveexample{The example shows the result of `erase()` for different JSON + types.,erase__IteratorType} - /*! - @brief copy constructor - @param[in] other iterator to copy from - @note It is not checked whether @a other is initialized. - */ - iter_impl(const iter_impl& other) noexcept - : m_object(other.m_object), m_it(other.m_it) - {} + @sa @ref erase(IteratorType, IteratorType) -- removes the elements in + the given range + @sa @ref erase(const typename object_t::key_type&) -- removes the element + from an object at the given key + @sa @ref erase(const size_type) -- removes the element from an array at + the given index - /*! - @brief copy assignment - @param[in,out] other iterator to copy from - @note It is not checked whether @a other is initialized. - */ - iter_impl& operator=(iter_impl other) noexcept( - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value and - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value - ) - { - std::swap(m_object, other.m_object); - std::swap(m_it, other.m_it); - return *this; + @since version 1.0.0 + */ + template::value or + std::is_same::value, int>::type + = 0> + IteratorType erase(IteratorType pos) + { + // make sure iterator fits the current value + if (JSON_UNLIKELY(this != pos.m_object)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); } - private: - /*! - @brief set the iterator to the first value - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - void set_begin() noexcept - { - assert(m_object != nullptr); + IteratorType result = end(); - switch (m_object->m_type) + switch (m_type) + { + case value_t::boolean: + case value_t::number_float: + case value_t::number_integer: + case value_t::number_unsigned: + case value_t::string: { - case basic_json::value_t::object: - { - m_it.object_iterator = m_object->m_value.object->begin(); - break; - } - - case basic_json::value_t::array: + if (JSON_UNLIKELY(not pos.m_it.primitive_iterator.is_begin())) { - m_it.array_iterator = m_object->m_value.array->begin(); - break; + JSON_THROW(invalid_iterator::create(205, "iterator out of range")); } - case basic_json::value_t::null: + if (is_string()) { - // set to end so begin()==end() is true: null is empty - m_it.primitive_iterator.set_end(); - break; + AllocatorType alloc; + std::allocator_traits::destroy(alloc, m_value.string); + std::allocator_traits::deallocate(alloc, m_value.string, 1); + m_value.string = nullptr; } - default: - { - m_it.primitive_iterator.set_begin(); - break; - } + m_type = value_t::null; + assert_invariant(); + break; } - } - /*! - @brief set the iterator past the last value - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - void set_end() noexcept - { - assert(m_object != nullptr); - - switch (m_object->m_type) + case value_t::object: { - case basic_json::value_t::object: - { - m_it.object_iterator = m_object->m_value.object->end(); - break; - } - - case basic_json::value_t::array: - { - m_it.array_iterator = m_object->m_value.array->end(); - break; - } + result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator); + break; + } - default: - { - m_it.primitive_iterator.set_end(); - break; - } + case value_t::array: + { + result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator); + break; } + + default: + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); } - public: - /*! - @brief return a reference to the value pointed to by the iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference operator*() const - { - assert(m_object != nullptr); + return result; + } - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - assert(m_it.object_iterator != m_object->m_value.object->end()); - return m_it.object_iterator->second; - } + /*! + @brief remove elements given an iterator range - case basic_json::value_t::array: - { - assert(m_it.array_iterator != m_object->m_value.array->end()); - return *m_it.array_iterator; - } + Removes the element specified by the range `[first; last)`. The iterator + @a first does not need to be dereferenceable if `first == last`: erasing + an empty range is a no-op. - case basic_json::value_t::null: - { - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } + If called on a primitive type other than `null`, the resulting JSON value + will be `null`. - default: - { - if (m_it.primitive_iterator.is_begin()) - { - return *m_object; - } + @param[in] first iterator to the beginning of the range to remove + @param[in] last iterator past the end of the range to remove + @return Iterator following the last removed element. If the iterator @a + second refers to the last element, the `end()` iterator is returned. - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } - } - } + @tparam IteratorType an @ref iterator or @ref const_iterator - /*! - @brief dereference the iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - pointer operator->() const - { - assert(m_object != nullptr); + @post Invalidates iterators and references at or after the point of the + erase, including the `end()` iterator. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - assert(m_it.object_iterator != m_object->m_value.object->end()); - return &(m_it.object_iterator->second); - } + @throw type_error.307 if called on a `null` value; example: `"cannot use + erase() with null"` + @throw invalid_iterator.203 if called on iterators which does not belong + to the current JSON value; example: `"iterators do not fit current value"` + @throw invalid_iterator.204 if called on a primitive type with invalid + iterators (i.e., if `first != begin()` and `last != end()`); example: + `"iterators out of range"` - case basic_json::value_t::array: - { - assert(m_it.array_iterator != m_object->m_value.array->end()); - return &*m_it.array_iterator; - } + @complexity The complexity depends on the type: + - objects: `log(size()) + std::distance(first, last)` + - arrays: linear in the distance between @a first and @a last, plus linear + in the distance between @a last and end of the container + - strings: linear in the length of the string + - other types: constant - default: - { - if (m_it.primitive_iterator.is_begin()) - { - return m_object; - } + @liveexample{The example shows the result of `erase()` for different JSON + types.,erase__IteratorType_IteratorType} - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } - } - } + @sa @ref erase(IteratorType) -- removes the element at a given position + @sa @ref erase(const typename object_t::key_type&) -- removes the element + from an object at the given key + @sa @ref erase(const size_type) -- removes the element from an array at + the given index - /*! - @brief post-increment (it++) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator++(int) + @since version 1.0.0 + */ + template::value or + std::is_same::value, int>::type + = 0> + IteratorType erase(IteratorType first, IteratorType last) + { + // make sure iterator fits the current value + if (JSON_UNLIKELY(this != first.m_object or this != last.m_object)) { - auto result = *this; - ++(*this); - return result; + JSON_THROW(invalid_iterator::create(203, "iterators do not fit current value")); } - /*! - @brief pre-increment (++it) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator++() - { - assert(m_object != nullptr); + IteratorType result = end(); - switch (m_object->m_type) + switch (m_type) + { + case value_t::boolean: + case value_t::number_float: + case value_t::number_integer: + case value_t::number_unsigned: + case value_t::string: { - case basic_json::value_t::object: + if (JSON_LIKELY(not first.m_it.primitive_iterator.is_begin() + or not last.m_it.primitive_iterator.is_end())) { - std::advance(m_it.object_iterator, 1); - break; + JSON_THROW(invalid_iterator::create(204, "iterators out of range")); } - case basic_json::value_t::array: + if (is_string()) { - std::advance(m_it.array_iterator, 1); - break; + AllocatorType alloc; + std::allocator_traits::destroy(alloc, m_value.string); + std::allocator_traits::deallocate(alloc, m_value.string, 1); + m_value.string = nullptr; } - default: - { - ++m_it.primitive_iterator; - break; - } + m_type = value_t::null; + assert_invariant(); + break; } - return *this; - } + case value_t::object: + { + result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator, + last.m_it.object_iterator); + break; + } - /*! - @brief post-decrement (it--) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator--(int) - { - auto result = *this; - --(*this); - return result; + case value_t::array: + { + result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator, + last.m_it.array_iterator); + break; + } + + default: + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); } - /*! - @brief pre-decrement (--it) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator--() - { - assert(m_object != nullptr); + return result; + } - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - std::advance(m_it.object_iterator, -1); - break; - } + /*! + @brief remove element from a JSON object given a key - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, -1); - break; - } + Removes elements from a JSON object with the key value @a key. - default: - { - --m_it.primitive_iterator; - break; - } - } + @param[in] key value of the elements to remove - return *this; - } + @return Number of elements removed. If @a ObjectType is the default + `std::map` type, the return value will always be `0` (@a key was not + found) or `1` (@a key was found). - /*! - @brief comparison: equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator==(const iter_impl& other) const - { - // if objects are not the same, the comparison is undefined - if (m_object != other.m_object) - { - JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); - } + @post References and iterators to the erased elements are invalidated. + Other references and iterators are not affected. - assert(m_object != nullptr); + @throw type_error.307 when called on a type other than JSON object; + example: `"cannot use erase() with null"` - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - return (m_it.object_iterator == other.m_it.object_iterator); - } + @complexity `log(size()) + count(key)` - case basic_json::value_t::array: - { - return (m_it.array_iterator == other.m_it.array_iterator); - } + @liveexample{The example shows the effect of `erase()`.,erase__key_type} - default: - { - return (m_it.primitive_iterator == other.m_it.primitive_iterator); - } - } - } + @sa @ref erase(IteratorType) -- removes the element at a given position + @sa @ref erase(IteratorType, IteratorType) -- removes the elements in + the given range + @sa @ref erase(const size_type) -- removes the element from an array at + the given index - /*! - @brief comparison: not equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator!=(const iter_impl& other) const + @since version 1.0.0 + */ + size_type erase(const typename object_t::key_type& key) + { + // this erase only works for objects + if (JSON_LIKELY(is_object())) { - return not operator==(other); + return m_value.object->erase(key); } - /*! - @brief comparison: smaller - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator<(const iter_impl& other) const - { - // if objects are not the same, the comparison is undefined - if (m_object != other.m_object) - { - JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); - } + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); + } - assert(m_object != nullptr); + /*! + @brief remove element from a JSON array given an index - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(213, "cannot compare order of object iterators")); - } + Removes element from a JSON array at the index @a idx. - case basic_json::value_t::array: - { - return (m_it.array_iterator < other.m_it.array_iterator); - } + @param[in] idx index of the element to remove - default: - { - return (m_it.primitive_iterator < other.m_it.primitive_iterator); - } - } - } + @throw type_error.307 when called on a type other than JSON object; + example: `"cannot use erase() with null"` + @throw out_of_range.401 when `idx >= size()`; example: `"array index 17 + is out of range"` - /*! - @brief comparison: less than or equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator<=(const iter_impl& other) const - { - return not other.operator < (*this); - } + @complexity Linear in distance between @a idx and the end of the container. - /*! - @brief comparison: greater than - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator>(const iter_impl& other) const - { - return not operator<=(other); - } + @liveexample{The example shows the effect of `erase()`.,erase__size_type} - /*! - @brief comparison: greater than or equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator>=(const iter_impl& other) const - { - return not operator<(other); - } + @sa @ref erase(IteratorType) -- removes the element at a given position + @sa @ref erase(IteratorType, IteratorType) -- removes the elements in + the given range + @sa @ref erase(const typename object_t::key_type&) -- removes the element + from an object at the given key - /*! - @brief add to iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator+=(difference_type i) + @since version 1.0.0 + */ + void erase(const size_type idx) + { + // this erase only works for arrays + if (JSON_LIKELY(is_array())) { - assert(m_object != nullptr); - - switch (m_object->m_type) + if (JSON_UNLIKELY(idx >= size())) { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); - } - - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, i); - break; - } - - default: - { - m_it.primitive_iterator += i; - break; - } + JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); } - return *this; + m_value.array->erase(m_value.array->begin() + static_cast(idx)); } - - /*! - @brief subtract from iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator-=(difference_type i) + else { - return operator+=(-i); + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); } + } - /*! - @brief add to iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator+(difference_type i) - { - auto result = *this; - result += i; - return result; - } + /// @} - /*! - @brief subtract from iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator-(difference_type i) - { - auto result = *this; - result -= i; - return result; - } - /*! - @brief return difference - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - difference_type operator-(const iter_impl& other) const - { - assert(m_object != nullptr); + //////////// + // lookup // + //////////// - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); - } + /// @name lookup + /// @{ - case basic_json::value_t::array: - { - return m_it.array_iterator - other.m_it.array_iterator; - } + /*! + @brief find an element in a JSON object - default: - { - return m_it.primitive_iterator - other.m_it.primitive_iterator; - } - } - } + Finds an element in a JSON object with key equivalent to @a key. If the + element is not found or the JSON value is not an object, end() is + returned. - /*! - @brief access to successor - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference operator[](difference_type n) const - { - assert(m_object != nullptr); + @note This method always returns @ref end() when executed on a JSON type + that is not an object. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(208, "cannot use operator[] for object iterators")); - } + @param[in] key key value of the element to search for. - case basic_json::value_t::array: - { - return *std::next(m_it.array_iterator, n); - } + @return Iterator to an element with key equivalent to @a key. If no such + element is found or the JSON value is not an object, past-the-end (see + @ref end()) iterator is returned. - case basic_json::value_t::null: - { - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } + @complexity Logarithmic in the size of the JSON object. - default: - { - if (m_it.primitive_iterator.get_value() == -n) - { - return *m_object; - } + @liveexample{The example shows how `find()` is used.,find__key_type} - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } - } - } + @since version 1.0.0 + */ + template + iterator find(KeyT&& key) + { + auto result = end(); - /*! - @brief return the key of an object iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - typename object_t::key_type key() const + if (is_object()) { - assert(m_object != nullptr); + result.m_it.object_iterator = m_value.object->find(std::forward(key)); + } - if (m_object->is_object()) - { - return m_it.object_iterator->first; - } + return result; + } - JSON_THROW(invalid_iterator::create(207, "cannot use key() for non-object iterators")); - } + /*! + @brief find an element in a JSON object + @copydoc find(KeyT&&) + */ + template + const_iterator find(KeyT&& key) const + { + auto result = cend(); - /*! - @brief return the value of an iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference value() const + if (is_object()) { - return operator*(); + result.m_it.object_iterator = m_value.object->find(std::forward(key)); } - private: - /// associated JSON instance - pointer m_object = nullptr; - /// the actual iterator of the associated instance - internal_iterator m_it = internal_iterator(); - }; + return result; + } /*! - @brief a template for a reverse iterator class + @brief returns the number of occurrences of a key in a JSON object + + Returns the number of elements with key @a key. If ObjectType is the + default `std::map` type, the return value will always be `0` (@a key was + not found) or `1` (@a key was found). + + @note This method always returns `0` when executed on a JSON type that is + not an object. + + @param[in] key key value of the element to count - @tparam Base the base iterator type to reverse. Valid types are @ref - iterator (to create @ref reverse_iterator) and @ref const_iterator (to - create @ref const_reverse_iterator). + @return Number of elements with key @a key. If the JSON value is not an + object, the return value will be `0`. + + @complexity Logarithmic in the size of the JSON object. - @requirement The class satisfies the following concept requirements: - - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator): - The iterator that can be moved to point (forward and backward) to any - element in constant time. - - [OutputIterator](http://en.cppreference.com/w/cpp/concept/OutputIterator): - It is possible to write to the pointed-to element (only if @a Base is - @ref iterator). + @liveexample{The example shows how `count()` is used.,count} @since version 1.0.0 */ - template - class json_reverse_iterator : public std::reverse_iterator + template + size_type count(KeyT&& key) const { - public: - /// shortcut to the reverse iterator adaptor - using base_iterator = std::reverse_iterator; - /// the reference type for the pointed-to element - using reference = typename Base::reference; - - /// create reverse iterator from iterator - json_reverse_iterator(const typename base_iterator::iterator_type& it) noexcept - : base_iterator(it) - {} - - /// create reverse iterator from base class - json_reverse_iterator(const base_iterator& it) noexcept - : base_iterator(it) - {} + // return 0 for all nonobject types + return is_object() ? m_value.object->count(std::forward(key)) : 0; + } - /// post-increment (it++) - json_reverse_iterator operator++(int) - { - return base_iterator::operator++(1); - } + /// @} - /// pre-increment (++it) - json_reverse_iterator& operator++() - { - base_iterator::operator++(); - return *this; - } - /// post-decrement (it--) - json_reverse_iterator operator--(int) - { - return base_iterator::operator--(1); - } + /////////////// + // iterators // + /////////////// - /// pre-decrement (--it) - json_reverse_iterator& operator--() - { - base_iterator::operator--(); - return *this; - } + /// @name iterators + /// @{ - /// add to iterator - json_reverse_iterator& operator+=(difference_type i) - { - base_iterator::operator+=(i); - return *this; - } + /*! + @brief returns an iterator to the first element - /// add to iterator - json_reverse_iterator operator+(difference_type i) const - { - auto result = *this; - result += i; - return result; - } + Returns an iterator to the first element. - /// subtract from iterator - json_reverse_iterator operator-(difference_type i) const - { - auto result = *this; - result -= i; - return result; - } + @image html range-begin-end.svg "Illustration from cppreference.com" - /// return difference - difference_type operator-(const json_reverse_iterator& other) const - { - return this->base() - other.base(); - } + @return iterator to the first element - /// access to successor - reference operator[](difference_type n) const - { - return *(this->operator+(n)); - } + @complexity Constant. - /// return the key of an object iterator - typename object_t::key_type key() const - { - auto it = --this->base(); - return it.key(); - } + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. - /// return the value of an iterator - reference value() const - { - auto it = --this->base(); - return it.operator * (); - } - }; + @liveexample{The following code shows an example for `begin()`.,begin} + @sa @ref cbegin() -- returns a const iterator to the beginning + @sa @ref end() -- returns an iterator to the end + @sa @ref cend() -- returns a const iterator to the end - private: - //////////////////// - // input adapters // - //////////////////// + @since version 1.0.0 + */ + iterator begin() noexcept + { + iterator result(this); + result.set_begin(); + return result; + } - /// abstract input adapter interface - class input_adapter + /*! + @copydoc basic_json::cbegin() + */ + const_iterator begin() const noexcept { - public: - virtual int get_character() = 0; - virtual std::string read(size_t offset, size_t length) = 0; - virtual ~input_adapter() {} + return cbegin(); + } - // native support + /*! + @brief returns a const iterator to the first element - /// input adapter for input stream - static std::shared_ptr create(std::istream& i, const size_t buffer_size = 16384) - { - return std::shared_ptr(new cached_input_stream_adapter(i, buffer_size)); - } + Returns a const iterator to the first element. - /// input adapter for input stream - static std::shared_ptr create(std::istream&& i, const size_t buffer_size = 16384) - { - return std::shared_ptr(new cached_input_stream_adapter(i, buffer_size)); - } + @image html range-begin-end.svg "Illustration from cppreference.com" - /// input adapter for buffer - static std::shared_ptr create(const char* b, size_t l) - { - return std::shared_ptr(new input_buffer_adapter(b, l)); - } + @return const iterator to the first element + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).begin()`. + + @liveexample{The following code shows an example for `cbegin()`.,cbegin} + + @sa @ref begin() -- returns an iterator to the beginning + @sa @ref end() -- returns an iterator to the end + @sa @ref cend() -- returns a const iterator to the end + + @since version 1.0.0 + */ + const_iterator cbegin() const noexcept + { + const_iterator result(this); + result.set_begin(); + return result; + } + + /*! + @brief returns an iterator to one past the last element - // derived support + Returns an iterator to one past the last element. - /// input adapter for string literal - template::value and - std::is_integral::type>::value and - sizeof(typename std::remove_pointer::type) == 1, int>::type = 0> - static std::shared_ptr create(CharT b) - { - return create(reinterpret_cast(b), - std::strlen(reinterpret_cast(b))); - } + @image html range-begin-end.svg "Illustration from cppreference.com" - /// input adapter for iterator range with contiguous storage - template::iterator_category, std::random_access_iterator_tag>::value - , int>::type - = 0> - static std::shared_ptr create(IteratorType first, IteratorType last) - { - // assertion to check that the iterator range is indeed contiguous, - // see http://stackoverflow.com/a/35008842/266378 for more discussion - assert(std::accumulate(first, last, std::pair(true, 0), - [&first](std::pair res, decltype(*first) val) - { - res.first &= (val == *(std::next(std::addressof(*first), res.second++))); - return res; - }).first); + @return iterator one past the last element - // assertion to check that each element is 1 byte long - static_assert(sizeof(typename std::iterator_traits::value_type) == 1, - "each element in the iterator range must have the size of 1 byte"); + @complexity Constant. - return create(reinterpret_cast(&(*first)), - static_cast(std::distance(first, last))); - } + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. - /// input adapter for array - template - static std::shared_ptr create(T (&array)[N]) - { - // delegate the call to the iterator-range overload - return create(std::begin(array), std::end(array)); - } + @liveexample{The following code shows an example for `end()`.,end} - /// input adapter for contiguous container - template::value and - std::is_base_of< - std::random_access_iterator_tag, - typename std::iterator_traits()))>::iterator_category>::value - , int>::type = 0> - static std::shared_ptr create(const ContiguousContainer& c) - { - // delegate the call to the iterator-range overload - return create(std::begin(c), std::end(c)); - } - }; + @sa @ref cend() -- returns a const iterator to the end + @sa @ref begin() -- returns an iterator to the beginning + @sa @ref cbegin() -- returns a const iterator to the beginning - /// a type to simplify interfaces - using input_adapter_t = std::shared_ptr; + @since version 1.0.0 + */ + iterator end() noexcept + { + iterator result(this); + result.set_end(); + return result; + } - /// input adapter for cached stream input - class cached_input_stream_adapter : public input_adapter + /*! + @copydoc basic_json::cend() + */ + const_iterator end() const noexcept { - public: - cached_input_stream_adapter(std::istream& i, const size_t buffer_size) - : is(i), start_position(is.tellg()), buffer(buffer_size, '\0') - { - // immediately abort if stream is erroneous - if (JSON_UNLIKELY(i.fail())) - { - JSON_THROW(parse_error::create(111, 0, "bad input stream")); - } + return cend(); + } - // initial fill - is.read(buffer.data(), static_cast(buffer.size())); - // store number of bytes in the buffer - fill_size = static_cast(is.gcount()); + /*! + @brief returns a const iterator to one past the last element - // skip byte order mark - if (fill_size >= 3 and buffer[0] == '\xEF' and buffer[1] == '\xBB' and buffer[2] == '\xBF') - { - buffer_pos += 3; - processed_chars += 3; - } - } + Returns a const iterator to one past the last element. - ~cached_input_stream_adapter() override - { - // clear stream flags - is.clear(); - // We initially read a lot of characters into the buffer, and we - // may not have processed all of them. Therefore, we need to - // "rewind" the stream after the last processed char. - is.seekg(start_position + static_cast(processed_chars)); - // clear stream flags - is.clear(); - } + @image html range-begin-end.svg "Illustration from cppreference.com" - int get_character() override - { - // check if refilling is necessary and possible - if (buffer_pos == fill_size and not eof) - { - // refill - is.read(buffer.data(), static_cast(buffer.size())); - // store number of bytes in the buffer - fill_size = static_cast(is.gcount()); + @return const iterator one past the last element - // the buffer is ready - buffer_pos = 0; + @complexity Constant. - // remember that filling did not yield new input - if (fill_size == 0) - { - eof = true; - return std::char_traits::eof(); - } - } + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).end()`. - ++processed_chars; - return buffer[buffer_pos++] & 0xFF;; - } + @liveexample{The following code shows an example for `cend()`.,cend} - std::string read(size_t offset, size_t length) override - { - // create buffer - std::string result(length, '\0'); + @sa @ref end() -- returns an iterator to the end + @sa @ref begin() -- returns an iterator to the beginning + @sa @ref cbegin() -- returns a const iterator to the beginning - // save stream position - auto current_pos = is.tellg(); - // save stream flags - auto flags = is.rdstate(); + @since version 1.0.0 + */ + const_iterator cend() const noexcept + { + const_iterator result(this); + result.set_end(); + return result; + } - // clear stream flags - is.clear(); - // set stream position - is.seekg(static_cast(offset)); - // read bytes - is.read(&result[0], static_cast(length)); + /*! + @brief returns an iterator to the reverse-beginning - // reset stream position - is.seekg(current_pos); - // reset stream flags - is.setstate(flags); + Returns an iterator to the reverse-beginning; that is, the last element. - return result; - } + @image html range-rbegin-rend.svg "Illustration from cppreference.com" - private: - /// the associated input stream - std::istream& is; + @complexity Constant. - /// chars returned via get_character() - size_t processed_chars = 0; - /// chars processed in the current buffer - size_t buffer_pos = 0; + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `reverse_iterator(end())`. - /// whether stream reached eof - bool eof = false; - /// how many chars have been copied to the buffer by last (re)fill - size_t fill_size = 0; + @liveexample{The following code shows an example for `rbegin()`.,rbegin} - /// position of the stream when we started - const std::streampos start_position; + @sa @ref crbegin() -- returns a const reverse iterator to the beginning + @sa @ref rend() -- returns a reverse iterator to the end + @sa @ref crend() -- returns a const reverse iterator to the end - /// internal buffer - std::vector buffer; - }; + @since version 1.0.0 + */ + reverse_iterator rbegin() noexcept + { + return reverse_iterator(end()); + } - /// input adapter for buffer input - class input_buffer_adapter : public input_adapter + /*! + @copydoc basic_json::crbegin() + */ + const_reverse_iterator rbegin() const noexcept { - public: - input_buffer_adapter(const char* b, size_t l) - : input_adapter(), cursor(b), limit(b + l), start(b) - { - // skip byte order mark - if (l >= 3 and b[0] == '\xEF' and b[1] == '\xBB' and b[2] == '\xBF') - { - cursor += 3; - } - } + return crbegin(); + } - // delete because of pointer members - input_buffer_adapter(const input_buffer_adapter&) = delete; - input_buffer_adapter& operator=(input_buffer_adapter&) = delete; + /*! + @brief returns an iterator to the reverse-end - int get_character() override - { - if (JSON_LIKELY(cursor < limit)) - { - return *(cursor++) & 0xFF; - } - else - { - return std::char_traits::eof(); - } - } + Returns an iterator to the reverse-end; that is, one before the first + element. - std::string read(size_t offset, size_t length) override - { - // avoid reading too many characters - const size_t max_length = static_cast(limit - start); - return std::string(start + offset, std::min(length, max_length - offset)); - } + @image html range-rbegin-rend.svg "Illustration from cppreference.com" - private: - /// pointer to the current character - const char* cursor; - /// pointer past the last character - const char* limit; - /// pointer to the first character - const char* start; - }; + @complexity Constant. - ////////////////////////////////////////// - // binary serialization/deserialization // - ////////////////////////////////////////// + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `reverse_iterator(begin())`. - /// @name binary serialization/deserialization support - /// @{ + @liveexample{The following code shows an example for `rend()`.,rend} + + @sa @ref crend() -- returns a const reverse iterator to the end + @sa @ref rbegin() -- returns a reverse iterator to the beginning + @sa @ref crbegin() -- returns a const reverse iterator to the beginning + + @since version 1.0.0 + */ + reverse_iterator rend() noexcept + { + return reverse_iterator(begin()); + } - private: /*! - @brief deserialization of CBOR and MessagePack values + @copydoc basic_json::crend() */ - class binary_reader + const_reverse_iterator rend() const noexcept { - public: - /*! - @brief create a binary reader + return crend(); + } - @param[in] adapter input adapter to read from - */ - explicit binary_reader(input_adapter_t adapter) - : ia(adapter), is_little_endian(little_endianess()) - { - assert(ia); - } + /*! + @brief returns a const reverse iterator to the last element - /*! - @brief create a JSON value from CBOR input + Returns a const iterator to the reverse-beginning; that is, the last + element. - @param[in] get_char whether a new character should be retrieved from - the input (true, default) or whether the last - read character should be considered instead + @image html range-rbegin-rend.svg "Illustration from cppreference.com" - @return JSON value created from CBOR input + @complexity Constant. - @throw parse_error.110 if input ended unexpectedly - @throw parse_error.112 if unsupported byte was read - */ - basic_json parse_cbor(const bool get_char = true) - { - switch (get_char ? get() : current) - { - // EOF - case std::char_traits::eof(): - { - JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - } + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).rbegin()`. - // Integer 0x00..0x17 (0..23) - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - { - return static_cast(current); - } + @liveexample{The following code shows an example for `crbegin()`.,crbegin} - case 0x18: // Unsigned integer (one-byte uint8_t follows) - { - return get_number(); - } + @sa @ref rbegin() -- returns a reverse iterator to the beginning + @sa @ref rend() -- returns a reverse iterator to the end + @sa @ref crend() -- returns a const reverse iterator to the end - case 0x19: // Unsigned integer (two-byte uint16_t follows) - { - return get_number(); - } + @since version 1.0.0 + */ + const_reverse_iterator crbegin() const noexcept + { + return const_reverse_iterator(cend()); + } - case 0x1a: // Unsigned integer (four-byte uint32_t follows) - { - return get_number(); - } + /*! + @brief returns a const reverse iterator to one before the first - case 0x1b: // Unsigned integer (eight-byte uint64_t follows) - { - return get_number(); - } + Returns a const reverse iterator to the reverse-end; that is, one before + the first element. - // Negative integer -1-0x00..-1-0x17 (-1..-24) - case 0x20: - case 0x21: - case 0x22: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - { - return static_cast(0x20 - 1 - current); - } + @image html range-rbegin-rend.svg "Illustration from cppreference.com" + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).rend()`. + + @liveexample{The following code shows an example for `crend()`.,crend} + + @sa @ref rend() -- returns a reverse iterator to the end + @sa @ref rbegin() -- returns a reverse iterator to the beginning + @sa @ref crbegin() -- returns a const reverse iterator to the beginning + + @since version 1.0.0 + */ + const_reverse_iterator crend() const noexcept + { + return const_reverse_iterator(cbegin()); + } - case 0x38: // Negative integer (one-byte uint8_t follows) - { - // must be uint8_t ! - return static_cast(-1) - get_number(); - } + public: + /*! + @brief wrapper to access iterator member functions in range-based for - case 0x39: // Negative integer -1-n (two-byte uint16_t follows) - { - return static_cast(-1) - get_number(); - } + This function allows to access @ref iterator::key() and @ref + iterator::value() during range-based for loops. In these loops, a + reference to the JSON values is returned, so there is no access to the + underlying iterator. - case 0x3a: // Negative integer -1-n (four-byte uint32_t follows) - { - return static_cast(-1) - get_number(); - } + For loop without iterator_wrapper: - case 0x3b: // Negative integer -1-n (eight-byte uint64_t follows) - { - return static_cast(-1) - static_cast(get_number()); - } + @code{cpp} + for (auto it = j_object.begin(); it != j_object.end(); ++it) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode - // UTF-8 string (0x00..0x17 bytes follow) - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - case 0x78: // UTF-8 string (one-byte uint8_t for n follows) - case 0x79: // UTF-8 string (two-byte uint16_t for n follow) - case 0x7a: // UTF-8 string (four-byte uint32_t for n follow) - case 0x7b: // UTF-8 string (eight-byte uint64_t for n follow) - case 0x7f: // UTF-8 string (indefinite length) - { - return get_cbor_string(); - } - - // array (0x00..0x17 data items follow) - case 0x80: - case 0x81: - case 0x82: - case 0x83: - case 0x84: - case 0x85: - case 0x86: - case 0x87: - case 0x88: - case 0x89: - case 0x8a: - case 0x8b: - case 0x8c: - case 0x8d: - case 0x8e: - case 0x8f: - case 0x90: - case 0x91: - case 0x92: - case 0x93: - case 0x94: - case 0x95: - case 0x96: - case 0x97: - { - basic_json result = value_t::array; - const auto len = static_cast(current & 0x1f); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + Range-based for loop without iterator proxy: - case 0x98: // array (one-byte uint8_t for n follows) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + @code{cpp} + for (auto it : j_object) + { + // "it" is of type json::reference and has no key() member + std::cout << "value: " << it << '\n'; + } + @endcode - case 0x99: // array (two-byte uint16_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + Range-based for loop with iterator proxy: - case 0x9a: // array (four-byte uint32_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + @code{cpp} + for (auto it : json::iterator_wrapper(j_object)) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode - case 0x9b: // array (eight-byte uint64_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + @note When iterating over an array, `key()` will return the index of the + element as string (see example). - case 0x9f: // array (indefinite length) - { - basic_json result = value_t::array; - while (get() != 0xff) - { - result.push_back(parse_cbor(false)); - } - return result; - } - - // map (0x00..0x17 pairs of data items follow) - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - { - basic_json result = value_t::object; - const auto len = static_cast(current & 0x1f); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @param[in] ref reference to a JSON value + @return iteration proxy object wrapping @a ref with an interface to use in + range-based for loops - case 0xb8: // map (one-byte uint8_t for n follows) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @liveexample{The following code shows how the wrapper is used,iterator_wrapper} - case 0xb9: // map (two-byte uint16_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. - case 0xba: // map (four-byte uint32_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @complexity Constant. - case 0xbb: // map (eight-byte uint64_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @note The name of this function is not yet final and may change in the + future. - case 0xbf: // map (indefinite length) - { - basic_json result = value_t::object; - while (get() != 0xff) - { - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @deprecated This stream operator is deprecated and will be removed in + future 4.0.0 of the library. Please use @ref items() instead; + that is, replace `json::iterator_wrapper(j)` with `j.items()`. + */ + JSON_DEPRECATED + static iteration_proxy iterator_wrapper(reference ref) noexcept + { + return ref.items(); + } - case 0xf4: // false - { - return false; - } + /*! + @copydoc iterator_wrapper(reference) + */ + JSON_DEPRECATED + static iteration_proxy iterator_wrapper(const_reference ref) noexcept + { + return ref.items(); + } - case 0xf5: // true - { - return true; - } + /*! + @brief helper to access iterator member functions in range-based for - case 0xf6: // null - { - return value_t::null; - } + This function allows to access @ref iterator::key() and @ref + iterator::value() during range-based for loops. In these loops, a + reference to the JSON values is returned, so there is no access to the + underlying iterator. - case 0xf9: // Half-Precision Float (two-byte IEEE 754) - { - const int byte1 = get(); - check_eof(); - const int byte2 = get(); - check_eof(); + For loop without `items()` function: - // code from RFC 7049, Appendix D, Figure 3: - // As half-precision floating-point numbers were only added - // to IEEE 754 in 2008, today's programming platforms often - // still only have limited support for them. It is very - // easy to include at least decoding support for them even - // without such support. An example of a small decoder for - // half-precision floating-point numbers in the C language - // is shown in Fig. 3. - const int half = (byte1 << 8) + byte2; - const int exp = (half >> 10) & 0x1f; - const int mant = half & 0x3ff; - double val; - if (exp == 0) - { - val = std::ldexp(mant, -24); - } - else if (exp != 31) - { - val = std::ldexp(mant + 1024, exp - 25); - } - else - { - val = mant == 0 - ? std::numeric_limits::infinity() - : std::numeric_limits::quiet_NaN(); - } - return (half & 0x8000) != 0 ? -val : val; - } + @code{cpp} + for (auto it = j_object.begin(); it != j_object.end(); ++it) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode - case 0xfa: // Single-Precision Float (four-byte IEEE 754) - { - return get_number(); - } + Range-based for loop without `items()` function: - case 0xfb: // Double-Precision Float (eight-byte IEEE 754) - { - return get_number(); - } + @code{cpp} + for (auto it : j_object) + { + // "it" is of type json::reference and has no key() member + std::cout << "value: " << it << '\n'; + } + @endcode - default: // anything else (0xFF is handled inside the other types) - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(112, chars_read, "error reading CBOR; last byte: 0x" + ss.str())); - } - } - } + Range-based for loop with `items()` function: - /*! - @brief create a JSON value from MessagePack input + @code{cpp} + for (auto it : j_object.items()) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode - @return JSON value created from MessagePack input + @note When iterating over an array, `key()` will return the index of the + element as string (see example). For primitive types (e.g., numbers), + `key()` returns an empty string. - @throw parse_error.110 if input ended unexpectedly - @throw parse_error.112 if unsupported byte was read - */ - basic_json parse_msgpack() - { - switch (get()) - { - // EOF - case std::char_traits::eof(): - { - JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - } + @return iteration proxy object wrapping @a ref with an interface to use in + range-based for loops - // positive fixint - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - case 0x20: - case 0x21: - case 0x22: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - case 0x38: - case 0x39: - case 0x3a: - case 0x3b: - case 0x3c: - case 0x3d: - case 0x3e: - case 0x3f: - case 0x40: - case 0x41: - case 0x42: - case 0x43: - case 0x44: - case 0x45: - case 0x46: - case 0x47: - case 0x48: - case 0x49: - case 0x4a: - case 0x4b: - case 0x4c: - case 0x4d: - case 0x4e: - case 0x4f: - case 0x50: - case 0x51: - case 0x52: - case 0x53: - case 0x54: - case 0x55: - case 0x56: - case 0x57: - case 0x58: - case 0x59: - case 0x5a: - case 0x5b: - case 0x5c: - case 0x5d: - case 0x5e: - case 0x5f: - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - case 0x78: - case 0x79: - case 0x7a: - case 0x7b: - case 0x7c: - case 0x7d: - case 0x7e: - case 0x7f: - { - return static_cast(current); - } - - // fixmap - case 0x80: - case 0x81: - case 0x82: - case 0x83: - case 0x84: - case 0x85: - case 0x86: - case 0x87: - case 0x88: - case 0x89: - case 0x8a: - case 0x8b: - case 0x8c: - case 0x8d: - case 0x8e: - case 0x8f: - { - basic_json result = value_t::object; - const auto len = static_cast(current & 0x0f); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_msgpack_string(); - result[key] = parse_msgpack(); - } - return result; - } - - // fixarray - case 0x90: - case 0x91: - case 0x92: - case 0x93: - case 0x94: - case 0x95: - case 0x96: - case 0x97: - case 0x98: - case 0x99: - case 0x9a: - case 0x9b: - case 0x9c: - case 0x9d: - case 0x9e: - case 0x9f: - { - basic_json result = value_t::array; - const auto len = static_cast(current & 0x0f); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_msgpack()); - } - return result; - } - - // fixstr - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - case 0xb8: - case 0xb9: - case 0xba: - case 0xbb: - case 0xbc: - case 0xbd: - case 0xbe: - case 0xbf: - { - return get_msgpack_string(); - } - - case 0xc0: // nil - { - return value_t::null; - } - - case 0xc2: // false - { - return false; - } + @liveexample{The following code shows how the function is used.,items} + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Constant. + + @since version 3.x.x. + */ + iteration_proxy items() noexcept + { + return iteration_proxy(*this); + } + + /*! + @copydoc items() + */ + iteration_proxy items() const noexcept + { + return iteration_proxy(*this); + } + + /// @} - case 0xc3: // true - { - return true; - } - case 0xca: // float 32 - { - return get_number(); - } + ////////////// + // capacity // + ////////////// - case 0xcb: // float 64 - { - return get_number(); - } + /// @name capacity + /// @{ - case 0xcc: // uint 8 - { - return get_number(); - } + /*! + @brief checks whether the container is empty. - case 0xcd: // uint 16 - { - return get_number(); - } + Checks if a JSON value has no elements (i.e. whether its @ref size is `0`). - case 0xce: // uint 32 - { - return get_number(); - } + @return The return value depends on the different types and is + defined as follows: + Value type | return value + ----------- | ------------- + null | `true` + boolean | `false` + string | `false` + number | `false` + object | result of function `object_t::empty()` + array | result of function `array_t::empty()` - case 0xcf: // uint 64 - { - return get_number(); - } + @liveexample{The following code uses `empty()` to check if a JSON + object contains any elements.,empty} - case 0xd0: // int 8 - { - return get_number(); - } + @complexity Constant, as long as @ref array_t and @ref object_t satisfy + the Container concept; that is, their `empty()` functions have constant + complexity. - case 0xd1: // int 16 - { - return get_number(); - } + @iterators No changes. - case 0xd2: // int 32 - { - return get_number(); - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - case 0xd3: // int 64 - { - return get_number(); - } + @note This function does not return whether a string stored as JSON value + is empty - it returns whether the JSON container itself is empty which is + false in the case of a string. - case 0xd9: // str 8 - case 0xda: // str 16 - case 0xdb: // str 32 - { - return get_msgpack_string(); - } + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of `begin() == end()`. - case 0xdc: // array 16 - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_msgpack()); - } - return result; - } + @sa @ref size() -- returns the number of elements - case 0xdd: // array 32 - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_msgpack()); - } - return result; - } + @since version 1.0.0 + */ + bool empty() const noexcept + { + switch (m_type) + { + case value_t::null: + { + // null values are empty + return true; + } - case 0xde: // map 16 - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_msgpack_string(); - result[key] = parse_msgpack(); - } - return result; - } + case value_t::array: + { + // delegate call to array_t::empty() + return m_value.array->empty(); + } - case 0xdf: // map 32 - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_msgpack_string(); - result[key] = parse_msgpack(); - } - return result; - } - - // positive fixint - case 0xe0: - case 0xe1: - case 0xe2: - case 0xe3: - case 0xe4: - case 0xe5: - case 0xe6: - case 0xe7: - case 0xe8: - case 0xe9: - case 0xea: - case 0xeb: - case 0xec: - case 0xed: - case 0xee: - case 0xef: - case 0xf0: - case 0xf1: - case 0xf2: - case 0xf3: - case 0xf4: - case 0xf5: - case 0xf6: - case 0xf7: - case 0xf8: - case 0xf9: - case 0xfa: - case 0xfb: - case 0xfc: - case 0xfd: - case 0xfe: - case 0xff: - { - return static_cast(current); - } - - default: // anything else - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(112, chars_read, "error reading MessagePack; last byte: 0x" + ss.str())); - } + case value_t::object: + { + // delegate call to object_t::empty() + return m_value.object->empty(); + } + + default: + { + // all other types are nonempty + return false; } } + } - /*! - @brief determine system byte order + /*! + @brief returns the number of elements - @return true iff system's byte order is little endian + Returns the number of elements in a JSON value. - @note from http://stackoverflow.com/a/1001328/266378 - */ - static bool little_endianess() noexcept - { - int num = 1; - return (*reinterpret_cast(&num) == 1); - } + @return The return value depends on the different types and is + defined as follows: + Value type | return value + ----------- | ------------- + null | `0` + boolean | `1` + string | `1` + number | `1` + object | result of function object_t::size() + array | result of function array_t::size() - private: - /*! - @brief get next character from the input + @liveexample{The following code calls `size()` on the different value + types.,size} - This function provides the interface to the used input adapter. It does - not throw in case the input reached EOF, but returns - `std::char_traits::eof()` in that case. + @complexity Constant, as long as @ref array_t and @ref object_t satisfy + the Container concept; that is, their size() functions have constant + complexity. - @return character read from the input - */ - int get() - { - ++chars_read; - return (current = ia->get_character()); - } + @iterators No changes. - /* - @brief read a number from the input + @exceptionsafety No-throw guarantee: this function never throws exceptions. - @tparam T the type of the number + @note This function does not return the length of a string stored as JSON + value - it returns the number of elements in the JSON value which is 1 in + the case of a string. - @return number of type @a T + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of `std::distance(begin(), end())`. - @note This function needs to respect the system's endianess, because - bytes in CBOR and MessagePack are stored in network order (big - endian) and therefore need reordering on little endian systems. + @sa @ref empty() -- checks whether the container is empty + @sa @ref max_size() -- returns the maximal number of elements - @throw parse_error.110 if input has less than `sizeof(T)` bytes - */ - template - T get_number() + @since version 1.0.0 + */ + size_type size() const noexcept + { + switch (m_type) { - // step 1: read input into array with system's byte order - std::array vec; - for (size_t i = 0; i < sizeof(T); ++i) + case value_t::null: { - get(); - check_eof(); + // null values are empty + return 0; + } - // reverse byte order prior to conversion if necessary - if (is_little_endian) - { - vec[sizeof(T) - i - 1] = static_cast(current); - } - else - { - vec[i] = static_cast(current); - } + case value_t::array: + { + // delegate call to array_t::size() + return m_value.array->size(); } - // step 2: convert array into number of type T and return - T result; - std::memcpy(&result, vec.data(), sizeof(T)); - return result; + case value_t::object: + { + // delegate call to object_t::size() + return m_value.object->size(); + } + + default: + { + // all other types have size 1 + return 1; + } } + } + + /*! + @brief returns the maximum possible number of elements + + Returns the maximum number of elements a JSON value is able to hold due to + system or library implementation limitations, i.e. `std::distance(begin(), + end())` for the JSON value. + + @return The return value depends on the different types and is + defined as follows: + Value type | return value + ----------- | ------------- + null | `0` (same as `size()`) + boolean | `1` (same as `size()`) + string | `1` (same as `size()`) + number | `1` (same as `size()`) + object | result of function `object_t::max_size()` + array | result of function `array_t::max_size()` + + @liveexample{The following code calls `max_size()` on the different value + types. Note the output is implementation specific.,max_size} + + @complexity Constant, as long as @ref array_t and @ref object_t satisfy + the Container concept; that is, their `max_size()` functions have constant + complexity. + + @iterators No changes. - /*! - @brief create a string by reading characters from the input + @exceptionsafety No-throw guarantee: this function never throws exceptions. - @param[in] len number of bytes to read + @requirement This function helps `basic_json` satisfying the + [Container](http://en.cppreference.com/w/cpp/concept/Container) + requirements: + - The complexity is constant. + - Has the semantics of returning `b.size()` where `b` is the largest + possible JSON value. - @return string created by reading @a len bytes + @sa @ref size() -- returns the number of elements - @throw parse_error.110 if input has less than @a len bytes - */ - std::string get_string(const size_t len) + @since version 1.0.0 + */ + size_type max_size() const noexcept + { + switch (m_type) { - std::string result; - for (size_t i = 0; i < len; ++i) + case value_t::array: { - get(); - check_eof(); - result.append(1, static_cast(current)); + // delegate call to array_t::max_size() + return m_value.array->max_size(); } - return result; - } - /*! - @brief reads a CBOR string + case value_t::object: + { + // delegate call to object_t::max_size() + return m_value.object->max_size(); + } - This function first reads starting bytes to determine the expected - string length and then copies this number of bytes into a string. - Additionally, CBOR's strings with indefinite lengths are supported. + default: + { + // all other types have max_size() == size() + return size(); + } + } + } - @return string + /// @} - @throw parse_error.110 if input ended - @throw parse_error.113 if an unexpexted byte is read - */ - std::string get_cbor_string() - { - check_eof(); - switch (current) - { - // UTF-8 string (0x00..0x17 bytes follow) - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - { - const auto len = static_cast(current & 0x1f); - return get_string(len); - } + /////////////// + // modifiers // + /////////////// - case 0x78: // UTF-8 string (one-byte uint8_t for n follows) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + /// @name modifiers + /// @{ - case 0x79: // UTF-8 string (two-byte uint16_t for n follow) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + /*! + @brief clears the contents - case 0x7a: // UTF-8 string (four-byte uint32_t for n follow) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + Clears the content of a JSON value and resets it to the default value as + if @ref basic_json(value_t) would have been called with the current value + type from @ref type(): + + Value type | initial value + ----------- | ------------- + null | `null` + boolean | `false` + string | `""` + number | `0` + object | `{}` + array | `[]` - case 0x7b: // UTF-8 string (eight-byte uint64_t for n follow) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @post Has the same effect as calling + @code {.cpp} + *this = basic_json(type()); + @endcode - case 0x7f: // UTF-8 string (indefinite length) - { - std::string result; - while (get() != 0xff) - { - check_eof(); - result.append(1, static_cast(current)); - } - return result; - } + @liveexample{The example below shows the effect of `clear()` to different + JSON types.,clear} - default: - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(113, chars_read, "expected a CBOR string; last byte: 0x" + ss.str())); - } - } - } + @complexity Linear in the size of the JSON value. - /*! - @brief reads a MessagePack string + @iterators All iterators, pointers and references related to this container + are invalidated. - This function first reads starting bytes to determine the expected - string length and then copies this number of bytes into a string. + @exceptionsafety No-throw guarantee: this function never throws exceptions. - @return string + @sa @ref basic_json(value_t) -- constructor that creates an object with the + same value than calling `clear()` - @throw parse_error.110 if input ended - @throw parse_error.113 if an unexpexted byte is read - */ - std::string get_msgpack_string() + @since version 1.0.0 + */ + void clear() noexcept + { + switch (m_type) { - check_eof(); + case value_t::number_integer: + { + m_value.number_integer = 0; + break; + } - switch (current) + case value_t::number_unsigned: { - // fixstr - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - case 0xb8: - case 0xb9: - case 0xba: - case 0xbb: - case 0xbc: - case 0xbd: - case 0xbe: - case 0xbf: - { - const auto len = static_cast(current & 0x1f); - return get_string(len); - } + m_value.number_unsigned = 0; + break; + } - case 0xd9: // str 8 - { - const auto len = static_cast(get_number()); - return get_string(len); - } + case value_t::number_float: + { + m_value.number_float = 0.0; + break; + } - case 0xda: // str 16 - { - const auto len = static_cast(get_number()); - return get_string(len); - } + case value_t::boolean: + { + m_value.boolean = false; + break; + } - case 0xdb: // str 32 - { - const auto len = static_cast(get_number()); - return get_string(len); - } + case value_t::string: + { + m_value.string->clear(); + break; + } - default: - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(113, chars_read, "expected a MessagePack string; last byte: 0x" + ss.str())); - } + case value_t::array: + { + m_value.array->clear(); + break; } - } - /*! - @brief check if input ended - @throw parse_error.110 if input ended - */ - void check_eof() const - { - if (JSON_UNLIKELY(current == std::char_traits::eof())) + case value_t::object: { - JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); + m_value.object->clear(); + break; } + + default: + break; } + } - private: - /// input adapter - input_adapter_t ia = nullptr; + /*! + @brief add an object to an array - /// the current character - int current = std::char_traits::eof(); + Appends the given element @a val to the end of the JSON value. If the + function is called on a JSON null value, an empty array is created before + appending @a val. - /// the number of characters read - size_t chars_read = 0; + @param[in] val the value to add to the JSON array - /// whether we can assume little endianess - const bool is_little_endian = true; - }; + @throw type_error.308 when called on a type other than JSON array or + null; example: `"cannot use push_back() with number"` - /*! - @brief serialization to CBOR and MessagePack values + @complexity Amortized constant. + + @liveexample{The example shows how `push_back()` and `+=` can be used to + add elements to a JSON array. Note how the `null` value was silently + converted to a JSON array.,push_back} + + @since version 1.0.0 */ - class binary_writer + void push_back(basic_json&& val) { - public: - /*! - @brief create a binary writer - - @param[in] adapter output adapter to write to - */ - explicit binary_writer(output_adapter_t adapter) - : is_little_endian(binary_reader::little_endianess()), oa(adapter) + // push_back only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_array()))) { - assert(oa); + JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name()))); } - /*! - @brief[in] j JSON value to serialize - */ - void write_cbor(const basic_json& j) + // transform null object into an array + if (is_null()) { - switch (j.type()) - { - case value_t::null: - { - oa->write_character(0xf6); - break; - } - - case value_t::boolean: - { - oa->write_character(j.m_value.boolean ? 0xf5 : 0xf4); - break; - } - - case value_t::number_integer: - { - if (j.m_value.number_integer >= 0) - { - // CBOR does not differentiate between positive signed - // integers and unsigned integers. Therefore, we used the - // code from the value_t::number_unsigned case here. - if (j.m_value.number_integer <= 0x17) - { - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer <= (std::numeric_limits::max)()) - { - oa->write_character(0x18); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer <= (std::numeric_limits::max)()) - { - oa->write_character(0x19); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer <= (std::numeric_limits::max)()) - { - oa->write_character(0x1a); - write_number(static_cast(j.m_value.number_integer)); - } - else - { - oa->write_character(0x1b); - write_number(static_cast(j.m_value.number_integer)); - } - } - else - { - // The conversions below encode the sign in the first - // byte, and the value is converted to a positive number. - const auto positive_number = -1 - j.m_value.number_integer; - if (j.m_value.number_integer >= -24) - { - write_number(static_cast(0x20 + positive_number)); - } - else if (positive_number <= (std::numeric_limits::max)()) - { - oa->write_character(0x38); - write_number(static_cast(positive_number)); - } - else if (positive_number <= (std::numeric_limits::max)()) - { - oa->write_character(0x39); - write_number(static_cast(positive_number)); - } - else if (positive_number <= (std::numeric_limits::max)()) - { - oa->write_character(0x3a); - write_number(static_cast(positive_number)); - } - else - { - oa->write_character(0x3b); - write_number(static_cast(positive_number)); - } - } - break; - } + m_type = value_t::array; + m_value = value_t::array; + assert_invariant(); + } - case value_t::number_unsigned: - { - if (j.m_value.number_unsigned <= 0x17) - { - write_number(static_cast(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - oa->write_character(0x18); - write_number(static_cast(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - oa->write_character(0x19); - write_number(static_cast(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - oa->write_character(0x1a); - write_number(static_cast(j.m_value.number_unsigned)); - } - else - { - oa->write_character(0x1b); - write_number(static_cast(j.m_value.number_unsigned)); - } - break; - } + // add element to array (move semantics) + m_value.array->push_back(std::move(val)); + // invalidate object + val.m_type = value_t::null; + } - case value_t::number_float: - { - // Double-Precision Float - oa->write_character(0xfb); - write_number(j.m_value.number_float); - break; - } + /*! + @brief add an object to an array + @copydoc push_back(basic_json&&) + */ + reference operator+=(basic_json&& val) + { + push_back(std::move(val)); + return *this; + } - case value_t::string: - { - // step 1: write control byte and the string length - const auto N = j.m_value.string->size(); - if (N <= 0x17) - { - write_number(static_cast(0x60 + N)); - } - else if (N <= 0xff) - { - oa->write_character(0x78); - write_number(static_cast(N)); - } - else if (N <= 0xffff) - { - oa->write_character(0x79); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - oa->write_character(0x7a); - write_number(static_cast(N)); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - oa->write_character(0x7b); - write_number(static_cast(N)); - } - // LCOV_EXCL_STOP + /*! + @brief add an object to an array + @copydoc push_back(basic_json&&) + */ + void push_back(const basic_json& val) + { + // push_back only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_array()))) + { + JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name()))); + } - // step 2: write the string - oa->write_characters(reinterpret_cast(j.m_value.string->c_str()), - j.m_value.string->size()); - break; - } + // transform null object into an array + if (is_null()) + { + m_type = value_t::array; + m_value = value_t::array; + assert_invariant(); + } - case value_t::array: - { - // step 1: write control byte and the array size - const auto N = j.m_value.array->size(); - if (N <= 0x17) - { - write_number(static_cast(0x80 + N)); - } - else if (N <= 0xff) - { - oa->write_character(0x98); - write_number(static_cast(N)); - } - else if (N <= 0xffff) - { - oa->write_character(0x99); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - oa->write_character(0x9a); - write_number(static_cast(N)); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - oa->write_character(0x9b); - write_number(static_cast(N)); - } - // LCOV_EXCL_STOP + // add element to array + m_value.array->push_back(val); + } - // step 2: write each element - for (const auto& el : *j.m_value.array) - { - write_cbor(el); - } - break; - } + /*! + @brief add an object to an array + @copydoc push_back(basic_json&&) + */ + reference operator+=(const basic_json& val) + { + push_back(val); + return *this; + } - case value_t::object: - { - // step 1: write control byte and the object size - const auto N = j.m_value.object->size(); - if (N <= 0x17) - { - write_number(static_cast(0xa0 + N)); - } - else if (N <= 0xff) - { - oa->write_character(0xb8); - write_number(static_cast(N)); - } - else if (N <= 0xffff) - { - oa->write_character(0xb9); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - oa->write_character(0xba); - write_number(static_cast(N)); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - oa->write_character(0xbb); - write_number(static_cast(N)); - } - // LCOV_EXCL_STOP + /*! + @brief add an object to an object - // step 2: write each element - for (const auto& el : *j.m_value.object) - { - write_cbor(el.first); - write_cbor(el.second); - } - break; - } + Inserts the given element @a val to the JSON object. If the function is + called on a JSON null value, an empty object is created before inserting + @a val. - default: - { - break; - } - } - } + @param[in] val the value to add to the JSON object - /*! - @brief[in] j JSON value to serialize - */ - void write_msgpack(const basic_json& j) - { - switch (j.type()) - { - case value_t::null: - { - // nil - oa->write_character(0xc0); - break; - } + @throw type_error.308 when called on a type other than JSON object or + null; example: `"cannot use push_back() with number"` - case value_t::boolean: - { - // true and false - oa->write_character(j.m_value.boolean ? 0xc3 : 0xc2); - break; - } + @complexity Logarithmic in the size of the container, O(log(`size()`)). - case value_t::number_integer: - { - if (j.m_value.number_integer >= 0) - { - // MessagePack does not differentiate between positive - // signed integers and unsigned integers. Therefore, we - // used the code from the value_t::number_unsigned case - // here. - if (j.m_value.number_unsigned < 128) - { - // positive fixnum - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 8 - oa->write_character(0xcc); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 16 - oa->write_character(0xcd); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 32 - oa->write_character(0xce); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 64 - oa->write_character(0xcf); - write_number(static_cast(j.m_value.number_integer)); - } - } - else - { - if (j.m_value.number_integer >= -32) - { - // negative fixnum - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 8 - oa->write_character(0xd0); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 16 - oa->write_character(0xd1); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 32 - oa->write_character(0xd2); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 64 - oa->write_character(0xd3); - write_number(static_cast(j.m_value.number_integer)); - } - } - break; - } + @liveexample{The example shows how `push_back()` and `+=` can be used to + add elements to a JSON object. Note how the `null` value was silently + converted to a JSON object.,push_back__object_t__value} - case value_t::number_unsigned: - { - if (j.m_value.number_unsigned < 128) - { - // positive fixnum - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 8 - oa->write_character(0xcc); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 16 - oa->write_character(0xcd); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 32 - oa->write_character(0xce); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 64 - oa->write_character(0xcf); - write_number(static_cast(j.m_value.number_integer)); - } - break; - } + @since version 1.0.0 + */ + void push_back(const typename object_t::value_type& val) + { + // push_back only works for null objects or objects + if (JSON_UNLIKELY(not(is_null() or is_object()))) + { + JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name()))); + } - case value_t::number_float: - { - // float 64 - oa->write_character(0xcb); - write_number(j.m_value.number_float); - break; - } + // transform null object into an object + if (is_null()) + { + m_type = value_t::object; + m_value = value_t::object; + assert_invariant(); + } - case value_t::string: - { - // step 1: write control byte and the string length - const auto N = j.m_value.string->size(); - if (N <= 31) - { - // fixstr - write_number(static_cast(0xa0 | N)); - } - else if (N <= 255) - { - // str 8 - oa->write_character(0xd9); - write_number(static_cast(N)); - } - else if (N <= 65535) - { - // str 16 - oa->write_character(0xda); - write_number(static_cast(N)); - } - else if (N <= 4294967295) - { - // str 32 - oa->write_character(0xdb); - write_number(static_cast(N)); - } + // add element to array + m_value.object->insert(val); + } - // step 2: write the string - oa->write_characters(reinterpret_cast(j.m_value.string->c_str()), - j.m_value.string->size()); - break; - } + /*! + @brief add an object to an object + @copydoc push_back(const typename object_t::value_type&) + */ + reference operator+=(const typename object_t::value_type& val) + { + push_back(val); + return *this; + } - case value_t::array: - { - // step 1: write control byte and the array size - const auto N = j.m_value.array->size(); - if (N <= 15) - { - // fixarray - write_number(static_cast(0x90 | N)); - } - else if (N <= 0xffff) - { - // array 16 - oa->write_character(0xdc); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - // array 32 - oa->write_character(0xdd); - write_number(static_cast(N)); - } + /*! + @brief add an object to an object - // step 2: write each element - for (const auto& el : *j.m_value.array) - { - write_msgpack(el); - } - break; - } + This function allows to use `push_back` with an initializer list. In case - case value_t::object: - { - // step 1: write control byte and the object size - const auto N = j.m_value.object->size(); - if (N <= 15) - { - // fixmap - write_number(static_cast(0x80 | (N & 0xf))); - } - else if (N <= 65535) - { - // map 16 - oa->write_character(0xde); - write_number(static_cast(N)); - } - else if (N <= 4294967295) - { - // map 32 - oa->write_character(0xdf); - write_number(static_cast(N)); - } + 1. the current value is an object, + 2. the initializer list @a init contains only two elements, and + 3. the first element of @a init is a string, - // step 2: write each element - for (const auto& el : *j.m_value.object) - { - write_msgpack(el.first); - write_msgpack(el.second); - } - break; - } + @a init is converted into an object element and added using + @ref push_back(const typename object_t::value_type&). Otherwise, @a init + is converted to a JSON value and added using @ref push_back(basic_json&&). - default: - { - break; - } - } - } + @param[in] init an initializer list - private: - /* - @brief write a number to output input + @complexity Linear in the size of the initializer list @a init. - @param[in] n number of type @a T - @tparam T the type of the number + @note This function is required to resolve an ambiguous overload error, + because pairs like `{"key", "value"}` can be both interpreted as + `object_t::value_type` or `std::initializer_list`, see + https://github.com/nlohmann/json/issues/235 for more information. - @note This function needs to respect the system's endianess, because - bytes in CBOR and MessagePack are stored in network order (big - endian) and therefore need reordering on little endian systems. - */ - template - void write_number(T n) + @liveexample{The example shows how initializer lists are treated as + objects when possible.,push_back__initializer_list} + */ + void push_back(initializer_list_t init) + { + if (is_object() and init.size() == 2 and (*init.begin())->is_string()) { - // step 1: write number to array of length T - std::array vec; - std::memcpy(vec.data(), &n, sizeof(T)); - - // step 2: write array to output (with possible reordering) - for (size_t i = 0; i < sizeof(T); ++i) - { - // reverse byte order prior to conversion if necessary - if (is_little_endian) - { - oa->write_character(vec[sizeof(T) - i - 1]); - } - else - { - oa->write_character(vec[i]); - } - } + basic_json&& key = init.begin()->moved_or_copied(); + push_back(typename object_t::value_type( + std::move(key.get_ref()), (init.begin() + 1)->moved_or_copied())); } + else + { + push_back(basic_json(init)); + } + } - private: - /// whether we can assume little endianess - const bool is_little_endian = true; - - /// the output - output_adapter_t oa = nullptr; - }; + /*! + @brief add an object to an object + @copydoc push_back(initializer_list_t) + */ + reference operator+=(initializer_list_t init) + { + push_back(init); + return *this; + } - public: /*! - @brief create a CBOR serialization of a given JSON value + @brief add an object to an array - Serializes a given JSON value @a j to a byte vector using the CBOR (Concise - Binary Object Representation) serialization format. CBOR is a binary - serialization format which aims to be more compact than JSON itself, yet - more efficient to parse. + Creates a JSON value from the passed parameters @a args to the end of the + JSON value. If the function is called on a JSON null value, an empty array + is created before appending the value created from @a args. - The library uses the following mapping from JSON values types to - CBOR types according to the CBOR specification (RFC 7049): + @param[in] args arguments to forward to a constructor of @ref basic_json + @tparam Args compatible types to create a @ref basic_json object - JSON value type | value/range | CBOR type | first byte - --------------- | ------------------------------------------ | ---------------------------------- | --------------- - null | `null` | Null | 0xf6 - boolean | `true` | True | 0xf5 - boolean | `false` | False | 0xf4 - number_integer | -9223372036854775808..-2147483649 | Negative integer (8 bytes follow) | 0x3b - number_integer | -2147483648..-32769 | Negative integer (4 bytes follow) | 0x3a - number_integer | -32768..-129 | Negative integer (2 bytes follow) | 0x39 - number_integer | -128..-25 | Negative integer (1 byte follow) | 0x38 - number_integer | -24..-1 | Negative integer | 0x20..0x37 - number_integer | 0..23 | Integer | 0x00..0x17 - number_integer | 24..255 | Unsigned integer (1 byte follow) | 0x18 - number_integer | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 - number_integer | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1a - number_integer | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1b - number_unsigned | 0..23 | Integer | 0x00..0x17 - number_unsigned | 24..255 | Unsigned integer (1 byte follow) | 0x18 - number_unsigned | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 - number_unsigned | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1a - number_unsigned | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1b - number_float | *any value* | Double-Precision Float | 0xfb - string | *length*: 0..23 | UTF-8 string | 0x60..0x77 - string | *length*: 23..255 | UTF-8 string (1 byte follow) | 0x78 - string | *length*: 256..65535 | UTF-8 string (2 bytes follow) | 0x79 - string | *length*: 65536..4294967295 | UTF-8 string (4 bytes follow) | 0x7a - string | *length*: 4294967296..18446744073709551615 | UTF-8 string (8 bytes follow) | 0x7b - array | *size*: 0..23 | array | 0x80..0x97 - array | *size*: 23..255 | array (1 byte follow) | 0x98 - array | *size*: 256..65535 | array (2 bytes follow) | 0x99 - array | *size*: 65536..4294967295 | array (4 bytes follow) | 0x9a - array | *size*: 4294967296..18446744073709551615 | array (8 bytes follow) | 0x9b - object | *size*: 0..23 | map | 0xa0..0xb7 - object | *size*: 23..255 | map (1 byte follow) | 0xb8 - object | *size*: 256..65535 | map (2 bytes follow) | 0xb9 - object | *size*: 65536..4294967295 | map (4 bytes follow) | 0xba - object | *size*: 4294967296..18446744073709551615 | map (8 bytes follow) | 0xbb + @throw type_error.311 when called on a type other than JSON array or + null; example: `"cannot use emplace_back() with number"` + + @complexity Amortized constant. + + @liveexample{The example shows how `push_back()` can be used to add + elements to a JSON array. Note how the `null` value was silently converted + to a JSON array.,emplace_back} + + @since version 2.0.8 + */ + template + void emplace_back(Args&& ... args) + { + // emplace_back only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_array()))) + { + JSON_THROW(type_error::create(311, "cannot use emplace_back() with " + std::string(type_name()))); + } + + // transform null object into an array + if (is_null()) + { + m_type = value_t::array; + m_value = value_t::array; + assert_invariant(); + } - @note The mapping is **complete** in the sense that any JSON value type - can be converted to a CBOR value. + // add element to array (perfect forwarding) + m_value.array->emplace_back(std::forward(args)...); + } - @note The following CBOR types are not used in the conversion: - - byte strings (0x40..0x5f) - - UTF-8 strings terminated by "break" (0x7f) - - arrays terminated by "break" (0x9f) - - maps terminated by "break" (0xbf) - - date/time (0xc0..0xc1) - - bignum (0xc2..0xc3) - - decimal fraction (0xc4) - - bigfloat (0xc5) - - tagged items (0xc6..0xd4, 0xd8..0xdb) - - expected conversions (0xd5..0xd7) - - simple values (0xe0..0xf3, 0xf8) - - undefined (0xf7) - - half and single-precision floats (0xf9-0xfa) - - break (0xff) + /*! + @brief add an object to an object if key does not exist - @param[in] j JSON value to serialize - @return MessagePack serialization as byte vector + Inserts a new element into a JSON object constructed in-place with the + given @a args if there is no element with the key in the container. If the + function is called on a JSON null value, an empty object is created before + appending the value created from @a args. - @complexity Linear in the size of the JSON value @a j. + @param[in] args arguments to forward to a constructor of @ref basic_json + @tparam Args compatible types to create a @ref basic_json object - @liveexample{The example shows the serialization of a JSON value to a byte - vector in CBOR format.,to_cbor} + @return a pair consisting of an iterator to the inserted element, or the + already-existing element if no insertion happened, and a bool + denoting whether the insertion took place. - @sa http://cbor.io - @sa @ref from_cbor(const std::vector&, const size_t) for the - analogous deserialization - @sa @ref to_msgpack(const basic_json& for the related MessagePack format + @throw type_error.311 when called on a type other than JSON object or + null; example: `"cannot use emplace() with number"` - @since version 2.0.9 + @complexity Logarithmic in the size of the container, O(log(`size()`)). + + @liveexample{The example shows how `emplace()` can be used to add elements + to a JSON object. Note how the `null` value was silently converted to a + JSON object. Further note how no value is added if there was already one + value stored with the same key.,emplace} + + @since version 2.0.8 */ - static std::vector to_cbor(const basic_json& j) + template + std::pair emplace(Args&& ... args) { - std::vector result; - binary_writer bw(output_adapter::create(result)); - bw.write_cbor(j); - return result; - } + // emplace only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_object()))) + { + JSON_THROW(type_error::create(311, "cannot use emplace() with " + std::string(type_name()))); + } - /*! - @brief create a MessagePack serialization of a given JSON value + // transform null object into an object + if (is_null()) + { + m_type = value_t::object; + m_value = value_t::object; + assert_invariant(); + } - Serializes a given JSON value @a j to a byte vector using the MessagePack - serialization format. MessagePack is a binary serialization format which - aims to be more compact than JSON itself, yet more efficient to parse. + // add element to array (perfect forwarding) + auto res = m_value.object->emplace(std::forward(args)...); + // create result iterator and set iterator to the result of emplace + auto it = begin(); + it.m_it.object_iterator = res.first; - The library uses the following mapping from JSON values types to - MessagePack types according to the MessagePack specification: + // return pair of iterator and boolean + return {it, res.second}; + } - JSON value type | value/range | MessagePack type | first byte - --------------- | --------------------------------- | ---------------- | ---------- - null | `null` | nil | 0xc0 - boolean | `true` | true | 0xc3 - boolean | `false` | false | 0xc2 - number_integer | -9223372036854775808..-2147483649 | int64 | 0xd3 - number_integer | -2147483648..-32769 | int32 | 0xd2 - number_integer | -32768..-129 | int16 | 0xd1 - number_integer | -128..-33 | int8 | 0xd0 - number_integer | -32..-1 | negative fixint | 0xe0..0xff - number_integer | 0..127 | positive fixint | 0x00..0x7f - number_integer | 128..255 | uint 8 | 0xcc - number_integer | 256..65535 | uint 16 | 0xcd - number_integer | 65536..4294967295 | uint 32 | 0xce - number_integer | 4294967296..18446744073709551615 | uint 64 | 0xcf - number_unsigned | 0..127 | positive fixint | 0x00..0x7f - number_unsigned | 128..255 | uint 8 | 0xcc - number_unsigned | 256..65535 | uint 16 | 0xcd - number_unsigned | 65536..4294967295 | uint 32 | 0xce - number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xcf - number_float | *any value* | float 64 | 0xcb - string | *length*: 0..31 | fixstr | 0xa0..0xbf - string | *length*: 32..255 | str 8 | 0xd9 - string | *length*: 256..65535 | str 16 | 0xda - string | *length*: 65536..4294967295 | str 32 | 0xdb - array | *size*: 0..15 | fixarray | 0x90..0x9f - array | *size*: 16..65535 | array 16 | 0xdc - array | *size*: 65536..4294967295 | array 32 | 0xdd - object | *size*: 0..15 | fix map | 0x80..0x8f - object | *size*: 16..65535 | map 16 | 0xde - object | *size*: 65536..4294967295 | map 32 | 0xdf + /*! + @brief inserts element - @note The mapping is **complete** in the sense that any JSON value type - can be converted to a MessagePack value. + Inserts element @a val before iterator @a pos. - @note The following values can **not** be converted to a MessagePack value: - - strings with more than 4294967295 bytes - - arrays with more than 4294967295 elements - - objects with more than 4294967295 elements + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] val element to insert + @return iterator pointing to the inserted @a val. - @note The following MessagePack types are not used in the conversion: - - bin 8 - bin 32 (0xc4..0xc6) - - ext 8 - ext 32 (0xc7..0xc9) - - float 32 (0xca) - - fixext 1 - fixext 16 (0xd4..0xd8) + @throw type_error.309 if called on JSON values other than arrays; + example: `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` - @note Any MessagePack output created @ref to_msgpack can be successfully - parsed by @ref from_msgpack. + @complexity Constant plus linear in the distance between @a pos and end of + the container. - @param[in] j JSON value to serialize - @return MessagePack serialization as byte vector + @liveexample{The example shows how `insert()` is used.,insert} - @complexity Linear in the size of the JSON value @a j. + @since version 1.0.0 + */ + iterator insert(const_iterator pos, const basic_json& val) + { + // insert only works for arrays + if (JSON_LIKELY(is_array())) + { + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - @liveexample{The example shows the serialization of a JSON value to a byte - vector in MessagePack format.,to_msgpack} + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, val); + return result; + } - @sa http://msgpack.org - @sa @ref from_msgpack(const std::vector&, const size_t) for the - analogous deserialization - @sa @ref to_cbor(const basic_json& for the related CBOR format + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - @since version 2.0.9 + /*! + @brief inserts element + @copydoc insert(const_iterator, const basic_json&) */ - static std::vector to_msgpack(const basic_json& j) + iterator insert(const_iterator pos, basic_json&& val) { - std::vector result; - binary_writer bw(output_adapter::create(result)); - bw.write_msgpack(j); - return result; + return insert(pos, val); } /*! - @brief create a JSON value from a byte vector in CBOR format + @brief inserts elements - Deserializes a given byte vector @a v to a JSON value using the CBOR - (Concise Binary Object Representation) serialization format. + Inserts @a cnt copies of @a val before iterator @a pos. - The library maps CBOR types to JSON value types as follows: + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] cnt number of copies of @a val to insert + @param[in] val element to insert + @return iterator pointing to the first element inserted, or @a pos if + `cnt==0` - CBOR type | JSON value type | first byte - ---------------------- | --------------- | ---------- - Integer | number_unsigned | 0x00..0x17 - Unsigned integer | number_unsigned | 0x18 - Unsigned integer | number_unsigned | 0x19 - Unsigned integer | number_unsigned | 0x1a - Unsigned integer | number_unsigned | 0x1b - Negative integer | number_integer | 0x20..0x37 - Negative integer | number_integer | 0x38 - Negative integer | number_integer | 0x39 - Negative integer | number_integer | 0x3a - Negative integer | number_integer | 0x3b - Negative integer | number_integer | 0x40..0x57 - UTF-8 string | string | 0x60..0x77 - UTF-8 string | string | 0x78 - UTF-8 string | string | 0x79 - UTF-8 string | string | 0x7a - UTF-8 string | string | 0x7b - UTF-8 string | string | 0x7f - array | array | 0x80..0x97 - array | array | 0x98 - array | array | 0x99 - array | array | 0x9a - array | array | 0x9b - array | array | 0x9f - map | object | 0xa0..0xb7 - map | object | 0xb8 - map | object | 0xb9 - map | object | 0xba - map | object | 0xbb - map | object | 0xbf - False | `false` | 0xf4 - True | `true` | 0xf5 - Nill | `null` | 0xf6 - Half-Precision Float | number_float | 0xf9 - Single-Precision Float | number_float | 0xfa - Double-Precision Float | number_float | 0xfb + @throw type_error.309 if called on JSON values other than arrays; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` - @warning The mapping is **incomplete** in the sense that not all CBOR - types can be converted to a JSON value. The following CBOR types - are not supported and will yield parse errors (parse_error.112): - - byte strings (0x40..0x5f) - - date/time (0xc0..0xc1) - - bignum (0xc2..0xc3) - - decimal fraction (0xc4) - - bigfloat (0xc5) - - tagged items (0xc6..0xd4, 0xd8..0xdb) - - expected conversions (0xd5..0xd7) - - simple values (0xe0..0xf3, 0xf8) - - undefined (0xf7) + @complexity Linear in @a cnt plus linear in the distance between @a pos + and end of the container. - @warning CBOR allows map keys of any type, whereas JSON only allows - strings as keys in object values. Therefore, CBOR maps with keys - other than UTF-8 strings are rejected (parse_error.113). + @liveexample{The example shows how `insert()` is used.,insert__count} - @note Any CBOR output created @ref to_cbor can be successfully parsed by - @ref from_cbor. + @since version 1.0.0 + */ + iterator insert(const_iterator pos, size_type cnt, const basic_json& val) + { + // insert only works for arrays + if (JSON_LIKELY(is_array())) + { + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - @param[in] v a byte vector in CBOR format - @param[in] start_index the index to start reading from @a v (0 by default) - @return deserialized JSON value + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val); + return result; + } - @throw parse_error.110 if the given vector ends prematurely - @throw parse_error.112 if unsupported features from CBOR were - used in the given vector @a v or if the input is not valid CBOR - @throw parse_error.113 if a string was expected as map key, but not found + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - @complexity Linear in the size of the byte vector @a v. + /*! + @brief inserts elements - @liveexample{The example shows the deserialization of a byte vector in CBOR - format to a JSON value.,from_cbor} + Inserts elements from range `[first, last)` before iterator @a pos. - @sa http://cbor.io - @sa @ref to_cbor(const basic_json&) for the analogous serialization - @sa @ref from_msgpack(const std::vector&, const size_t) for the - related MessagePack format + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] first begin of the range of elements to insert + @param[in] last end of the range of elements to insert + + @throw type_error.309 if called on JSON values other than arrays; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` + @throw invalid_iterator.210 if @a first and @a last do not belong to the + same JSON value; example: `"iterators do not fit"` + @throw invalid_iterator.211 if @a first or @a last are iterators into + container for which insert is called; example: `"passed iterators may not + belong to container"` + + @return iterator pointing to the first element inserted, or @a pos if + `first==last` + + @complexity Linear in `std::distance(first, last)` plus linear in the + distance between @a pos and end of the container. - @since version 2.0.9, parameter @a start_index since 2.1.1 + @liveexample{The example shows how `insert()` is used.,insert__range} + + @since version 1.0.0 */ - static basic_json from_cbor(const std::vector& v, - const size_t start_index = 0) + iterator insert(const_iterator pos, const_iterator first, const_iterator last) { - binary_reader br(input_adapter::create(v.begin() + static_cast(start_index), v.end())); - return br.parse_cbor(); - } - + // insert only works for arrays + if (JSON_UNLIKELY(not is_array())) + { + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - /*! - @brief create a JSON value from a byte vector in MessagePack format + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - Deserializes a given byte vector @a v to a JSON value using the MessagePack - serialization format. + // check if range iterators belong to the same JSON object + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + } - The library maps MessagePack types to JSON value types as follows: + if (JSON_UNLIKELY(first.m_object == this)) + { + JSON_THROW(invalid_iterator::create(211, "passed iterators may not belong to container")); + } - MessagePack type | JSON value type | first byte - ---------------- | --------------- | ---------- - positive fixint | number_unsigned | 0x00..0x7f - fixmap | object | 0x80..0x8f - fixarray | array | 0x90..0x9f - fixstr | string | 0xa0..0xbf - nil | `null` | 0xc0 - false | `false` | 0xc2 - true | `true` | 0xc3 - float 32 | number_float | 0xca - float 64 | number_float | 0xcb - uint 8 | number_unsigned | 0xcc - uint 16 | number_unsigned | 0xcd - uint 32 | number_unsigned | 0xce - uint 64 | number_unsigned | 0xcf - int 8 | number_integer | 0xd0 - int 16 | number_integer | 0xd1 - int 32 | number_integer | 0xd2 - int 64 | number_integer | 0xd3 - str 8 | string | 0xd9 - str 16 | string | 0xda - str 32 | string | 0xdb - array 16 | array | 0xdc - array 32 | array | 0xdd - map 16 | object | 0xde - map 32 | object | 0xdf - negative fixint | number_integer | 0xe0-0xff + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert( + pos.m_it.array_iterator, + first.m_it.array_iterator, + last.m_it.array_iterator); + return result; + } - @warning The mapping is **incomplete** in the sense that not all - MessagePack types can be converted to a JSON value. The following - MessagePack types are not supported and will yield parse errors: - - bin 8 - bin 32 (0xc4..0xc6) - - ext 8 - ext 32 (0xc7..0xc9) - - fixext 1 - fixext 16 (0xd4..0xd8) + /*! + @brief inserts elements - @note Any MessagePack output created @ref to_msgpack can be successfully - parsed by @ref from_msgpack. + Inserts elements from initializer list @a ilist before iterator @a pos. - @param[in] v a byte vector in MessagePack format - @param[in] start_index the index to start reading from @a v (0 by default) - @return deserialized JSON value + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] ilist initializer list to insert the values from - @throw parse_error.110 if the given vector ends prematurely - @throw parse_error.112 if unsupported features from MessagePack were - used in the given vector @a v or if the input is not valid MessagePack - @throw parse_error.113 if a string was expected as map key, but not found + @throw type_error.309 if called on JSON values other than arrays; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` - @complexity Linear in the size of the byte vector @a v. + @return iterator pointing to the first element inserted, or @a pos if + `ilist` is empty - @liveexample{The example shows the deserialization of a byte vector in - MessagePack format to a JSON value.,from_msgpack} + @complexity Linear in `ilist.size()` plus linear in the distance between + @a pos and end of the container. - @sa http://msgpack.org - @sa @ref to_msgpack(const basic_json&) for the analogous serialization - @sa @ref from_cbor(const std::vector&, const size_t) for the - related CBOR format + @liveexample{The example shows how `insert()` is used.,insert__ilist} - @since version 2.0.9, parameter @a start_index since 2.1.1 + @since version 1.0.0 */ - static basic_json from_msgpack(const std::vector& v, - const size_t start_index = 0) + iterator insert(const_iterator pos, initializer_list_t ilist) { - binary_reader br(input_adapter::create(v.begin() + static_cast(start_index), v.end())); - return br.parse_msgpack(); - } + // insert only works for arrays + if (JSON_UNLIKELY(not is_array())) + { + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - /// @} + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - ////////////////////// - // lexer and parser // - ////////////////////// + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist.begin(), ilist.end()); + return result; + } - private: /*! - @brief lexical analysis + @brief inserts elements + + Inserts elements from range `[first, last)`. + + @param[in] first begin of the range of elements to insert + @param[in] last end of the range of elements to insert + + @throw type_error.309 if called on JSON values other than objects; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if iterator @a first or @a last does does not + point to an object; example: `"iterators first and last must point to + objects"` + @throw invalid_iterator.210 if @a first and @a last do not belong to the + same JSON value; example: `"iterators do not fit"` + + @complexity Logarithmic: `O(N*log(size() + N))`, where `N` is the number + of elements to insert. + + @liveexample{The example shows how `insert()` is used.,insert__range_object} - This class organizes the lexical analysis during JSON deserialization. + @since version 3.0.0 */ - class lexer + void insert(const_iterator first, const_iterator last) { - public: - /// token types for the parser - enum class token_type - { - uninitialized, ///< indicating the scanner is uninitialized - literal_true, ///< the `true` literal - literal_false, ///< the `false` literal - literal_null, ///< the `null` literal - value_string, ///< a string -- use get_string() for actual value - value_unsigned, ///< an unsigned integer -- use get_number_unsigned() for actual value - value_integer, ///< a signed integer -- use get_number_integer() for actual value - value_float, ///< an floating point number -- use get_number_float() for actual value - begin_array, ///< the character for array begin `[` - begin_object, ///< the character for object begin `{` - end_array, ///< the character for array end `]` - end_object, ///< the character for object end `}` - name_separator, ///< the name separator `:` - value_separator, ///< the value separator `,` - parse_error, ///< indicating a parse error - end_of_input ///< indicating the end of the input buffer - }; - - /// return name of values of type token_type (only used for errors) - static const char* token_type_name(const token_type t) noexcept + // insert only works for objects + if (JSON_UNLIKELY(not is_object())) { - switch (t) - { - case token_type::uninitialized: - return ""; - case token_type::literal_true: - return "true literal"; - case token_type::literal_false: - return "false literal"; - case token_type::literal_null: - return "null literal"; - case token_type::value_string: - return "string literal"; - case lexer::token_type::value_unsigned: - case lexer::token_type::value_integer: - case lexer::token_type::value_float: - return "number literal"; - case token_type::begin_array: - return "'['"; - case token_type::begin_object: - return "'{'"; - case token_type::end_array: - return "']'"; - case token_type::end_object: - return "'}'"; - case token_type::name_separator: - return "':'"; - case token_type::value_separator: - return "','"; - case token_type::parse_error: - return ""; - case token_type::end_of_input: - return "end of input"; - default: - { - // catch non-enum values - return "unknown token"; // LCOV_EXCL_LINE - } - } + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); } - explicit lexer(input_adapter_t adapter) - : ia(adapter), decimal_point_char(get_decimal_point()) - {} - - private: - ///////////////////// - // locales - ///////////////////// + // check if range iterators belong to the same JSON object + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + } - /// return the locale-dependent decimal point - static char get_decimal_point() noexcept + // passed iterators must belong to objects + if (JSON_UNLIKELY(not first.m_object->is_object())) { - const auto loc = localeconv(); - assert(loc != nullptr); - return (loc->decimal_point == nullptr) ? '.' : loc->decimal_point[0]; + JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects")); } - ///////////////////// - // scan functions - ///////////////////// + m_value.object->insert(first.m_it.object_iterator, last.m_it.object_iterator); + } - /*! - @brief get codepoint from 4 hex characters following `\u` + /*! + @brief updates a JSON object from another object, overwriting existing keys - @return codepoint or -1 in case of an error (e.g. EOF or non-hex - character) - */ - int get_codepoint() - { - // this function only makes sense after reading `\u` - assert(current == 'u'); - int codepoint = 0; + Inserts all values from JSON object @a j and overwrites existing keys. - // byte 1: \uXxxx - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x1000; - break; - case '2': - codepoint += 0x2000; - break; - case '3': - codepoint += 0x3000; - break; - case '4': - codepoint += 0x4000; - break; - case '5': - codepoint += 0x5000; - break; - case '6': - codepoint += 0x6000; - break; - case '7': - codepoint += 0x7000; - break; - case '8': - codepoint += 0x8000; - break; - case '9': - codepoint += 0x9000; - break; - case 'A': - case 'a': - codepoint += 0xa000; - break; - case 'B': - case 'b': - codepoint += 0xb000; - break; - case 'C': - case 'c': - codepoint += 0xc000; - break; - case 'D': - case 'd': - codepoint += 0xd000; - break; - case 'E': - case 'e': - codepoint += 0xe000; - break; - case 'F': - case 'f': - codepoint += 0xf000; - break; - default: - return -1; - } + @param[in] j JSON object to read values from - // byte 2: \uxXxx - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x0100; - break; - case '2': - codepoint += 0x0200; - break; - case '3': - codepoint += 0x0300; - break; - case '4': - codepoint += 0x0400; - break; - case '5': - codepoint += 0x0500; - break; - case '6': - codepoint += 0x0600; - break; - case '7': - codepoint += 0x0700; - break; - case '8': - codepoint += 0x0800; - break; - case '9': - codepoint += 0x0900; - break; - case 'A': - case 'a': - codepoint += 0x0a00; - break; - case 'B': - case 'b': - codepoint += 0x0b00; - break; - case 'C': - case 'c': - codepoint += 0x0c00; - break; - case 'D': - case 'd': - codepoint += 0x0d00; - break; - case 'E': - case 'e': - codepoint += 0x0e00; - break; - case 'F': - case 'f': - codepoint += 0x0f00; - break; - default: - return -1; - } + @throw type_error.312 if called on JSON values other than objects; example: + `"cannot use update() with string"` - // byte 3: \uxxXx - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x0010; - break; - case '2': - codepoint += 0x0020; - break; - case '3': - codepoint += 0x0030; - break; - case '4': - codepoint += 0x0040; - break; - case '5': - codepoint += 0x0050; - break; - case '6': - codepoint += 0x0060; - break; - case '7': - codepoint += 0x0070; - break; - case '8': - codepoint += 0x0080; - break; - case '9': - codepoint += 0x0090; - break; - case 'A': - case 'a': - codepoint += 0x00a0; - break; - case 'B': - case 'b': - codepoint += 0x00b0; - break; - case 'C': - case 'c': - codepoint += 0x00c0; - break; - case 'D': - case 'd': - codepoint += 0x00d0; - break; - case 'E': - case 'e': - codepoint += 0x00e0; - break; - case 'F': - case 'f': - codepoint += 0x00f0; - break; - default: - return -1; - } + @complexity O(N*log(size() + N)), where N is the number of elements to + insert. - // byte 4: \uxxxX - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x0001; - break; - case '2': - codepoint += 0x0002; - break; - case '3': - codepoint += 0x0003; - break; - case '4': - codepoint += 0x0004; - break; - case '5': - codepoint += 0x0005; - break; - case '6': - codepoint += 0x0006; - break; - case '7': - codepoint += 0x0007; - break; - case '8': - codepoint += 0x0008; - break; - case '9': - codepoint += 0x0009; - break; - case 'A': - case 'a': - codepoint += 0x000a; - break; - case 'B': - case 'b': - codepoint += 0x000b; - break; - case 'C': - case 'c': - codepoint += 0x000c; - break; - case 'D': - case 'd': - codepoint += 0x000d; - break; - case 'E': - case 'e': - codepoint += 0x000e; - break; - case 'F': - case 'f': - codepoint += 0x000f; - break; - default: - return -1; - } + @liveexample{The example shows how `update()` is used.,update} - return codepoint; - } + @sa https://docs.python.org/3.6/library/stdtypes.html#dict.update - /*! - @brief create diagnostic representation of a codepoint - @return string "U+XXXX" for codepoint XXXX - */ - static std::string codepoint_to_string(int codepoint) + @since version 3.0.0 + */ + void update(const_reference j) + { + // implicitly convert null value to an empty object + if (is_null()) { - std::stringstream ss; - ss << "U+" << std::setw(4) << std::uppercase << std::setfill('0') << std::hex << codepoint; - return ss.str(); + m_type = value_t::object; + m_value.object = create(); + assert_invariant(); } - /*! - @brief scan a string literal + if (JSON_UNLIKELY(not is_object())) + { + JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(type_name()))); + } + if (JSON_UNLIKELY(not j.is_object())) + { + JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(j.type_name()))); + } - This function scans a string according to Sect. 7 of RFC 7159. While - scanning, bytes are escaped and copied into buffer yytext. Then the - function returns successfully, yytext is null-terminated and yylen - contains the number of bytes in the string. + for (auto it = j.cbegin(); it != j.cend(); ++it) + { + m_value.object->operator[](it.key()) = it.value(); + } + } - @return token_type::value_string if string could be successfully - scanned, token_type::parse_error otherwise + /*! + @brief updates a JSON object from another object, overwriting existing keys - @note In case of errors, variable error_message contains a textual - description. - */ - token_type scan_string() - { - // reset yytext (ignore opening quote) - reset(); + Inserts all values from from range `[first, last)` and overwrites existing + keys. - // we entered the function by reading an open quote - assert(current == '\"'); + @param[in] first begin of the range of elements to insert + @param[in] last end of the range of elements to insert - while (true) - { - // get next character - get(); + @throw type_error.312 if called on JSON values other than objects; example: + `"cannot use update() with string"` + @throw invalid_iterator.202 if iterator @a first or @a last does does not + point to an object; example: `"iterators first and last must point to + objects"` + @throw invalid_iterator.210 if @a first and @a last do not belong to the + same JSON value; example: `"iterators do not fit"` - switch (current) - { - // end of file while parsing string - case std::char_traits::eof(): - { - error_message = "invalid string: missing closing quote"; - return token_type::parse_error; - } + @complexity O(N*log(size() + N)), where N is the number of elements to + insert. - // closing quote - case '\"': - { - // terminate yytext - add('\0'); - --yylen; - return token_type::value_string; - } + @liveexample{The example shows how `update()` is used__range.,update} - // escapes - case '\\': - { - switch (get()) - { - // quotation mark - case '\"': - add('\"'); - break; - // reverse solidus - case '\\': - add('\\'); - break; - // solidus - case '/': - add('/'); - break; - // backspace - case 'b': - add('\b'); - break; - // form feed - case 'f': - add('\f'); - break; - // line feed - case 'n': - add('\n'); - break; - // carriage return - case 'r': - add('\r'); - break; - // tab - case 't': - add('\t'); - break; - - // unicode escapes - case 'u': - { - int codepoint; - int codepoint1 = get_codepoint(); + @sa https://docs.python.org/3.6/library/stdtypes.html#dict.update - if (JSON_UNLIKELY(codepoint1 == -1)) - { - error_message = "invalid string: '\\u' must be followed by 4 hex digits"; - return token_type::parse_error; - } + @since version 3.0.0 + */ + void update(const_iterator first, const_iterator last) + { + // implicitly convert null value to an empty object + if (is_null()) + { + m_type = value_t::object; + m_value.object = create(); + assert_invariant(); + } - // check if code point is a high surrogate - if (0xD800 <= codepoint1 and codepoint1 <= 0xDBFF) - { - // expect next \uxxxx entry - if (JSON_LIKELY(get() == '\\' and get() == 'u')) - { - const int codepoint2 = get_codepoint(); - - if (JSON_UNLIKELY(codepoint2 == -1)) - { - error_message = "invalid string: '\\u' must be followed by 4 hex digits"; - return token_type::parse_error; - } - - // check if codepoint2 is a low surrogate - if (JSON_LIKELY(0xDC00 <= codepoint2 and codepoint2 <= 0xDFFF)) - { - codepoint = - // high surrogate occupies the most significant 22 bits - (codepoint1 << 10) - // low surrogate occupies the least significant 15 bits - + codepoint2 - // there is still the 0xD800, 0xDC00 and 0x10000 noise - // in the result so we have to subtract with: - // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00 - - 0x35FDC00; - } - else - { - error_message = "invalid string: surrogate " + codepoint_to_string(codepoint1) + " must be followed by U+DC00..U+DFFF instead of " + codepoint_to_string(codepoint2); - return token_type::parse_error; - } - } - else - { - error_message = "invalid string: surrogate " + codepoint_to_string(codepoint1) + " must be followed by U+DC00..U+DFFF"; - return token_type::parse_error; - } - } - else - { - if (JSON_UNLIKELY(0xDC00 <= codepoint1 and codepoint1 <= 0xDFFF)) - { - error_message = "invalid string: surrogate " + codepoint_to_string(codepoint1) + " must follow U+D800..U+DBFF"; - return token_type::parse_error; - } + if (JSON_UNLIKELY(not is_object())) + { + JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(type_name()))); + } - // only work with first code point - codepoint = codepoint1; - } + // check if range iterators belong to the same JSON object + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + } - // result of the above calculation yields a proper codepoint - assert(0x00 <= codepoint and codepoint <= 0x10FFFF); + // passed iterators must belong to objects + if (JSON_UNLIKELY(not first.m_object->is_object() + or not last.m_object->is_object())) + { + JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects")); + } - // translate code point to bytes - if (codepoint < 0x80) - { - // 1-byte characters: 0xxxxxxx (ASCII) - add(codepoint); - } - else if (codepoint <= 0x7ff) - { - // 2-byte characters: 110xxxxx 10xxxxxx - add(0xC0 | (codepoint >> 6)); - add(0x80 | (codepoint & 0x3F)); - } - else if (codepoint <= 0xffff) - { - // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx - add(0xE0 | (codepoint >> 12)); - add(0x80 | ((codepoint >> 6) & 0x3F)); - add(0x80 | (codepoint & 0x3F)); - } - else - { - // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx - add(0xF0 | (codepoint >> 18)); - add(0x80 | ((codepoint >> 12) & 0x3F)); - add(0x80 | ((codepoint >> 6) & 0x3F)); - add(0x80 | (codepoint & 0x3F)); - } + for (auto it = first; it != last; ++it) + { + m_value.object->operator[](it.key()) = it.value(); + } + } - break; - } + /*! + @brief exchanges the values - // other characters after escape - default: - error_message = "invalid string: forbidden character after backslash"; - return token_type::parse_error; - } + Exchanges the contents of the JSON value with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. - break; - } + @param[in,out] other JSON value to exchange the contents with - // invalid control characters - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - error_message = "invalid string: control character " + codepoint_to_string(current) + " must be escaped"; - return token_type::parse_error; - } + @complexity Constant. - // U+0020..U+007F (except U+0022 (quote) and U+005C (backspace)) - case 0x20: - case 0x21: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - case 0x38: - case 0x39: - case 0x3a: - case 0x3b: - case 0x3c: - case 0x3d: - case 0x3e: - case 0x3f: - case 0x40: - case 0x41: - case 0x42: - case 0x43: - case 0x44: - case 0x45: - case 0x46: - case 0x47: - case 0x48: - case 0x49: - case 0x4a: - case 0x4b: - case 0x4c: - case 0x4d: - case 0x4e: - case 0x4f: - case 0x50: - case 0x51: - case 0x52: - case 0x53: - case 0x54: - case 0x55: - case 0x56: - case 0x57: - case 0x58: - case 0x59: - case 0x5a: - case 0x5b: - case 0x5d: - case 0x5e: - case 0x5f: - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - case 0x78: - case 0x79: - case 0x7a: - case 0x7b: - case 0x7c: - case 0x7d: - case 0x7e: - case 0x7f: - { - add(current); - break; - } + @liveexample{The example below shows how JSON values can be swapped with + `swap()`.,swap__reference} - // U+0080..U+07FF: bytes C2..DF 80..BF - case 0xc2: - case 0xc3: - case 0xc4: - case 0xc5: - case 0xc6: - case 0xc7: - case 0xc8: - case 0xc9: - case 0xca: - case 0xcb: - case 0xcc: - case 0xcd: - case 0xce: - case 0xcf: - case 0xd0: - case 0xd1: - case 0xd2: - case 0xd3: - case 0xd4: - case 0xd5: - case 0xd6: - case 0xd7: - case 0xd8: - case 0xd9: - case 0xda: - case 0xdb: - case 0xdc: - case 0xdd: - case 0xde: - case 0xdf: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } + @since version 1.0.0 + */ + void swap(reference other) noexcept ( + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value and + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value + ) + { + std::swap(m_type, other.m_type); + std::swap(m_value, other.m_value); + assert_invariant(); + } - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + /*! + @brief exchanges the values - // U+0800..U+0FFF: bytes E0 A0..BF 80..BF - case 0xe0: - { - add(current); - get(); - if (JSON_LIKELY(0xa0 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } + Exchanges the contents of a JSON array with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @param[in,out] other array to exchange the contents with - // U+1000..U+CFFF: bytes E1..EC 80..BF 80..BF - // U+E000..U+FFFF: bytes EE..EF 80..BF 80..BF - case 0xe1: - case 0xe2: - case 0xe3: - case 0xe4: - case 0xe5: - case 0xe6: - case 0xe7: - case 0xe8: - case 0xe9: - case 0xea: - case 0xeb: - case 0xec: - case 0xee: - case 0xef: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } + @throw type_error.310 when JSON value is not an array; example: `"cannot + use swap() with string"` - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @complexity Constant. - // U+D000..U+D7FF: bytes ED 80..9F 80..BF - case 0xed: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0x9f)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } + @liveexample{The example below shows how arrays can be swapped with + `swap()`.,swap__array_t} - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @since version 1.0.0 + */ + void swap(array_t& other) + { + // swap only works for arrays + if (JSON_LIKELY(is_array())) + { + std::swap(*(m_value.array), other); + } + else + { + JSON_THROW(type_error::create(310, "cannot use swap() with " + std::string(type_name()))); + } + } - // U+10000..U+3FFFF F0 90..BF 80..BF 80..BF - case 0xf0: - { - add(current); - get(); - if (JSON_LIKELY(0x90 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } - } + /*! + @brief exchanges the values - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + Exchanges the contents of a JSON object with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. - // U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF - case 0xf1: - case 0xf2: - case 0xf3: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } - } + @param[in,out] other object to exchange the contents with - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @throw type_error.310 when JSON value is not an object; example: + `"cannot use swap() with string"` - // U+100000..U+10FFFF F4 80..8F 80..BF 80..BF - case 0xf4: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0x8f)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } - } + @complexity Constant. - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @liveexample{The example below shows how objects can be swapped with + `swap()`.,swap__object_t} - // remaining bytes (80..C1 and F5..FF) are ill-formed - default: - { - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } - } - } + @since version 1.0.0 + */ + void swap(object_t& other) + { + // swap only works for objects + if (JSON_LIKELY(is_object())) + { + std::swap(*(m_value.object), other); } - - static void strtof(float& f, const char* str, char** endptr) noexcept + else { - f = std::strtof(str, endptr); + JSON_THROW(type_error::create(310, "cannot use swap() with " + std::string(type_name()))); } + } + + /*! + @brief exchanges the values + + Exchanges the contents of a JSON string with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. + + @param[in,out] other string to exchange the contents with + + @throw type_error.310 when JSON value is not a string; example: `"cannot + use swap() with boolean"` - static void strtof(double& f, const char* str, char** endptr) noexcept + @complexity Constant. + + @liveexample{The example below shows how strings can be swapped with + `swap()`.,swap__string_t} + + @since version 1.0.0 + */ + void swap(string_t& other) + { + // swap only works for strings + if (JSON_LIKELY(is_string())) { - f = std::strtod(str, endptr); + std::swap(*(m_value.string), other); } - - static void strtof(long double& f, const char* str, char** endptr) noexcept + else { - f = std::strtold(str, endptr); + JSON_THROW(type_error::create(310, "cannot use swap() with " + std::string(type_name()))); } + } + + /// @} - /*! - @brief scan a number literal + public: + ////////////////////////////////////////// + // lexicographical comparison operators // + ////////////////////////////////////////// + + /// @name lexicographical comparison operators + /// @{ + + /*! + @brief comparison: equal - This function scans a string according to Sect. 6 of RFC 7159. + Compares two JSON values for equality according to the following rules: + - Two JSON values are equal if (1) they are from the same type and (2) + their stored values are the same according to their respective + `operator==`. + - Integer and floating-point numbers are automatically converted before + comparison. Note than two NaN values are always treated as unequal. + - Two JSON null values are equal. - The function is realized with a deterministic finite state machine - derived from the grammar described in RFC 7159. Starting in state - "init", the input is read and used to determined the next state. Only - state "done" accepts the number. State "error" is a trap state to model - errors. In the table below, "anything" means any character but the ones - listed before. + @note Floating-point inside JSON values numbers are compared with + `json::number_float_t::operator==` which is `double::operator==` by + default. To compare floating-point while respecting an epsilon, an alternative + [comparison function](https://github.com/mariokonrad/marnav/blob/master/src/marnav/math/floatingpoint.hpp#L34-#L39) + could be used, for instance + @code {.cpp} + template::value, T>::type> + inline bool is_same(T a, T b, T epsilon = std::numeric_limits::epsilon()) noexcept + { + return std::abs(a - b) <= epsilon; + } + @endcode - state | 0 | 1-9 | e E | + | - | . | anything - ---------|----------|----------|----------|---------|---------|----------|----------- - init | zero | any1 | [error] | [error] | minus | [error] | [error] - minus | zero | any1 | [error] | [error] | [error] | [error] | [error] - zero | done | done | exponent | done | done | decimal1 | done - any1 | any1 | any1 | exponent | done | done | decimal1 | done - decimal1 | decimal2 | [error] | [error] | [error] | [error] | [error] | [error] - decimal2 | decimal2 | decimal2 | exponent | done | done | done | done - exponent | any2 | any2 | [error] | sign | sign | [error] | [error] - sign | any2 | any2 | [error] | [error] | [error] | [error] | [error] - any2 | any2 | any2 | done | done | done | done | done + @note NaN values never compare equal to themselves or to other NaN values. - The state machine is realized with one label per state (prefixed with - "scan_number_") and `goto` statements between them. The state machine - contains cycles, but any cycle can be left when EOF is read. Therefore, - the function is guaranteed to terminate. + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether the values @a lhs and @a rhs are equal - During scanning, the read bytes are stored in yytext. This string is - then converted to a signed integer, an unsigned integer, or a - floating-point number. + @exceptionsafety No-throw guarantee: this function never throws exceptions. - @return token_type::value_unsigned, token_type::value_integer, or - token_type::value_float if number could be successfully scanned, - token_type::parse_error otherwise + @complexity Linear. - @note The scanner is independent of the current locale. Internally, the - locale's decimal point is used instead of `.` to work with the - locale-dependent converters. - */ - token_type scan_number() - { - // reset yytext to store the number's bytes - reset(); + @liveexample{The example demonstrates comparing several JSON + types.,operator__equal} - // the type of the parsed number; initially set to unsigned; will be - // changed if minus sign, decimal point or exponent is read - token_type number_type = token_type::value_unsigned; + @since version 1.0.0 + */ + friend bool operator==(const_reference lhs, const_reference rhs) noexcept + { + const auto lhs_type = lhs.type(); + const auto rhs_type = rhs.type(); - // state (init): we just found out we need to scan a number - switch (current) + if (lhs_type == rhs_type) + { + switch (lhs_type) { - case '-': - { - add(current); - goto scan_number_minus; - } + case value_t::array: + return (*lhs.m_value.array == *rhs.m_value.array); - case '0': - { - add(current); - goto scan_number_zero; - } + case value_t::object: + return (*lhs.m_value.object == *rhs.m_value.object); - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any1; - } + case value_t::null: + return true; - default: - { - // all other characters are rejected outside scan_number() - assert(false); // LCOV_EXCL_LINE - } - } + case value_t::string: + return (*lhs.m_value.string == *rhs.m_value.string); -scan_number_minus: - // state: we just parsed a leading minus sign - number_type = token_type::value_integer; - switch (get()) - { - case '0': - { - add(current); - goto scan_number_zero; - } + case value_t::boolean: + return (lhs.m_value.boolean == rhs.m_value.boolean); - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any1; - } + case value_t::number_integer: + return (lhs.m_value.number_integer == rhs.m_value.number_integer); + + case value_t::number_unsigned: + return (lhs.m_value.number_unsigned == rhs.m_value.number_unsigned); + + case value_t::number_float: + return (lhs.m_value.number_float == rhs.m_value.number_float); default: - { - error_message = "invalid number; expected digit after '-'"; - return token_type::parse_error; - } + return false; } + } + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) + { + return (static_cast(lhs.m_value.number_integer) == rhs.m_value.number_float); + } + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) + { + return (lhs.m_value.number_float == static_cast(rhs.m_value.number_integer)); + } + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) + { + return (static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_float); + } + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) + { + return (lhs.m_value.number_float == static_cast(rhs.m_value.number_unsigned)); + } + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) + { + return (static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_integer); + } + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) + { + return (lhs.m_value.number_integer == static_cast(rhs.m_value.number_unsigned)); + } + + return false; + } -scan_number_zero: - // state: we just parse a zero (maybe with a leading minus sign) - switch (get()) - { - case '.': - { - add(decimal_point_char); - goto scan_number_decimal1; - } + /*! + @brief comparison: equal + @copydoc operator==(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator==(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs == basic_json(rhs)); + } - case 'e': - case 'E': - { - add(current); - goto scan_number_exponent; - } + /*! + @brief comparison: equal + @copydoc operator==(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator==(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) == rhs); + } - default: - { - goto scan_number_done; - } - } + /*! + @brief comparison: not equal -scan_number_any1: - // state: we just parsed a number 0-9 (maybe with a leading minus sign) - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any1; - } + Compares two JSON values for inequality by calculating `not (lhs == rhs)`. - case '.': - { - add(decimal_point_char); - goto scan_number_decimal1; - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether the values @a lhs and @a rhs are not equal - case 'e': - case 'E': - { - add(current); - goto scan_number_exponent; - } + @complexity Linear. - default: - { - goto scan_number_done; - } - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. -scan_number_decimal1: - // state: we just parsed a decimal point - number_type = token_type::value_float; - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_decimal2; - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__notequal} - default: - { - error_message = "invalid number; expected digit after '.'"; - return token_type::parse_error; - } - } + @since version 1.0.0 + */ + friend bool operator!=(const_reference lhs, const_reference rhs) noexcept + { + return not (lhs == rhs); + } -scan_number_decimal2: - // we just parsed at least one number after a decimal point - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_decimal2; - } + /*! + @brief comparison: not equal + @copydoc operator!=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator!=(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs != basic_json(rhs)); + } - case 'e': - case 'E': - { - add(current); - goto scan_number_exponent; - } + /*! + @brief comparison: not equal + @copydoc operator!=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator!=(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) != rhs); + } - default: - { - goto scan_number_done; - } - } + /*! + @brief comparison: less than -scan_number_exponent: - // we just parsed an exponent - number_type = token_type::value_float; - switch (get()) - { - case '+': - case '-': - { - add(current); - goto scan_number_sign; - } + Compares whether one JSON value @a lhs is less than another JSON value @a + rhs according to the following rules: + - If @a lhs and @a rhs have the same type, the values are compared using + the default `<` operator. + - Integer and floating-point numbers are automatically converted before + comparison + - In case @a lhs and @a rhs have different types, the values are ignored + and the order of the types is considered, see + @ref operator<(const value_t, const value_t). - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any2; - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is less than @a rhs - default: - { - error_message = "invalid number; expected '+', '-', or digit after exponent"; - return token_type::parse_error; - } - } + @complexity Linear. -scan_number_sign: - // we just parsed an exponent sign - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any2; - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - default: - { - error_message = "invalid number; expected digit after exponent sign"; - return token_type::parse_error; - } - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__less} -scan_number_any2: - // we just parsed a number after the exponent or exponent sign - switch (get()) + @since version 1.0.0 + */ + friend bool operator<(const_reference lhs, const_reference rhs) noexcept + { + const auto lhs_type = lhs.type(); + const auto rhs_type = rhs.type(); + + if (lhs_type == rhs_type) + { + switch (lhs_type) { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any2; - } + case value_t::array: + return (*lhs.m_value.array) < (*rhs.m_value.array); - default: - { - goto scan_number_done; - } - } + case value_t::object: + return *lhs.m_value.object < *rhs.m_value.object; -scan_number_done: - // unget the character after the number (we only read it to know - // that we are done scanning a number) - --chars_read; - next_unget = true; + case value_t::null: + return false; - // terminate token - add('\0'); - --yylen; + case value_t::string: + return *lhs.m_value.string < *rhs.m_value.string; - // try to parse integers first and fall back to floats - if (number_type == token_type::value_unsigned) - { - char* endptr = nullptr; - errno = 0; - const auto x = std::strtoull(yytext.data(), &endptr, 10); + case value_t::boolean: + return lhs.m_value.boolean < rhs.m_value.boolean; - // we checked the number format before - assert(endptr == yytext.data() + yylen); + case value_t::number_integer: + return lhs.m_value.number_integer < rhs.m_value.number_integer; - if (errno == 0) - { - value_unsigned = static_cast(x); - if (value_unsigned == x) - { - return token_type::value_unsigned; - } - } - } - else if (number_type == token_type::value_integer) - { - char* endptr = nullptr; - errno = 0; - const auto x = std::strtoll(yytext.data(), &endptr, 10); + case value_t::number_unsigned: + return lhs.m_value.number_unsigned < rhs.m_value.number_unsigned; - // we checked the number format before - assert(endptr == yytext.data() + yylen); + case value_t::number_float: + return lhs.m_value.number_float < rhs.m_value.number_float; - if (errno == 0) - { - value_integer = static_cast(x); - if (value_integer == x) - { - return token_type::value_integer; - } - } + default: + return false; } - - // this code is reached if we parse a floating-point number or if - // an integer conversion above failed - strtof(value_float, yytext.data(), nullptr); - return token_type::value_float; } - - token_type scan_true() + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) { - assert(current == 't'); - if (JSON_LIKELY((get() == 'r' and get() == 'u' and get() == 'e'))) - { - return token_type::literal_true; - } - - error_message = "invalid literal; expected 'true'"; - return token_type::parse_error; + return static_cast(lhs.m_value.number_integer) < rhs.m_value.number_float; } - - token_type scan_false() + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) { - assert(current == 'f'); - if (JSON_LIKELY((get() == 'a' and get() == 'l' and get() == 's' and get() == 'e'))) - { - return token_type::literal_false; - } - - error_message = "invalid literal; expected 'false'"; - return token_type::parse_error; + return lhs.m_value.number_float < static_cast(rhs.m_value.number_integer); } - - token_type scan_null() + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) { - assert(current == 'n'); - if (JSON_LIKELY((get() == 'u' and get() == 'l' and get() == 'l'))) - { - return token_type::literal_null; - } - - error_message = "invalid literal; expected 'null'"; - return token_type::parse_error; + return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_float; + } + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) + { + return lhs.m_value.number_float < static_cast(rhs.m_value.number_unsigned); + } + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) + { + return lhs.m_value.number_integer < static_cast(rhs.m_value.number_unsigned); + } + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) + { + return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_integer; } - ///////////////////// - // input management - ///////////////////// + // We only reach this line if we cannot compare values. In that case, + // we compare types. Note we have to call the operator explicitly, + // because MSVC has problems otherwise. + return operator<(lhs_type, rhs_type); + } + + /*! + @brief comparison: less than + @copydoc operator<(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs < basic_json(rhs)); + } + + /*! + @brief comparison: less than + @copydoc operator<(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) < rhs); + } - /// reset yytext - void reset() noexcept - { - yylen = 0; - start_pos = chars_read - 1; - } + /*! + @brief comparison: less than or equal - /// get a character from the input - int get() - { - ++chars_read; - return next_unget - ? (next_unget = false, current) - : (current = ia->get_character()); - } + Compares whether one JSON value @a lhs is less than or equal to another + JSON value by calculating `not (rhs < lhs)`. - /// add a character to yytext - void add(int c) - { - // resize yytext if necessary; this condition is deemed unlikely, - // because we start with a 1024-byte buffer - if (JSON_UNLIKELY((yylen + 1 > yytext.capacity()))) - { - yytext.resize(2 * yytext.capacity(), '\0'); - } - yytext[yylen++] = static_cast(c); - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is less than or equal to @a rhs - public: - ///////////////////// - // value getters - ///////////////////// + @complexity Linear. - /// return integer value - constexpr number_integer_t get_number_integer() const noexcept - { - return value_integer; - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - /// return unsigned integer value - constexpr number_unsigned_t get_number_unsigned() const noexcept - { - return value_unsigned; - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__greater} - /// return floating-point value - constexpr number_float_t get_number_float() const noexcept - { - return value_float; - } + @since version 1.0.0 + */ + friend bool operator<=(const_reference lhs, const_reference rhs) noexcept + { + return not (rhs < lhs); + } - /// return string value - const std::string get_string() - { - // yytext cannot be returned as char*, because it may contain a - // null byte (parsed as "\u0000") - return std::string(yytext.data(), yylen); - } + /*! + @brief comparison: less than or equal + @copydoc operator<=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<=(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs <= basic_json(rhs)); + } - ///////////////////// - // diagnostics - ///////////////////// + /*! + @brief comparison: less than or equal + @copydoc operator<=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<=(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) <= rhs); + } - /// return position of last read token - constexpr size_t get_position() const noexcept - { - return chars_read; - } + /*! + @brief comparison: greater than - /// return the last read token (for errors only) - std::string get_token_string() const - { - // get the raw byte sequence of the last token - std::string s = ia->read(start_pos, chars_read - start_pos); + Compares whether one JSON value @a lhs is greater than another + JSON value by calculating `not (lhs <= rhs)`. - // escape control characters - std::string result; - for (auto c : s) - { - if (c == '\0' or c == std::char_traits::eof()) - { - // ignore EOF - continue; - } - else if ('\x00' <= c and c <= '\x1f') - { - // escape control characters - result += "<" + codepoint_to_string(c) + ">"; - } - else - { - // add character as is - result.append(1, c); - } - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is greater than to @a rhs - return result; - } + @complexity Linear. - /// return syntax error message - const std::string& get_error_message() const noexcept - { - return error_message; - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - ///////////////////// - // actual scanner - ///////////////////// + @liveexample{The example demonstrates comparing several JSON + types.,operator__lessequal} - token_type scan() - { - // read next character and ignore whitespace - do - { - get(); - } - while (current == ' ' or current == '\t' or current == '\n' or current == '\r'); - - switch (current) - { - // structural characters - case '[': - return token_type::begin_array; - case ']': - return token_type::end_array; - case '{': - return token_type::begin_object; - case '}': - return token_type::end_object; - case ':': - return token_type::name_separator; - case ',': - return token_type::value_separator; - - // literals - case 't': - return scan_true(); - case 'f': - return scan_false(); - case 'n': - return scan_null(); - - // string - case '\"': - return scan_string(); - - // number - case '-': - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - return scan_number(); - - // end of input (the null byte is needed when parsing from - // string literals) - case '\0': - case std::char_traits::eof(): - return token_type::end_of_input; + @since version 1.0.0 + */ + friend bool operator>(const_reference lhs, const_reference rhs) noexcept + { + return not (lhs <= rhs); + } - // error - default: - error_message = "invalid literal"; - return token_type::parse_error; - } - } + /*! + @brief comparison: greater than + @copydoc operator>(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs > basic_json(rhs)); + } - private: - /// input adapter - input_adapter_t ia = nullptr; + /*! + @brief comparison: greater than + @copydoc operator>(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) > rhs); + } - /// the current character - int current = std::char_traits::eof(); + /*! + @brief comparison: greater than or equal - /// whether get() should return the last character again - bool next_unget = false; + Compares whether one JSON value @a lhs is greater than or equal to another + JSON value by calculating `not (lhs < rhs)`. - /// the number of characters read - size_t chars_read = 0; - /// the start position of the current token - size_t start_pos = 0; + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is greater than or equal to @a rhs - /// buffer for variable-length tokens (numbers, strings) - std::vector yytext = std::vector(1024, '\0'); - /// current index in yytext - size_t yylen = 0; + @complexity Linear. - /// a description of occurred lexer errors - std::string error_message = ""; + @exceptionsafety No-throw guarantee: this function never throws exceptions. - // number values - number_integer_t value_integer = 0; - number_unsigned_t value_unsigned = 0; - number_float_t value_float = 0; + @liveexample{The example demonstrates comparing several JSON + types.,operator__greaterequal} - /// the decimal point - const char decimal_point_char = '.'; - }; + @since version 1.0.0 + */ + friend bool operator>=(const_reference lhs, const_reference rhs) noexcept + { + return not (lhs < rhs); + } /*! - @brief syntax analysis - - This class implements a recursive decent parser. + @brief comparison: greater than or equal + @copydoc operator>=(const_reference, const_reference) */ - class parser + template::value, int>::type = 0> + friend bool operator>=(const_reference lhs, const ScalarType rhs) noexcept { - public: - /// a parser reading from an input adapter - explicit parser(input_adapter_t adapter, - const parser_callback_t cb = nullptr) - : callback(cb), m_lexer(adapter) - {} - - /*! - @brief public parser interface + return (lhs >= basic_json(rhs)); + } - @param[in] strict whether to expect the last token to be EOF - @return parsed JSON value + /*! + @brief comparison: greater than or equal + @copydoc operator>=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>=(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) >= rhs); + } - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - */ - basic_json parse(const bool strict = true) - { - // read first token - get_token(); + /// @} - basic_json result = parse_internal(true); - result.assert_invariant(); + /////////////////// + // serialization // + /////////////////// - if (strict) - { - get_token(); - expect(lexer::token_type::end_of_input); - } + /// @name serialization + /// @{ - // return parser result and replace it with null in case the - // top-level value was discarded by the callback function - return result.is_discarded() ? basic_json() : std::move(result); - } + /*! + @brief serialize to stream - /*! - @brief public accept interface + Serialize the given JSON value @a j to the output stream @a o. The JSON + value will be serialized using the @ref dump member function. - @param[in] strict whether to expect the last token to be EOF - @return whether the input is a proper JSON text - */ - bool accept(const bool strict = true) - { - // read first token - get_token(); + - The indentation of the output can be controlled with the member variable + `width` of the output stream @a o. For instance, using the manipulator + `std::setw(4)` on @a o sets the indentation level to `4` and the + serialization result is the same as calling `dump(4)`. - if (not accept_internal()) - { - return false; - } + - The indentation character can be controlled with the member variable + `fill` of the output stream @a o. For instance, the manipulator + `std::setfill('\\t')` sets indentation to use a tab character rather than + the default space character. - if (strict and get_token() != lexer::token_type::end_of_input) - { - return false; - } + @param[in,out] o stream to serialize to + @param[in] j JSON value to serialize - return true; - } + @return the stream @a o - private: - /*! - @brief the actual parser - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - */ - basic_json parse_internal(bool keep) - { - auto result = basic_json(value_t::discarded); + @throw type_error.316 if a string stored inside the JSON value is not + UTF-8 encoded - switch (last_token) - { - case lexer::token_type::begin_object: - { - if (keep and (not callback - or ((keep = callback(depth++, parse_event_t::object_start, result)) != 0))) - { - // explicitly set result to object to cope with {} - result.m_type = value_t::object; - result.m_value = value_t::object; - } + @complexity Linear. - // read next token - get_token(); + @liveexample{The example below shows the serialization with different + parameters to `width` to adjust the indentation level.,operator_serialize} - // closing } -> we are done - if (last_token == lexer::token_type::end_object) - { - if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } + @since version 1.0.0; indentation character added in version 3.0.0 + */ + friend std::ostream& operator<<(std::ostream& o, const basic_json& j) + { + // read width member and use it as indentation parameter if nonzero + const bool pretty_print = (o.width() > 0); + const auto indentation = (pretty_print ? o.width() : 0); - // parse values - while (true) - { - // store key - expect(lexer::token_type::value_string); - const auto key = m_lexer.get_string(); + // reset width to 0 for subsequent calls to this stream + o.width(0); - bool keep_tag = false; - if (keep) - { - if (callback) - { - basic_json k(key); - keep_tag = callback(depth, parse_event_t::key, k); - } - else - { - keep_tag = true; - } - } + // do the actual serialization + serializer s(detail::output_adapter(o), o.fill()); + s.dump(j, pretty_print, false, static_cast(indentation)); + return o; + } - // parse separator (:) - get_token(); - expect(lexer::token_type::name_separator); + /*! + @brief serialize to stream + @deprecated This stream operator is deprecated and will be removed in + future 4.0.0 of the library. Please use + @ref operator<<(std::ostream&, const basic_json&) + instead; that is, replace calls like `j >> o;` with `o << j;`. + @since version 1.0.0; deprecated since version 3.0.0 + */ + JSON_DEPRECATED + friend std::ostream& operator>>(const basic_json& j, std::ostream& o) + { + return o << j; + } - // parse and add value - get_token(); - auto value = parse_internal(keep); - if (keep and keep_tag and not value.is_discarded()) - { - result[key] = std::move(value); - } + /// @} - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } - // closing } - expect(lexer::token_type::end_object); - break; - } + ///////////////////// + // deserialization // + ///////////////////// - if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) - { - result = basic_json(value_t::discarded); - } + /// @name deserialization + /// @{ - return result; - } + /*! + @brief deserialize from a compatible input + + This function reads from a compatible input. Examples are: + - an array of 1-byte values + - strings with character/literal type with size of 1 byte + - input streams + - container with contiguous storage of 1-byte values. Compatible container + types include `std::vector`, `std::string`, `std::array`, + `std::valarray`, and `std::initializer_list`. Furthermore, C-style + arrays can be used with `std::begin()`/`std::end()`. User-defined + containers can be used as long as they implement random-access iterators + and a contiguous storage. - case lexer::token_type::begin_array: - { - if (keep and (not callback - or ((keep = callback(depth++, parse_event_t::array_start, result)) != 0))) - { - // explicitly set result to object to cope with [] - result.m_type = value_t::array; - result.m_value = value_t::array; - } + @pre Each element of the container has a size of 1 byte. Violating this + precondition yields undefined behavior. **This precondition is enforced + with a static assertion.** - // read next token - get_token(); + @pre The container storage is contiguous. Violating this precondition + yields undefined behavior. **This precondition is enforced with an + assertion.** + @pre Each element of the container has a size of 1 byte. Violating this + precondition yields undefined behavior. **This precondition is enforced + with a static assertion.** - // closing ] -> we are done - if (last_token == lexer::token_type::end_array) - { - if (callback and not callback(--depth, parse_event_t::array_end, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } + @warning There is no way to enforce all preconditions at compile-time. If + the function is called with a noncompliant container and with + assertions switched off, the behavior is undefined and will most + likely yield segmentation violation. - // parse values - while (true) - { - // parse value - auto value = parse_internal(keep); - if (keep and not value.is_discarded()) - { - result.push_back(std::move(value)); - } + @param[in] i input to read from + @param[in] cb a parser callback function of type @ref parser_callback_t + which is used to control the deserialization by filtering unwanted values + (optional) - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + @return result of the deserialization - // closing ] - expect(lexer::token_type::end_array); - break; - } + @throw parse_error.101 if a parse error occurs; example: `""unexpected end + of input; expected string literal""` + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails - if (keep and callback and not callback(--depth, parse_event_t::array_end, result)) - { - result = basic_json(value_t::discarded); - } + @complexity Linear in the length of the input. The parser is a predictive + LL(1) parser. The complexity can be higher if the parser callback function + @a cb has a super-linear complexity. - return result; - } + @note A UTF-8 byte order mark is silently ignored. - case lexer::token_type::literal_null: - { - result.m_type = value_t::null; - break; - } + @liveexample{The example below demonstrates the `parse()` function reading + from an array.,parse__array__parser_callback_t} - case lexer::token_type::value_string: - { - result = basic_json(m_lexer.get_string()); - break; - } + @liveexample{The example below demonstrates the `parse()` function with + and without callback function.,parse__string__parser_callback_t} - case lexer::token_type::literal_true: - { - result.m_type = value_t::boolean; - result.m_value = true; - break; - } + @liveexample{The example below demonstrates the `parse()` function with + and without callback function.,parse__istream__parser_callback_t} - case lexer::token_type::literal_false: - { - result.m_type = value_t::boolean; - result.m_value = false; - break; - } + @liveexample{The example below demonstrates the `parse()` function reading + from a contiguous container.,parse__contiguouscontainer__parser_callback_t} - case lexer::token_type::value_unsigned: - { - result.m_type = value_t::number_unsigned; - result.m_value = m_lexer.get_number_unsigned(); - break; - } + @since version 2.0.3 (contiguous containers) + */ + static basic_json parse(detail::input_adapter&& i, + const parser_callback_t cb = nullptr, + const bool allow_exceptions = true) + { + basic_json result; + parser(i, cb, allow_exceptions).parse(true, result); + return result; + } - case lexer::token_type::value_integer: - { - result.m_type = value_t::number_integer; - result.m_value = m_lexer.get_number_integer(); - break; - } + static bool accept(detail::input_adapter&& i) + { + return parser(i).accept(true); + } - case lexer::token_type::value_float: - { - result.m_type = value_t::number_float; - result.m_value = m_lexer.get_number_float(); + static bool sax_parse(detail::input_adapter&& i, json_sax_t* sax, + input_format_t format = input_format_t::json, + const bool strict = true) + { + assert(sax); + switch (format) + { + case input_format_t::json: + return parser(std::move(i)).sax_parse(sax, strict); + default: + return binary_reader(std::move(i)).sax_parse(format, sax, strict); + } + } - // throw in case of infinity or NAN - if (JSON_UNLIKELY(not std::isfinite(result.m_value.number_float))) - { - JSON_THROW(out_of_range::create(406, "number overflow parsing '" + m_lexer.get_token_string() + "'")); - } + /*! + @brief deserialize from an iterator range with contiguous storage - break; - } + This function reads from an iterator range of a container with contiguous + storage of 1-byte values. Compatible container types include + `std::vector`, `std::string`, `std::array`, `std::valarray`, and + `std::initializer_list`. Furthermore, C-style arrays can be used with + `std::begin()`/`std::end()`. User-defined containers can be used as long + as they implement random-access iterators and a contiguous storage. - default: - { - // the last token was unexpected - unexpect(last_token); - } - } + @pre The iterator range is contiguous. Violating this precondition yields + undefined behavior. **This precondition is enforced with an assertion.** + @pre Each element in the range has a size of 1 byte. Violating this + precondition yields undefined behavior. **This precondition is enforced + with a static assertion.** - if (keep and callback and not callback(depth, parse_event_t::value, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } + @warning There is no way to enforce all preconditions at compile-time. If + the function is called with noncompliant iterators and with + assertions switched off, the behavior is undefined and will most + likely yield segmentation violation. - /*! - @brief the acutal acceptor + @tparam IteratorType iterator of container with contiguous storage + @param[in] first begin of the range to parse (included) + @param[in] last end of the range to parse (excluded) + @param[in] cb a parser callback function of type @ref parser_callback_t + which is used to control the deserialization by filtering unwanted values + (optional) + @param[in] allow_exceptions whether to throw exceptions in case of a + parse error (optional, true by default) - @invariant 1. The last token is not yet processed. Therefore, the - caller of this function must make sure a token has - been read. - 2. When this function returns, the last token is processed. - That is, the last read character was already considered. + @return result of the deserialization - This invariant makes sure that no token needs to be "unput". - */ - bool accept_internal() - { - switch (last_token) - { - case lexer::token_type::begin_object: - { - // read next token - get_token(); + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails - // closing } -> we are done - if (last_token == lexer::token_type::end_object) - { - return true; - } + @complexity Linear in the length of the input. The parser is a predictive + LL(1) parser. The complexity can be higher if the parser callback function + @a cb has a super-linear complexity. - // parse values - while (true) - { - // parse key - if (last_token != lexer::token_type::value_string) - { - return false; - } + @note A UTF-8 byte order mark is silently ignored. - // parse separator (:) - get_token(); - if (last_token != lexer::token_type::name_separator) - { - return false; - } + @liveexample{The example below demonstrates the `parse()` function reading + from an iterator range.,parse__iteratortype__parser_callback_t} - // parse value - get_token(); - if (not accept_internal()) - { - return false; - } + @since version 2.0.3 + */ + template::iterator_category>::value, int>::type = 0> + static basic_json parse(IteratorType first, IteratorType last, + const parser_callback_t cb = nullptr, + const bool allow_exceptions = true) + { + basic_json result; + parser(detail::input_adapter(first, last), cb, allow_exceptions).parse(true, result); + return result; + } - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + template::iterator_category>::value, int>::type = 0> + static bool accept(IteratorType first, IteratorType last) + { + return parser(detail::input_adapter(first, last)).accept(true); + } - // closing } - if (last_token != lexer::token_type::end_object) - { - return false; - } + template::iterator_category>::value, int>::type = 0> + static bool sax_parse(IteratorType first, IteratorType last, json_sax_t* sax) + { + return parser(detail::input_adapter(first, last)).sax_parse(sax); + } - return true; - } - } + /*! + @brief deserialize from stream + @deprecated This stream operator is deprecated and will be removed in + version 4.0.0 of the library. Please use + @ref operator>>(std::istream&, basic_json&) + instead; that is, replace calls like `j << i;` with `i >> j;`. + @since version 1.0.0; deprecated since version 3.0.0 + */ + JSON_DEPRECATED + friend std::istream& operator<<(basic_json& j, std::istream& i) + { + return operator>>(i, j); + } - case lexer::token_type::begin_array: - { - // read next token - get_token(); + /*! + @brief deserialize from stream - // closing ] -> we are done - if (last_token == lexer::token_type::end_array) - { - return true; - } + Deserializes an input stream to a JSON value. - // parse values - while (true) - { - // parse value - if (not accept_internal()) - { - return false; - } + @param[in,out] i input stream to read a serialized JSON value from + @param[in,out] j JSON value to write the deserialized input to - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails - // closing ] - if (last_token != lexer::token_type::end_array) - { - return false; - } + @complexity Linear in the length of the input. The parser is a predictive + LL(1) parser. - return true; - } - } + @note A UTF-8 byte order mark is silently ignored. - case lexer::token_type::literal_false: - case lexer::token_type::literal_null: - case lexer::token_type::literal_true: - case lexer::token_type::value_float: - case lexer::token_type::value_integer: - case lexer::token_type::value_string: - case lexer::token_type::value_unsigned: - { - return true; - } + @liveexample{The example below shows how a JSON value is constructed by + reading a serialization from a stream.,operator_deserialize} - default: - { - // the last token was unexpected - return false; - } - } - } + @sa parse(std::istream&, const parser_callback_t) for a variant with a + parser callback function to filter values while parsing - /// get next token from lexer - typename lexer::token_type get_token() - { - last_token = m_lexer.scan(); - return last_token; - } + @since version 1.0.0 + */ + friend std::istream& operator>>(std::istream& i, basic_json& j) + { + parser(detail::input_adapter(i)).parse(false, j); + return i; + } - /*! - @throw parse_error.101 if expected token did not occur - */ - void expect(typename lexer::token_type t) const - { - if (JSON_UNLIKELY(t != last_token)) - { - std::string error_msg = "syntax error - "; - if (last_token == lexer::token_type::parse_error) - { - error_msg += m_lexer.get_error_message() + "; last read: '" + m_lexer.get_token_string() + "'"; - } - else - { - error_msg += "unexpected " + std::string(lexer::token_type_name(last_token)); - } + /// @} - error_msg += "; expected " + std::string(lexer::token_type_name(t)); - JSON_THROW(parse_error::create(101, m_lexer.get_position(), error_msg)); - } - } + /////////////////////////// + // convenience functions // + /////////////////////////// - /*! - @throw parse_error.101 if unexpected token occurred - */ - void unexpect(typename lexer::token_type t) const - { - if (JSON_UNLIKELY(t == last_token)) - { - std::string error_msg = "syntax error - "; - if (last_token == lexer::token_type::parse_error) - { - error_msg += m_lexer.get_error_message() + "; last read '" + m_lexer.get_token_string() + "'"; - } - else - { - error_msg += "unexpected " + std::string(lexer::token_type_name(last_token)); - } + /*! + @brief return the type as string - JSON_THROW(parse_error::create(101, m_lexer.get_position(), error_msg)); - } - } + Returns the type name as string to be used in error messages - usually to + indicate that a function was called on a wrong JSON type. + + @return a string representation of a the @a m_type member: + Value type | return value + ----------- | ------------- + null | `"null"` + boolean | `"boolean"` + string | `"string"` + number | `"number"` (for all number types) + object | `"object"` + array | `"array"` + discarded | `"discarded"` - private: - /// current level of recursion - int depth = 0; - /// callback function - const parser_callback_t callback = nullptr; - /// the type of the last read token - typename lexer::token_type last_token = lexer::token_type::uninitialized; - /// the lexer - lexer m_lexer; - }; + @exceptionsafety No-throw guarantee: this function never throws exceptions. - public: - /*! - @brief JSON Pointer + @complexity Constant. - A JSON pointer defines a string syntax for identifying a specific value - within a JSON document. It can be used with functions `at` and - `operator[]`. Furthermore, JSON pointers are the base for JSON patches. + @liveexample{The following code exemplifies `type_name()` for all JSON + types.,type_name} - @sa [RFC 6901](https://tools.ietf.org/html/rfc6901) + @sa @ref type() -- return the type of the JSON value + @sa @ref operator value_t() -- return the type of the JSON value (implicit) - @since version 2.0.0 + @since version 1.0.0, public since 2.1.0, `const char*` and `noexcept` + since 3.0.0 */ - class json_pointer + const char* type_name() const noexcept { - /// allow basic_json to access private members - friend class basic_json; - - public: - /*! - @brief create JSON pointer - - Create a JSON pointer according to the syntax described in - [Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3). - - @param[in] s string representing the JSON pointer; if omitted, the - empty string is assumed which references the whole JSON - value + { + switch (m_type) + { + case value_t::null: + return "null"; + case value_t::object: + return "object"; + case value_t::array: + return "array"; + case value_t::string: + return "string"; + case value_t::boolean: + return "boolean"; + case value_t::discarded: + return "discarded"; + default: + return "number"; + } + } + } - @throw parse_error.107 if the given JSON pointer @a s is nonempty and - does not begin with a slash (`/`); see example below - @throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s - is not followed by `0` (representing `~`) or `1` (representing `/`); - see example below + private: + ////////////////////// + // member variables // + ////////////////////// - @liveexample{The example shows the construction several valid JSON - pointers as well as the exceptional behavior.,json_pointer} + /// the type of the current element + value_t m_type = value_t::null; - @since version 2.0.0 - */ - explicit json_pointer(const std::string& s = "") - : reference_tokens(split(s)) - {} + /// the value of the current element + json_value m_value = {}; - /*! - @brief return a string representation of the JSON pointer + ////////////////////////////////////////// + // binary serialization/deserialization // + ////////////////////////////////////////// - @invariant For each JSON pointer `ptr`, it holds: - @code {.cpp} - ptr == json_pointer(ptr.to_string()); - @endcode + /// @name binary serialization/deserialization support + /// @{ - @return a string representation of the JSON pointer + public: + /*! + @brief create a CBOR serialization of a given JSON value - @liveexample{The example shows the result of `to_string`., - json_pointer__to_string} + Serializes a given JSON value @a j to a byte vector using the CBOR (Concise + Binary Object Representation) serialization format. CBOR is a binary + serialization format which aims to be more compact than JSON itself, yet + more efficient to parse. - @since version 2.0.0 - */ - std::string to_string() const noexcept - { - return std::accumulate(reference_tokens.begin(), - reference_tokens.end(), std::string{}, - [](const std::string & a, const std::string & b) - { - return a + "/" + escape(b); - }); - } + The library uses the following mapping from JSON values types to + CBOR types according to the CBOR specification (RFC 7049): - /// @copydoc to_string() - operator std::string() const - { - return to_string(); - } + JSON value type | value/range | CBOR type | first byte + --------------- | ------------------------------------------ | ---------------------------------- | --------------- + null | `null` | Null | 0xF6 + boolean | `true` | True | 0xF5 + boolean | `false` | False | 0xF4 + number_integer | -9223372036854775808..-2147483649 | Negative integer (8 bytes follow) | 0x3B + number_integer | -2147483648..-32769 | Negative integer (4 bytes follow) | 0x3A + number_integer | -32768..-129 | Negative integer (2 bytes follow) | 0x39 + number_integer | -128..-25 | Negative integer (1 byte follow) | 0x38 + number_integer | -24..-1 | Negative integer | 0x20..0x37 + number_integer | 0..23 | Integer | 0x00..0x17 + number_integer | 24..255 | Unsigned integer (1 byte follow) | 0x18 + number_integer | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 + number_integer | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A + number_integer | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B + number_unsigned | 0..23 | Integer | 0x00..0x17 + number_unsigned | 24..255 | Unsigned integer (1 byte follow) | 0x18 + number_unsigned | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 + number_unsigned | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A + number_unsigned | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B + number_float | *any value* | Double-Precision Float | 0xFB + string | *length*: 0..23 | UTF-8 string | 0x60..0x77 + string | *length*: 23..255 | UTF-8 string (1 byte follow) | 0x78 + string | *length*: 256..65535 | UTF-8 string (2 bytes follow) | 0x79 + string | *length*: 65536..4294967295 | UTF-8 string (4 bytes follow) | 0x7A + string | *length*: 4294967296..18446744073709551615 | UTF-8 string (8 bytes follow) | 0x7B + array | *size*: 0..23 | array | 0x80..0x97 + array | *size*: 23..255 | array (1 byte follow) | 0x98 + array | *size*: 256..65535 | array (2 bytes follow) | 0x99 + array | *size*: 65536..4294967295 | array (4 bytes follow) | 0x9A + array | *size*: 4294967296..18446744073709551615 | array (8 bytes follow) | 0x9B + object | *size*: 0..23 | map | 0xA0..0xB7 + object | *size*: 23..255 | map (1 byte follow) | 0xB8 + object | *size*: 256..65535 | map (2 bytes follow) | 0xB9 + object | *size*: 65536..4294967295 | map (4 bytes follow) | 0xBA + object | *size*: 4294967296..18446744073709551615 | map (8 bytes follow) | 0xBB - private: - /*! - @brief remove and return last reference pointer - @throw out_of_range.405 if JSON pointer has no parent - */ - std::string pop_back() - { - if (is_root()) - { - JSON_THROW(out_of_range::create(405, "JSON pointer has no parent")); - } + @note The mapping is **complete** in the sense that any JSON value type + can be converted to a CBOR value. - auto last = reference_tokens.back(); - reference_tokens.pop_back(); - return last; - } + @note If NaN or Infinity are stored inside a JSON number, they are + serialized properly. This behavior differs from the @ref dump() + function which serializes NaN or Infinity to `null`. - /// return whether pointer points to the root document - bool is_root() const - { - return reference_tokens.empty(); - } + @note The following CBOR types are not used in the conversion: + - byte strings (0x40..0x5F) + - UTF-8 strings terminated by "break" (0x7F) + - arrays terminated by "break" (0x9F) + - maps terminated by "break" (0xBF) + - date/time (0xC0..0xC1) + - bignum (0xC2..0xC3) + - decimal fraction (0xC4) + - bigfloat (0xC5) + - tagged items (0xC6..0xD4, 0xD8..0xDB) + - expected conversions (0xD5..0xD7) + - simple values (0xE0..0xF3, 0xF8) + - undefined (0xF7) + - half and single-precision floats (0xF9-0xFA) + - break (0xFF) - json_pointer top() const - { - if (is_root()) - { - JSON_THROW(out_of_range::create(405, "JSON pointer has no parent")); - } + @param[in] j JSON value to serialize + @return MessagePack serialization as byte vector - json_pointer result = *this; - result.reference_tokens = {reference_tokens[0]}; - return result; - } + @complexity Linear in the size of the JSON value @a j. - /*! - @brief create and return a reference to the pointed to value + @liveexample{The example shows the serialization of a JSON value to a byte + vector in CBOR format.,to_cbor} - @complexity Linear in the number of reference tokens. + @sa http://cbor.io + @sa @ref from_cbor(detail::input_adapter, const bool strict) for the + analogous deserialization + @sa @ref to_msgpack(const basic_json&) for the related MessagePack format + @sa @ref to_ubjson(const basic_json&, const bool, const bool) for the + related UBJSON format - @throw parse_error.109 if array index is not a number - @throw type_error.313 if value cannot be unflattened - */ - reference get_and_create(reference j) const - { - pointer result = &j; + @since version 2.0.9 + */ + static std::vector to_cbor(const basic_json& j) + { + std::vector result; + to_cbor(j, result); + return result; + } - // in case no reference tokens exist, return a reference to the - // JSON value j which will be overwritten by a primitive value - for (const auto& reference_token : reference_tokens) - { - switch (result->m_type) - { - case value_t::null: - { - if (reference_token == "0") - { - // start a new array if reference token is 0 - result = &result->operator[](0); - } - else - { - // start a new object otherwise - result = &result->operator[](reference_token); - } - break; - } + static void to_cbor(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_cbor(j); + } - case value_t::object: - { - // create an entry in the object - result = &result->operator[](reference_token); - break; - } + static void to_cbor(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_cbor(j); + } - case value_t::array: - { - // create an entry in the array - JSON_TRY - { - result = &result->operator[](static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + /*! + @brief create a MessagePack serialization of a given JSON value - /* - The following code is only reached if there exists a - reference token _and_ the current value is primitive. In - this case, we have an error situation, because primitive - values may only occur as single value; that is, with an - empty list of reference tokens. - */ - default: - { - JSON_THROW(type_error::create(313, "invalid value to unflatten")); - } - } - } + Serializes a given JSON value @a j to a byte vector using the MessagePack + serialization format. MessagePack is a binary serialization format which + aims to be more compact than JSON itself, yet more efficient to parse. - return *result; - } + The library uses the following mapping from JSON values types to + MessagePack types according to the MessagePack specification: - /*! - @brief return a reference to the pointed to value + JSON value type | value/range | MessagePack type | first byte + --------------- | --------------------------------- | ---------------- | ---------- + null | `null` | nil | 0xC0 + boolean | `true` | true | 0xC3 + boolean | `false` | false | 0xC2 + number_integer | -9223372036854775808..-2147483649 | int64 | 0xD3 + number_integer | -2147483648..-32769 | int32 | 0xD2 + number_integer | -32768..-129 | int16 | 0xD1 + number_integer | -128..-33 | int8 | 0xD0 + number_integer | -32..-1 | negative fixint | 0xE0..0xFF + number_integer | 0..127 | positive fixint | 0x00..0x7F + number_integer | 128..255 | uint 8 | 0xCC + number_integer | 256..65535 | uint 16 | 0xCD + number_integer | 65536..4294967295 | uint 32 | 0xCE + number_integer | 4294967296..18446744073709551615 | uint 64 | 0xCF + number_unsigned | 0..127 | positive fixint | 0x00..0x7F + number_unsigned | 128..255 | uint 8 | 0xCC + number_unsigned | 256..65535 | uint 16 | 0xCD + number_unsigned | 65536..4294967295 | uint 32 | 0xCE + number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xCF + number_float | *any value* | float 64 | 0xCB + string | *length*: 0..31 | fixstr | 0xA0..0xBF + string | *length*: 32..255 | str 8 | 0xD9 + string | *length*: 256..65535 | str 16 | 0xDA + string | *length*: 65536..4294967295 | str 32 | 0xDB + array | *size*: 0..15 | fixarray | 0x90..0x9F + array | *size*: 16..65535 | array 16 | 0xDC + array | *size*: 65536..4294967295 | array 32 | 0xDD + object | *size*: 0..15 | fix map | 0x80..0x8F + object | *size*: 16..65535 | map 16 | 0xDE + object | *size*: 65536..4294967295 | map 32 | 0xDF - @note This version does not throw if a value is not present, but tries - to create nested values instead. For instance, calling this function - with pointer `"/this/that"` on a null value is equivalent to calling - `operator[]("this").operator[]("that")` on that value, effectively - changing the null value to an object. + @note The mapping is **complete** in the sense that any JSON value type + can be converted to a MessagePack value. - @param[in] ptr a JSON value + @note The following values can **not** be converted to a MessagePack value: + - strings with more than 4294967295 bytes + - arrays with more than 4294967295 elements + - objects with more than 4294967295 elements - @return reference to the JSON value pointed to by the JSON pointer + @note The following MessagePack types are not used in the conversion: + - bin 8 - bin 32 (0xC4..0xC6) + - ext 8 - ext 32 (0xC7..0xC9) + - float 32 (0xCA) + - fixext 1 - fixext 16 (0xD4..0xD8) - @complexity Linear in the length of the JSON pointer. + @note Any MessagePack output created @ref to_msgpack can be successfully + parsed by @ref from_msgpack. - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - reference get_unchecked(pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - // convert null values to arrays or objects before continuing - if (ptr->m_type == value_t::null) - { - // check if reference token is a number - const bool nums = std::all_of(reference_token.begin(), - reference_token.end(), - [](const char x) - { - return (x >= '0' and x <= '9'); - }); + @note If NaN or Infinity are stored inside a JSON number, they are + serialized properly. This behavior differs from the @ref dump() + function which serializes NaN or Infinity to `null`. - // change value to array for numbers or "-" or to object - // otherwise - if (nums or reference_token == "-") - { - *ptr = value_t::array; - } - else - { - *ptr = value_t::object; - } - } + @param[in] j JSON value to serialize + @return MessagePack serialization as byte vector - switch (ptr->m_type) - { - case value_t::object: - { - // use unchecked object access - ptr = &ptr->operator[](reference_token); - break; - } + @complexity Linear in the size of the JSON value @a j. - case value_t::array: - { - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + @liveexample{The example shows the serialization of a JSON value to a byte + vector in MessagePack format.,to_msgpack} - if (reference_token == "-") - { - // explicitly treat "-" as index beyond the end - ptr = &ptr->operator[](ptr->m_value.array->size()); - } - else - { - // convert array index to number; unchecked access - JSON_TRY - { - ptr = &ptr->operator[](static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - } - break; - } + @sa http://msgpack.org + @sa @ref from_msgpack(const std::vector&, const size_t) for the + analogous deserialization + @sa @ref to_cbor(const basic_json& for the related CBOR format + @sa @ref to_ubjson(const basic_json&, const bool, const bool) for the + related UBJSON format - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + @since version 2.0.9 + */ + static std::vector to_msgpack(const basic_json& j) + { + std::vector result; + to_msgpack(j, result); + return result; + } - return *ptr; - } + static void to_msgpack(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_msgpack(j); + } - /*! - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.402 if the array index '-' is used - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - reference get_checked(pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // note: at performs range check - ptr = &ptr->at(reference_token); - break; - } + static void to_msgpack(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_msgpack(j); + } - case value_t::array: - { - if (reference_token == "-") - { - // "-" always fails the range check - JSON_THROW(out_of_range::create(402, "array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } + /*! + @brief create a UBJSON serialization of a given JSON value - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + Serializes a given JSON value @a j to a byte vector using the UBJSON + (Universal Binary JSON) serialization format. UBJSON aims to be more compact + than JSON itself, yet more efficient to parse. - // note: at performs range check - JSON_TRY - { - ptr = &ptr->at(static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + The library uses the following mapping from JSON values types to + UBJSON types according to the UBJSON specification: + + JSON value type | value/range | UBJSON type | marker + --------------- | --------------------------------- | ----------- | ------ + null | `null` | null | `Z` + boolean | `true` | true | `T` + boolean | `false` | false | `F` + number_integer | -9223372036854775808..-2147483649 | int64 | `L` + number_integer | -2147483648..-32769 | int32 | `l` + number_integer | -32768..-129 | int16 | `I` + number_integer | -128..127 | int8 | `i` + number_integer | 128..255 | uint8 | `U` + number_integer | 256..32767 | int16 | `I` + number_integer | 32768..2147483647 | int32 | `l` + number_integer | 2147483648..9223372036854775807 | int64 | `L` + number_unsigned | 0..127 | int8 | `i` + number_unsigned | 128..255 | uint8 | `U` + number_unsigned | 256..32767 | int16 | `I` + number_unsigned | 32768..2147483647 | int32 | `l` + number_unsigned | 2147483648..9223372036854775807 | int64 | `L` + number_float | *any value* | float64 | `D` + string | *with shortest length indicator* | string | `S` + array | *see notes on optimized format* | array | `[` + object | *see notes on optimized format* | map | `{` - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + @note The mapping is **complete** in the sense that any JSON value type + can be converted to a UBJSON value. - return *ptr; - } + @note The following values can **not** be converted to a UBJSON value: + - strings with more than 9223372036854775807 bytes (theoretical) + - unsigned integer numbers above 9223372036854775807 - /*! - @brief return a const reference to the pointed to value + @note The following markers are not used in the conversion: + - `Z`: no-op values are not created. + - `C`: single-byte strings are serialized with `S` markers. - @param[in] ptr a JSON value + @note Any UBJSON output created @ref to_ubjson can be successfully parsed + by @ref from_ubjson. - @return const reference to the JSON value pointed to by the JSON - pointer + @note If NaN or Infinity are stored inside a JSON number, they are + serialized properly. This behavior differs from the @ref dump() + function which serializes NaN or Infinity to `null`. - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.402 if the array index '-' is used - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - const_reference get_unchecked(const_pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // use unchecked object access - ptr = &ptr->operator[](reference_token); - break; - } + @note The optimized formats for containers are supported: Parameter + @a use_size adds size information to the beginning of a container and + removes the closing marker. Parameter @a use_type further checks + whether all elements of a container have the same type and adds the + type marker to the beginning of the container. The @a use_type + parameter must only be used together with @a use_size = true. Note + that @a use_size = true alone may result in larger representations - + the benefit of this parameter is that the receiving side is + immediately informed on the number of elements of the container. - case value_t::array: - { - if (reference_token == "-") - { - // "-" cannot be used for const access - JSON_THROW(out_of_range::create(402, "array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } + @param[in] j JSON value to serialize + @param[in] use_size whether to add size annotations to container types + @param[in] use_type whether to add type annotations to container types + (must be combined with @a use_size = true) + @return UBJSON serialization as byte vector - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + @complexity Linear in the size of the JSON value @a j. - // use unchecked array access - JSON_TRY - { - ptr = &ptr->operator[](static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + @liveexample{The example shows the serialization of a JSON value to a byte + vector in UBJSON format.,to_ubjson} - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + @sa http://ubjson.org + @sa @ref from_ubjson(detail::input_adapter, const bool strict) for the + analogous deserialization + @sa @ref to_cbor(const basic_json& for the related CBOR format + @sa @ref to_msgpack(const basic_json&) for the related MessagePack format - return *ptr; - } + @since version 3.1.0 + */ + static std::vector to_ubjson(const basic_json& j, + const bool use_size = false, + const bool use_type = false) + { + std::vector result; + to_ubjson(j, result, use_size, use_type); + return result; + } - /*! - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.402 if the array index '-' is used - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - const_reference get_checked(const_pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // note: at performs range check - ptr = &ptr->at(reference_token); - break; - } + static void to_ubjson(const basic_json& j, detail::output_adapter o, + const bool use_size = false, const bool use_type = false) + { + binary_writer(o).write_ubjson(j, use_size, use_type); + } - case value_t::array: - { - if (reference_token == "-") - { - // "-" always fails the range check - JSON_THROW(out_of_range::create(402, "array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } + static void to_ubjson(const basic_json& j, detail::output_adapter o, + const bool use_size = false, const bool use_type = false) + { + binary_writer(o).write_ubjson(j, use_size, use_type); + } - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + /*! + @brief create a JSON value from an input in CBOR format - // note: at performs range check - JSON_TRY - { - ptr = &ptr->at(static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + Deserializes a given input @a i to a JSON value using the CBOR (Concise + Binary Object Representation) serialization format. - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + The library maps CBOR types to JSON value types as follows: - return *ptr; - } + CBOR type | JSON value type | first byte + ---------------------- | --------------- | ---------- + Integer | number_unsigned | 0x00..0x17 + Unsigned integer | number_unsigned | 0x18 + Unsigned integer | number_unsigned | 0x19 + Unsigned integer | number_unsigned | 0x1A + Unsigned integer | number_unsigned | 0x1B + Negative integer | number_integer | 0x20..0x37 + Negative integer | number_integer | 0x38 + Negative integer | number_integer | 0x39 + Negative integer | number_integer | 0x3A + Negative integer | number_integer | 0x3B + Negative integer | number_integer | 0x40..0x57 + UTF-8 string | string | 0x60..0x77 + UTF-8 string | string | 0x78 + UTF-8 string | string | 0x79 + UTF-8 string | string | 0x7A + UTF-8 string | string | 0x7B + UTF-8 string | string | 0x7F + array | array | 0x80..0x97 + array | array | 0x98 + array | array | 0x99 + array | array | 0x9A + array | array | 0x9B + array | array | 0x9F + map | object | 0xA0..0xB7 + map | object | 0xB8 + map | object | 0xB9 + map | object | 0xBA + map | object | 0xBB + map | object | 0xBF + False | `false` | 0xF4 + True | `true` | 0xF5 + Nill | `null` | 0xF6 + Half-Precision Float | number_float | 0xF9 + Single-Precision Float | number_float | 0xFA + Double-Precision Float | number_float | 0xFB - /*! - @brief split the string input to reference tokens + @warning The mapping is **incomplete** in the sense that not all CBOR + types can be converted to a JSON value. The following CBOR types + are not supported and will yield parse errors (parse_error.112): + - byte strings (0x40..0x5F) + - date/time (0xC0..0xC1) + - bignum (0xC2..0xC3) + - decimal fraction (0xC4) + - bigfloat (0xC5) + - tagged items (0xC6..0xD4, 0xD8..0xDB) + - expected conversions (0xD5..0xD7) + - simple values (0xE0..0xF3, 0xF8) + - undefined (0xF7) - @note This function is only called by the json_pointer constructor. - All exceptions below are documented there. + @warning CBOR allows map keys of any type, whereas JSON only allows + strings as keys in object values. Therefore, CBOR maps with keys + other than UTF-8 strings are rejected (parse_error.113). - @throw parse_error.107 if the pointer is not empty or begins with '/' - @throw parse_error.108 if character '~' is not followed by '0' or '1' - */ - static std::vector split(const std::string& reference_string) - { - std::vector result; + @note Any CBOR output created @ref to_cbor can be successfully parsed by + @ref from_cbor. - // special case: empty reference string -> no reference tokens - if (reference_string.empty()) - { - return result; - } + @param[in] i an input in CBOR format convertible to an input adapter + @param[in] strict whether to expect the input to be consumed until EOF + (true by default) + @param[in] allow_exceptions whether to throw exceptions in case of a + parse error (optional, true by default) - // check if nonempty reference string begins with slash - if (reference_string[0] != '/') - { - JSON_THROW(parse_error::create(107, 1, "JSON pointer must be empty or begin with '/' - was: '" + reference_string + "'")); - } + @return deserialized JSON value - // extract the reference tokens: - // - slash: position of the last read slash (or end of string) - // - start: position after the previous slash - for ( - // search for the first slash after the first character - size_t slash = reference_string.find_first_of('/', 1), - // set the beginning of the first reference token - start = 1; - // we can stop if start == string::npos+1 = 0 - start != 0; - // set the beginning of the next reference token - // (will eventually be 0 if slash == std::string::npos) - start = slash + 1, - // find next slash - slash = reference_string.find_first_of('/', start)) - { - // use the text between the beginning of the reference token - // (start) and the last slash (slash). - auto reference_token = reference_string.substr(start, slash - start); + @throw parse_error.110 if the given input ends prematurely or the end of + file was not reached when @a strict was set to true + @throw parse_error.112 if unsupported features from CBOR were + used in the given input @a v or if the input is not valid CBOR + @throw parse_error.113 if a string was expected as map key, but not found - // check reference tokens are properly escaped - for (size_t pos = reference_token.find_first_of('~'); - pos != std::string::npos; - pos = reference_token.find_first_of('~', pos + 1)) - { - assert(reference_token[pos] == '~'); + @complexity Linear in the size of the input @a i. - // ~ must be followed by 0 or 1 - if (pos == reference_token.size() - 1 or - (reference_token[pos + 1] != '0' and - reference_token[pos + 1] != '1')) - { - JSON_THROW(parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'")); - } - } + @liveexample{The example shows the deserialization of a byte vector in CBOR + format to a JSON value.,from_cbor} - // finally, store the reference token - unescape(reference_token); - result.push_back(reference_token); - } + @sa http://cbor.io + @sa @ref to_cbor(const basic_json&) for the analogous serialization + @sa @ref from_msgpack(detail::input_adapter, const bool, const bool) for the + related MessagePack format + @sa @ref from_ubjson(detail::input_adapter, const bool, const bool) for the + related UBJSON format - return result; - } + @since version 2.0.9; parameter @a start_index since 2.1.1; changed to + consume input adapters, removed start_index parameter, and added + @a strict parameter since 3.0.0; added @allow_exceptions parameter + since 3.2.0 + */ + static basic_json from_cbor(detail::input_adapter&& i, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::cbor, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } - /*! - @brief replace all occurrences of a substring by another string + /*! + @copydoc from_cbor(detail::input_adapter, const bool, const bool) + */ + template::value, int> = 0> + static basic_json from_cbor(A1 && a1, A2 && a2, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::cbor, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } - @param[in,out] s the string to manipulate; changed so that all - occurrences of @a f are replaced with @a t - @param[in] f the substring to replace with @a t - @param[in] t the string to replace @a f + /*! + @brief create a JSON value from an input in MessagePack format - @pre The search string @a f must not be empty. **This precondition is - enforced with an assertion.** + Deserializes a given input @a i to a JSON value using the MessagePack + serialization format. - @since version 2.0.0 - */ - static void replace_substring(std::string& s, - const std::string& f, - const std::string& t) - { - assert(not f.empty()); + The library maps MessagePack types to JSON value types as follows: - for ( - size_t pos = s.find(f); // find first occurrence of f - pos != std::string::npos; // make sure f was found - s.replace(pos, f.size(), t), // replace with t - pos = s.find(f, pos + t.size()) // find next occurrence of f - ); - } + MessagePack type | JSON value type | first byte + ---------------- | --------------- | ---------- + positive fixint | number_unsigned | 0x00..0x7F + fixmap | object | 0x80..0x8F + fixarray | array | 0x90..0x9F + fixstr | string | 0xA0..0xBF + nil | `null` | 0xC0 + false | `false` | 0xC2 + true | `true` | 0xC3 + float 32 | number_float | 0xCA + float 64 | number_float | 0xCB + uint 8 | number_unsigned | 0xCC + uint 16 | number_unsigned | 0xCD + uint 32 | number_unsigned | 0xCE + uint 64 | number_unsigned | 0xCF + int 8 | number_integer | 0xD0 + int 16 | number_integer | 0xD1 + int 32 | number_integer | 0xD2 + int 64 | number_integer | 0xD3 + str 8 | string | 0xD9 + str 16 | string | 0xDA + str 32 | string | 0xDB + array 16 | array | 0xDC + array 32 | array | 0xDD + map 16 | object | 0xDE + map 32 | object | 0xDF + negative fixint | number_integer | 0xE0-0xFF - /// escape tilde and slash - static std::string escape(std::string s) - { - // escape "~"" to "~0" and "/" to "~1" - replace_substring(s, "~", "~0"); - replace_substring(s, "/", "~1"); - return s; - } + @warning The mapping is **incomplete** in the sense that not all + MessagePack types can be converted to a JSON value. The following + MessagePack types are not supported and will yield parse errors: + - bin 8 - bin 32 (0xC4..0xC6) + - ext 8 - ext 32 (0xC7..0xC9) + - fixext 1 - fixext 16 (0xD4..0xD8) - /// unescape tilde and slash - static void unescape(std::string& s) - { - // first transform any occurrence of the sequence '~1' to '/' - replace_substring(s, "~1", "/"); - // then transform any occurrence of the sequence '~0' to '~' - replace_substring(s, "~0", "~"); - } + @note Any MessagePack output created @ref to_msgpack can be successfully + parsed by @ref from_msgpack. - /*! - @param[in] reference_string the reference string to the current value - @param[in] value the value to consider - @param[in,out] result the result object to insert values to + @param[in] i an input in MessagePack format convertible to an input + adapter + @param[in] strict whether to expect the input to be consumed until EOF + (true by default) + @param[in] allow_exceptions whether to throw exceptions in case of a + parse error (optional, true by default) - @note Empty objects or arrays are flattened to `null`. - */ - static void flatten(const std::string& reference_string, - const basic_json& value, - basic_json& result) - { - switch (value.m_type) - { - case value_t::array: - { - if (value.m_value.array->empty()) - { - // flatten empty array as null - result[reference_string] = nullptr; - } - else - { - // iterate array and use index as reference string - for (size_t i = 0; i < value.m_value.array->size(); ++i) - { - flatten(reference_string + "/" + std::to_string(i), - value.m_value.array->operator[](i), result); - } - } - break; - } + @return deserialized JSON value - case value_t::object: - { - if (value.m_value.object->empty()) - { - // flatten empty object as null - result[reference_string] = nullptr; - } - else - { - // iterate object and use keys as reference string - for (const auto& element : *value.m_value.object) - { - flatten(reference_string + "/" + escape(element.first), - element.second, result); - } - } - break; - } + @throw parse_error.110 if the given input ends prematurely or the end of + file was not reached when @a strict was set to true + @throw parse_error.112 if unsupported features from MessagePack were + used in the given input @a i or if the input is not valid MessagePack + @throw parse_error.113 if a string was expected as map key, but not found - default: - { - // add primitive value with its reference string - result[reference_string] = value; - break; - } - } - } + @complexity Linear in the size of the input @a i. - /*! - @param[in] value flattened JSON + @liveexample{The example shows the deserialization of a byte vector in + MessagePack format to a JSON value.,from_msgpack} - @return unflattened JSON + @sa http://msgpack.org + @sa @ref to_msgpack(const basic_json&) for the analogous serialization + @sa @ref from_cbor(detail::input_adapter, const bool, const bool) for the + related CBOR format + @sa @ref from_ubjson(detail::input_adapter, const bool, const bool) for + the related UBJSON format - @throw parse_error.109 if array index is not a number - @throw type_error.314 if value is not an object - @throw type_error.315 if object values are not primitive - @throw type_error.313 if value cannot be unflattened - */ - static basic_json unflatten(const basic_json& value) - { - if (not value.is_object()) - { - JSON_THROW(type_error::create(314, "only objects can be unflattened")); - } + @since version 2.0.9; parameter @a start_index since 2.1.1; changed to + consume input adapters, removed start_index parameter, and added + @a strict parameter since 3.0.0; added @allow_exceptions parameter + since 3.2.0 + */ + static basic_json from_msgpack(detail::input_adapter&& i, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::msgpack, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } - basic_json result; + /*! + @copydoc from_msgpack(detail::input_adapter, const bool, const bool) + */ + template::value, int> = 0> + static basic_json from_msgpack(A1 && a1, A2 && a2, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::msgpack, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } - // iterate the JSON object values - for (const auto& element : *value.m_value.object) - { - if (not element.second.is_primitive()) - { - JSON_THROW(type_error::create(315, "values in object must be primitive")); - } + /*! + @brief create a JSON value from an input in UBJSON format + + Deserializes a given input @a i to a JSON value using the UBJSON (Universal + Binary JSON) serialization format. + + The library maps UBJSON types to JSON value types as follows: + + UBJSON type | JSON value type | marker + ----------- | --------------------------------------- | ------ + no-op | *no value, next value is read* | `N` + null | `null` | `Z` + false | `false` | `F` + true | `true` | `T` + float32 | number_float | `d` + float64 | number_float | `D` + uint8 | number_unsigned | `U` + int8 | number_integer | `i` + int16 | number_integer | `I` + int32 | number_integer | `l` + int64 | number_integer | `L` + string | string | `S` + char | string | `C` + array | array (optimized values are supported) | `[` + object | object (optimized values are supported) | `{` + + @note The mapping is **complete** in the sense that any UBJSON value can + be converted to a JSON value. + + @param[in] i an input in UBJSON format convertible to an input adapter + @param[in] strict whether to expect the input to be consumed until EOF + (true by default) + @param[in] allow_exceptions whether to throw exceptions in case of a + parse error (optional, true by default) - // assign value to reference pointed to by JSON pointer; Note - // that if the JSON pointer is "" (i.e., points to the whole - // value), function get_and_create returns a reference to - // result itself. An assignment will then create a primitive - // value. - json_pointer(element.first).get_and_create(result) = element.second; - } + @return deserialized JSON value - return result; - } + @throw parse_error.110 if the given input ends prematurely or the end of + file was not reached when @a strict was set to true + @throw parse_error.112 if a parse error occurs + @throw parse_error.113 if a string could not be parsed successfully - friend bool operator==(json_pointer const& lhs, - json_pointer const& rhs) noexcept - { - return lhs.reference_tokens == rhs.reference_tokens; - } + @complexity Linear in the size of the input @a i. - friend bool operator!=(json_pointer const& lhs, - json_pointer const& rhs) noexcept - { - return !(lhs == rhs); - } + @liveexample{The example shows the deserialization of a byte vector in + UBJSON format to a JSON value.,from_ubjson} - /// the reference tokens - std::vector reference_tokens {}; - }; + @sa http://ubjson.org + @sa @ref to_ubjson(const basic_json&, const bool, const bool) for the + analogous serialization + @sa @ref from_cbor(detail::input_adapter, const bool, const bool) for the + related CBOR format + @sa @ref from_msgpack(detail::input_adapter, const bool, const bool) for + the related MessagePack format + + @since version 3.1.0; added @allow_exceptions parameter since 3.2.0 + */ + static basic_json from_ubjson(detail::input_adapter&& i, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::ubjson, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } + + /*! + @copydoc from_ubjson(detail::input_adapter, const bool, const bool) + */ + template::value, int> = 0> + static basic_json from_ubjson(A1 && a1, A2 && a2, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::ubjson, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } + + /// @} ////////////////////////// // JSON Pointer support // @@ -13750,6 +17681,9 @@ scan_number_done: pointer @a ptr. As `at` provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below. + @throw out_of_range.403 if the JSON pointer describes a key of an object + which cannot be found. See example below. + @throw out_of_range.404 if the JSON pointer @a ptr can not be resolved. See example below. @@ -13790,6 +17724,9 @@ scan_number_done: pointer @a ptr. As `at` provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below. + @throw out_of_range.403 if the JSON pointer describes a key of an object + which cannot be found. See example below. + @throw out_of_range.404 if the JSON pointer @a ptr can not be resolved. See example below. @@ -13857,7 +17794,7 @@ scan_number_done: @complexity Linear in the size the JSON value. @throw type_error.314 if value is not an object - @throw type_error.315 if object values are not primitve + @throw type_error.315 if object values are not primitive @liveexample{The following code shows how a flattened JSON object is unflattened into the original nested JSON object.,unflatten} @@ -14005,8 +17942,8 @@ scan_number_done: } else { - const auto idx = std::stoi(last_path); - if (static_cast(idx) > parent.size()) + const auto idx = json_pointer::array_index(last_path); + if (JSON_UNLIKELY(static_cast(idx) > parent.size())) { // avoid undefined behavior JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); @@ -14041,7 +17978,7 @@ scan_number_done: { // perform range check auto it = parent.find(last_path); - if (it != parent.end()) + if (JSON_LIKELY(it != parent.end())) { parent.erase(it); } @@ -14053,12 +17990,12 @@ scan_number_done: else if (parent.is_array()) { // note erase performs range check - parent.erase(static_cast(std::stoi(last_path))); + parent.erase(static_cast(json_pointer::array_index(last_path))); } }; // type check: top level value must be an array - if (not json_patch.is_array()) + if (JSON_UNLIKELY(not json_patch.is_array())) { JSON_THROW(parse_error::create(104, 0, "JSON patch must be an array of objects")); } @@ -14069,7 +18006,7 @@ scan_number_done: // wrapper to get a value for an operation const auto get_value = [&val](const std::string & op, const std::string & member, - bool string_type) -> basic_json& + bool string_type) -> basic_json & { // find value auto it = val.m_value.object->find(member); @@ -14078,13 +18015,13 @@ scan_number_done: const auto error_msg = (op == "op") ? "operation" : "operation '" + op + "'"; // check if desired value is present - if (it == val.m_value.object->end()) + if (JSON_UNLIKELY(it == val.m_value.object->end())) { JSON_THROW(parse_error::create(105, 0, error_msg + " must have member '" + member + "'")); } // check if result is of type string - if (string_type and not it->second.is_string()) + if (JSON_UNLIKELY(string_type and not it->second.is_string())) { JSON_THROW(parse_error::create(105, 0, error_msg + " must have string member '" + member + "'")); } @@ -14094,7 +18031,7 @@ scan_number_done: }; // type check: every element of the array must be an object - if (not val.is_object()) + if (JSON_UNLIKELY(not val.is_object())) { JSON_THROW(parse_error::create(104, 0, "JSON patch must be an array of objects")); } @@ -14144,11 +18081,16 @@ scan_number_done: case patch_operations::copy: { - const std::string from_path = get_value("copy", "from", true);; + const std::string from_path = get_value("copy", "from", true); const json_pointer from_ptr(from_path); // the "from" location must exist - use at() - result[ptr] = result.at(from_ptr); + basic_json v = result.at(from_ptr); + + // The copy is functionally identical to an "add" + // operation at the target location using the value + // specified in the "from" member. + operation_add(ptr, v); break; } @@ -14167,7 +18109,7 @@ scan_number_done: } // throw an exception if test fails - if (not success) + if (JSON_UNLIKELY(not success)) { JSON_THROW(other_error::create(501, "unsuccessful: " + val.dump())); } @@ -14214,13 +18156,13 @@ scan_number_done: diff for two JSON values.,diff} @sa @ref patch -- apply a JSON patch + @sa @ref merge_patch -- apply a JSON Merge Patch @sa [RFC 6902 (JSON Patch)](https://tools.ietf.org/html/rfc6902) @since version 2.0.0 */ - static basic_json diff(const basic_json& source, - const basic_json& target, + static basic_json diff(const basic_json& source, const basic_json& target, const std::string& path = "") { // the patch @@ -14237,9 +18179,7 @@ scan_number_done: // different types: replace value result.push_back( { - {"op", "replace"}, - {"path", path}, - {"value", target} + {"op", "replace"}, {"path", path}, {"value", target} }); } else @@ -14249,7 +18189,7 @@ scan_number_done: case value_t::array: { // first pass: traverse common elements - size_t i = 0; + std::size_t i = 0; while (i < source.size() and i < target.size()) { // recursive call to compare array values at index i @@ -14293,7 +18233,7 @@ scan_number_done: case value_t::object: { // first pass: traverse this object's elements - for (auto it = source.begin(); it != source.end(); ++it) + for (auto it = source.cbegin(); it != source.cend(); ++it) { // escape the key name to be used in a JSON patch const auto key = json_pointer::escape(it.key()); @@ -14309,14 +18249,13 @@ scan_number_done: // found a key that is not in o -> remove it result.push_back(object( { - {"op", "remove"}, - {"path", path + "/" + key} + {"op", "remove"}, {"path", path + "/" + key} })); } } // second pass: traverse other object's elements - for (auto it = target.begin(); it != target.end(); ++it) + for (auto it = target.cbegin(); it != target.cend(); ++it) { if (source.find(it.key()) == source.end()) { @@ -14324,8 +18263,7 @@ scan_number_done: const auto key = json_pointer::escape(it.key()); result.push_back( { - {"op", "add"}, - {"path", path + "/" + key}, + {"op", "add"}, {"path", path + "/" + key}, {"value", it.value()} }); } @@ -14339,9 +18277,7 @@ scan_number_done: // both primitive type: replace value result.push_back( { - {"op", "replace"}, - {"path", path}, - {"value", target} + {"op", "replace"}, {"path", path}, {"value", target} }); break; } @@ -14352,23 +18288,85 @@ scan_number_done: } /// @} -}; -///////////// -// presets // -///////////// + //////////////////////////////// + // JSON Merge Patch functions // + //////////////////////////////// -/*! -@brief default JSON class + /// @name JSON Merge Patch functions + /// @{ -This type is the default specialization of the @ref basic_json class which -uses the standard template types. + /*! + @brief applies a JSON Merge Patch + + The merge patch format is primarily intended for use with the HTTP PATCH + method as a means of describing a set of modifications to a target + resource's content. This function applies a merge patch to the current + JSON value. + + The function implements the following algorithm from Section 2 of + [RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396): + + ``` + define MergePatch(Target, Patch): + if Patch is an Object: + if Target is not an Object: + Target = {} // Ignore the contents and set it to an empty Object + for each Name/Value pair in Patch: + if Value is null: + if Name exists in Target: + remove the Name/Value pair from Target + else: + Target[Name] = MergePatch(Target[Name], Value) + return Target + else: + return Patch + ``` + + Thereby, `Target` is the current object; that is, the patch is applied to + the current value. + + @param[in] patch the patch to apply + + @complexity Linear in the lengths of @a patch. + + @liveexample{The following code shows how a JSON Merge Patch is applied to + a JSON document.,merge_patch} -@since version 1.0.0 -*/ -using json = basic_json<>; -} // namespace nlohmann + @sa @ref patch -- apply a JSON patch + @sa [RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396) + + @since version 3.0.0 + */ + void merge_patch(const basic_json& patch) + { + if (patch.is_object()) + { + if (not is_object()) + { + *this = object(); + } + for (auto it = patch.begin(); it != patch.end(); ++it) + { + if (it.value().is_null()) + { + erase(it.key()); + } + else + { + operator[](it.key()).merge_patch(it.value()); + } + } + } + else + { + *this = patch; + } + } + /// @} +}; +} // namespace nlohmann /////////////////////// // nonmember support // @@ -14410,8 +18408,10 @@ struct hash }; /// specialization for std::less -template <> -struct less<::nlohmann::detail::value_t> +/// @note: do not remove the space after '<', +/// see https://github.com/nlohmann/json/pull/679 +template<> +struct less< ::nlohmann::detail::value_t> { /*! @brief compare two value_t enum values @@ -14462,6 +18462,9 @@ inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std return nlohmann::json::json_pointer(std::string(s, n)); } +// #include + + // restore GCC/clang diagnostic settings #if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) #pragma GCC diagnostic pop @@ -14477,5 +18480,11 @@ inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std #undef JSON_LIKELY #undef JSON_UNLIKELY #undef JSON_DEPRECATED +#undef JSON_HAS_CPP_14 +#undef JSON_HAS_CPP_17 +#undef NLOHMANN_BASIC_JSON_TPL_DECLARATION +#undef NLOHMANN_BASIC_JSON_TPL +#undef NLOHMANN_JSON_HAS_HELPER + #endif diff --git a/src/page.h b/src/page.h index 9e65bbb..0f0f05f 100644 --- a/src/page.h +++ b/src/page.h @@ -114,6 +114,93 @@ namespace std } + +/** + * visitor to produc json representations of + * vallues stored in mstch::node + */ +class mstch_node_to_json: public boost::static_visitor { +public: + +// json operator()(const int& value) const { +// return json {value}; +// } +// +// json operator()(const double& value) const { +// return json {value}; +// } +// +// json operator()(const uint64_t& value) const { +// return json {value}; +// } +// +// json operator()(const int64_t& value) const { +// return json {value}; +// } +// +// json operator()(const uint32_t& value) const { +// return json {value}; +// } +// +// json operator()(const bool& value) const { +// return json {value}; +// } + + // enabled for numeric types + template + std::enable_if_t::value, nlohmann::json> + operator()(T const& value) const { + return nlohmann::json {value}; + } + + nlohmann::json operator()(std::string const& value) const { + return nlohmann::json {value}; + } + + nlohmann::json operator()(mstch::map const& n_map) const + { + nlohmann::json j; + + for (auto const& kv: n_map) + j[kv.first] = boost::apply_visitor(mstch_node_to_json(), kv.second); + + return j; + } + + nlohmann::json operator()(mstch::array const& n_array) const + { + nlohmann::json j; + + for (auto const& v: n_array) + j.push_back(boost::apply_visitor(mstch_node_to_json(), v)); + + return j; + + } + + // catch other types that are non-numeric and not listed above + template + std::enable_if_t::value, nlohmann::json> + operator()(const T&) const { + return nlohmann::json {}; + } + +}; + +namespace mstch +{ +namespace internal +{ + // add conversion from mstch::map to nlohmann::json + void + to_json(nlohmann::json& j, mstch::map const &m) + { + for (auto const& kv: m) + j[kv.first] = boost::apply_visitor(mstch_node_to_json(), kv.second); + } +} +} + namespace xmreg { @@ -125,6 +212,8 @@ using namespace std; using epee::string_tools::pod_to_hex; using epee::string_tools::hex_to_pod; + + /** * @brief The tx_details struct * @@ -273,80 +362,6 @@ struct tx_details }; -class my_render_node: public boost::static_visitor { -public: - -// my_render_node(json& _j) : j {_j} -// {} - - json operator()(const int& value) const { - //return std::to_string(value); - return json {value}; - } - - json operator()(const double& value) const { - return json {value}; - } - - json operator()(const uint64_t& value) const { - return json {value}; - } - - json operator()(const int64_t& value) const { - return json {value}; - } - - json operator()(const uint32_t& value) const { - return json {value}; - } - - json operator()(const bool& value) const { - return json {value}; - } - - json operator()(const string& value) const { - return json {value}; - } - - json operator()(const mstch::map& n_map) const - { - json j; - - for (auto const& kv: n_map) - { - j[kv.first] = boost::apply_visitor(my_render_node(), kv.second); - } - - return j; - - } - - json operator()(const mstch::array& n_array) const - { - json j; - - for (auto const& v: n_array) - j.push_back(boost::apply_visitor(my_render_node(), v)); - - return j; - - } - - json operator()(const mstch::lambda& value) const { - return json {"lambda"}; - } - - template - json operator()(const T&) const { - return json {}; - } - -//private: -// json &j; -}; - - - class page { @@ -4320,24 +4335,27 @@ public: return j_response; } + // get detailed tx information mstch::map tx_context = construct_tx_context(tx, 1 /*full detailed */); - std::string view{"{{#bold}}{{yay}} :){{/bold}}"}; - - json j; - //% boost::apply_visitor(my_render_node(j), kv.second); - - for (auto const& kv: tx_context) - { - //j_data[kv.first] = boost::apply_visitor(render_node2(), kv.second); - - //string a = boost::apply_visitor(my_render_node(), kv.second); - j[kv.first] = boost::apply_visitor(my_render_node(), kv.second); - - //cout << kv.first << " = " << a << endl; - } - - cout << j.dump() << '\n'; + // remove some page specific and html stuff + tx_context.erase("timescales"); + tx_context.erase("tx_json"); + tx_context.erase("tx_json_raw"); + tx_context.erase("enable_mixins_details"); + tx_context.erase("with_ring_signatures"); + tx_context.erase("show_part_of_inputs"); + tx_context.erase("show_more_details_link"); + tx_context.erase("max_no_of_inputs_to_show"); + tx_context.erase("inputs_xmr_sum_not_zero"); + tx_context.erase("have_raw_tx"); + tx_context.erase("have_any_unknown_amount"); + tx_context.erase("has_error"); + tx_context.erase("error_msg"); + tx_context.erase("server_time"); + tx_context.erase("construction_time"); + + j_data = tx_context; j_response["status"] = "success"; diff --git a/src/tools.h b/src/tools.h index 0321360..1063d20 100644 --- a/src/tools.h +++ b/src/tools.h @@ -370,6 +370,7 @@ calc_median(It it_begin, It it_end) void pause_execution(uint64_t no_seconds, const string& text = "now"); + } #endif //XMREG01_TOOLS_H \ No newline at end of file