7308 lines
227 KiB
Text
7308 lines
227 KiB
Text
/*!
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@mainpage
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These pages contain the API documentation of JSON for Modern C++, a C++11
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header-only JSON class.
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Class @ref nlohmann::basic_json is a good entry point for the documentation.
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@copyright The code is licensed under the [MIT
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License](http://opensource.org/licenses/MIT):
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<br>
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Copyright © 2013-2016 Niels Lohmann.
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<br>
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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<br>
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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<br>
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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@author [Niels Lohmann](http://nlohmann.me)
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@see https://github.com/nlohmann/json to download the source code
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@version 1.0.0
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*/
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#ifndef NLOHMANN_JSON_HPP
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#define NLOHMANN_JSON_HPP
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#include <algorithm>
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#include <array>
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#include <cassert>
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#include <ciso646>
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#include <cmath>
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#include <cstdio>
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#include <functional>
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#include <initializer_list>
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#include <iomanip>
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#include <iostream>
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#include <iterator>
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#include <limits>
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#include <map>
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#include <memory>
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#include <sstream>
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#include <string>
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#include <type_traits>
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#include <utility>
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#include <vector>
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// enable ssize_t on MinGW
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#ifdef __GNUC__
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#ifdef __MINGW32__
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#include <sys/types.h>
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#endif
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#endif
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// enable ssize_t for MSVC
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#ifdef _MSC_VER
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#include <basetsd.h>
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using ssize_t = SSIZE_T;
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#endif
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/*!
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@brief namespace for Niels Lohmann
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@see https://github.com/nlohmann
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@since version 1.0.0
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*/
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namespace nlohmann
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{
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/*!
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@brief unnamed namespace with internal helper functions
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@since version 1.0.0
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*/
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namespace
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{
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/*!
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@brief Helper to determine whether there's a key_type for T.
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@sa http://stackoverflow.com/a/7728728/266378
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*/
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template<typename T>
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struct has_mapped_type
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{
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private:
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template<typename C> static char test(typename C::mapped_type*);
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template<typename C> static char (&test(...))[2];
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public:
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static constexpr bool value = sizeof(test<T>(0)) == 1;
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};
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/// "equality" comparison for floating point numbers
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template<typename T>
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static bool approx(const T a, const T b)
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{
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return not (a > b or a < b);
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}
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}
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/*!
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@brief a class to store JSON values
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@tparam ObjectType type for JSON objects (@c std::map by default; will be used
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in @ref object_t)
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@tparam ArrayType type for JSON arrays (@c std::vector by default; will be used
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in @ref array_t)
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@tparam StringType type for JSON strings and object keys (@c std::string by
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default; will be used in @ref string_t)
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@tparam BooleanType type for JSON booleans (@c `bool` by default; will be used
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in @ref boolean_t)
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@tparam NumberIntegerType type for JSON integer numbers (@c `int64_t` by
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default; will be used in @ref number_integer_t)
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@tparam NumberFloatType type for JSON floating-point numbers (@c `double` by
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default; will be used in @ref number_float_t)
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@tparam AllocatorType type of the allocator to use (@c `std::allocator` by
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default)
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@requirement The class satisfies the following concept requirements:
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- Basic
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- [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible):
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JSON values can be default constructed. The result will be a JSON null value.
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- [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible):
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A JSON value can be constructed from an rvalue argument.
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- [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible):
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A JSON value can be copy-constructed from an lvalue expression.
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- [MoveAssignable](http://en.cppreference.com/w/cpp/concept/MoveAssignable):
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A JSON value van be assigned from an rvalue argument.
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- [CopyAssignable](http://en.cppreference.com/w/cpp/concept/CopyAssignable):
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A JSON value can be copy-assigned from an lvalue expression.
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- [Destructible](http://en.cppreference.com/w/cpp/concept/Destructible):
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JSON values can be destructed.
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- Layout
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- [StandardLayoutType](http://en.cppreference.com/w/cpp/concept/StandardLayoutType):
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JSON values have
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[standard layout](http://en.cppreference.com/w/cpp/language/data_members#Standard_layout):
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All non-static data members are private and standard layout types, the class
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has no virtual functions or (virtual) base classes.
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- Library-wide
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- [EqualityComparable](http://en.cppreference.com/w/cpp/concept/EqualityComparable):
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JSON values can be compared with `==`, see @ref
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operator==(const_reference,const_reference).
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- [LessThanComparable](http://en.cppreference.com/w/cpp/concept/LessThanComparable):
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JSON values can be compared with `<`, see @ref
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operator<(const_reference,const_reference).
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- [Swappable](http://en.cppreference.com/w/cpp/concept/Swappable):
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Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of
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other compatible types, using unqualified function call @ref swap().
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- [NullablePointer](http://en.cppreference.com/w/cpp/concept/NullablePointer):
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JSON values can be compared against `std::nullptr_t` objects which are used
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to model the `null` value.
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- Container
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- [Container](http://en.cppreference.com/w/cpp/concept/Container):
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JSON values can be used like STL containers and provide iterator access.
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- [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer);
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JSON values can be used like STL containers and provide reverse iterator
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access.
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@internal
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@note ObjectType trick from http://stackoverflow.com/a/9860911
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@endinternal
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@see RFC 7159 <http://rfc7159.net/rfc7159>
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@since version 1.0.0
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@nosubgrouping
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*/
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template <
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template<typename U, typename V, typename... Args> class ObjectType = std::map,
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template<typename U, typename... Args> class ArrayType = std::vector,
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class StringType = std::string,
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class BooleanType = bool,
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class NumberIntegerType = int64_t,
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class NumberFloatType = double,
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template<typename U> class AllocatorType = std::allocator
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>
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class basic_json
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{
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private:
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/// workaround type for MSVC
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using basic_json_t = basic_json<ObjectType,
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ArrayType,
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StringType,
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BooleanType,
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NumberIntegerType,
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NumberFloatType,
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AllocatorType>;
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public:
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/////////////////////
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// container types //
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/////////////////////
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/// @name container types
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/// @{
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/// the type of elements in a basic_json container
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using value_type = basic_json;
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/// the type of an element reference
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using reference = value_type&;
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/// the type of an element const reference
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using const_reference = const value_type&;
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/// a type to represent differences between iterators
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using difference_type = std::ptrdiff_t;
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/// a type to represent container sizes
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using size_type = std::size_t;
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/// the allocator type
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using allocator_type = AllocatorType<basic_json>;
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/// the type of an element pointer
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using pointer = typename std::allocator_traits<allocator_type>::pointer;
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/// the type of an element const pointer
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using const_pointer = typename std::allocator_traits<allocator_type>::const_pointer;
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// forward declaration
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template<typename Base> class json_reverse_iterator;
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/// an iterator for a basic_json container
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class iterator;
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/// a const iterator for a basic_json container
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class const_iterator;
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/// a reverse iterator for a basic_json container
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using reverse_iterator = json_reverse_iterator<typename basic_json::iterator>;
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/// a const reverse iterator for a basic_json container
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using const_reverse_iterator = json_reverse_iterator<typename basic_json::const_iterator>;
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/// @}
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/*!
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@brief returns the allocator associated with the container
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*/
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static allocator_type get_allocator()
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{
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return allocator_type();
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}
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///////////////////////////
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// JSON value data types //
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///////////////////////////
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/// @name JSON value data types
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/// @{
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/*!
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@brief a type for an object
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[RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows:
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> An object is an unordered collection of zero or more name/value pairs,
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> where a name is a string and a value is a string, number, boolean, null,
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> object, or array.
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To store objects in C++, a type is defined by the template parameters
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described below.
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@tparam ObjectType the container to store objects (e.g., `std::map` or
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`std::unordered_map`)
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@tparam StringType the type of the keys or names (e.g., `std::string`). The
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comparison function `std::less<StringType>` is used to order elements
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inside the container.
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@tparam AllocatorType the allocator to use for objects (e.g.,
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`std::allocator`)
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#### Default type
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With the default values for @a ObjectType (`std::map`), @a StringType
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(`std::string`), and @a AllocatorType (`std::allocator`), the default value
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for @a object_t is:
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@code {.cpp}
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std::map<
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std::string, // key_type
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basic_json, // value_type
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std::less<std::string>, // key_compare
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std::allocator<std::pair<const std::string, basic_json>> // allocator_type
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>
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@endcode
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#### Behavior
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The choice of @a object_t influences the behavior of the JSON class. With
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the default type, objects have the following behavior:
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- When all names are unique, objects will be interoperable in the sense
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that all software implementations receiving that object will agree on the
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name-value mappings.
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- When the names within an object are not unique, later stored name/value
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pairs overwrite previously stored name/value pairs, leaving the used
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names unique. For instance, `{"key": 1}` and `{"key": 2, "key": 1}` will
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be treated as equal and both stored as `{"key": 1}`.
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- Internally, name/value pairs are stored in lexicographical order of the
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names. Objects will also be serialized (see @ref dump) in this order. For
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instance, `{"b": 1, "a": 2}` and `{"a": 2, "b": 1}` will be stored and
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serialized as `{"a": 2, "b": 1}`.
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- When comparing objects, the order of the name/value pairs is irrelevant.
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This makes objects interoperable in the sense that they will not be
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affected by these differences. For instance, `{"b": 1, "a": 2}` and
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`{"a": 2, "b": 1}` will be treated as equal.
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#### Limits
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[RFC 7159](http://rfc7159.net/rfc7159) specifies:
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> An implementation may set limits on the maximum depth of nesting.
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In this class, the object's limit of nesting is not constraint explicitly.
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However, a maximum depth of nesting may be introduced by the compiler or
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runtime environment. A theoretical limit can be queried by calling the @ref
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max_size function of a JSON object.
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#### Storage
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Objects are stored as pointers in a @ref basic_json type. That is, for any
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access to object values, a pointer of type `object_t*` must be dereferenced.
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@sa @ref array_t -- type for an array value
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@since version 1.0.0
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*/
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using object_t = ObjectType<StringType,
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basic_json,
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std::less<StringType>,
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AllocatorType<std::pair<const StringType,
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basic_json>>>;
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/*!
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@brief a type for an array
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[RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows:
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> An array is an ordered sequence of zero or more values.
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To store objects in C++, a type is defined by the template parameters
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explained below.
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@tparam ArrayType container type to store arrays (e.g., `std::vector` or
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`std::list`)
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@tparam AllocatorType allocator to use for arrays (e.g., `std::allocator`)
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#### Default type
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With the default values for @a ArrayType (`std::vector`) and @a
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AllocatorType (`std::allocator`), the default value for @a array_t is:
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@code {.cpp}
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std::vector<
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basic_json, // value_type
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std::allocator<basic_json> // allocator_type
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>
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@endcode
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#### Limits
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[RFC 7159](http://rfc7159.net/rfc7159) specifies:
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> An implementation may set limits on the maximum depth of nesting.
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In this class, the array's limit of nesting is not constraint explicitly.
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However, a maximum depth of nesting may be introduced by the compiler or
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runtime environment. A theoretical limit can be queried by calling the @ref
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max_size function of a JSON array.
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#### Storage
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Arrays are stored as pointers in a @ref basic_json type. That is, for any
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access to array values, a pointer of type `array_t*` must be dereferenced.
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@sa @ref object_t -- type for an object value
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@since version 1.0.0
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*/
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using array_t = ArrayType<basic_json, AllocatorType<basic_json>>;
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/*!
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@brief a type for a string
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[RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows:
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> A string is a sequence of zero or more Unicode characters.
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To store objects in C++, a type is defined by the template parameter
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described below. Unicode values are split by the JSON class into byte-sized
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characters during deserialization.
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@tparam StringType the container to store strings (e.g., `std::string`).
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Note this container is used for keys/names in objects, see @ref object_t.
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#### Default type
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With the default values for @a StringType (`std::string`), the default
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value for @a string_t is:
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@code {.cpp}
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std::string
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@endcode
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#### String comparison
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[RFC 7159](http://rfc7159.net/rfc7159) states:
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> Software implementations are typically required to test names of object
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> members for equality. Implementations that transform the textual
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> representation into sequences of Unicode code units and then perform the
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> comparison numerically, code unit by code unit, are interoperable in the
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> sense that implementations will agree in all cases on equality or
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> inequality of two strings. For example, implementations that compare
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> strings with escaped characters unconverted may incorrectly find that
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> `"a\\b"` and `"a\u005Cb"` are not equal.
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This implementation is interoperable as it does compare strings code unit
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by code unit.
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#### Storage
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String values are stored as pointers in a @ref basic_json type. That is,
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for any access to string values, a pointer of type `string_t*` must be
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dereferenced.
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@since version 1.0.0
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*/
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using string_t = StringType;
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/*!
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@brief a type for a boolean
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|
[RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a
|
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type which differentiates the two literals `true` and `false`.
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To store objects in C++, a type is defined by the template parameter @a
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BooleanType which chooses the type to use.
|
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#### Default type
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With the default values for @a BooleanType (`bool`), the default value for
|
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@a boolean_t is:
|
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@code {.cpp}
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bool
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@endcode
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#### Storage
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Boolean values are stored directly inside a @ref basic_json type.
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@since version 1.0.0
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*/
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using boolean_t = BooleanType;
|
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|
|
/*!
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@brief a type for a number (integer)
|
|
|
|
[RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows:
|
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> The representation of numbers is similar to that used in most programming
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> languages. A number is represented in base 10 using decimal digits. It
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> contains an integer component that may be prefixed with an optional minus
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> sign, which may be followed by a fraction part and/or an exponent part.
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> Leading zeros are not allowed. (...) Numeric values that cannot be
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> represented in the grammar below (such as Infinity and NaN) are not
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> permitted.
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This description includes both integer and floating-point numbers. However,
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C++ allows more precise storage if it is known whether the number is an
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integer or a floating-point number. Therefore, two different types, @ref
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number_integer_t and @ref number_float_t are used.
|
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|
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To store integer numbers in C++, a type is defined by the template
|
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parameter @a NumberIntegerType which chooses the type to use.
|
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|
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#### Default type
|
|
|
|
With the default values for @a NumberIntegerType (`int64_t`), the default
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value for @a number_integer_t is:
|
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|
|
@code {.cpp}
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int64_t
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@endcode
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|
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#### Default behavior
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|
|
|
- The restrictions about leading zeros is not enforced in C++. Instead,
|
|
leading zeros in integer literals lead to an interpretation as octal
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number. Internally, the value will be stored as decimal number. For
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instance, the C++ integer literal `010` will be serialized to `8`. During
|
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deserialization, leading zeros yield an error.
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- Not-a-number (NaN) values will be serialized to `null`.
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|
|
#### Limits
|
|
|
|
[RFC 7159](http://rfc7159.net/rfc7159) specifies:
|
|
> An implementation may set limits on the range and precision of numbers.
|
|
|
|
When the default type is used, the maximal integer number that can be
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stored is `9223372036854775807` (INT64_MAX) and the minimal integer number
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that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers
|
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that are out of range will yield over/underflow when used in a constructor.
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During deserialization, too large or small integer numbers will be
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automatically be stored as @ref number_float_t.
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|
|
[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.
|
|
|
|
As this range is a subrange of the exactly supported range [INT64_MIN,
|
|
INT64_MAX], this class's integer type is interoperable.
|
|
|
|
#### Storage
|
|
|
|
Integer number values are stored directly inside a @ref basic_json type.
|
|
|
|
@sa @ref number_float_t -- type for number values (floating-point)
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
using number_integer_t = NumberIntegerType;
|
|
|
|
/*!
|
|
@brief a type for a number (floating-point)
|
|
|
|
[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.
|
|
|
|
This description includes both integer and floating-point numbers. However,
|
|
C++ allows more precise storage if it is known whether the number is an
|
|
integer or a floating-point number. Therefore, two different types, @ref
|
|
number_integer_t and @ref number_float_t are used.
|
|
|
|
To store floating-point numbers in C++, a type is defined by the template
|
|
parameter @a NumberFloatType which chooses the type to use.
|
|
|
|
#### Default type
|
|
|
|
With the default values for @a NumberFloatType (`double`), the default
|
|
value for @a number_float_t is:
|
|
|
|
@code {.cpp}
|
|
double
|
|
@endcode
|
|
|
|
#### Default behavior
|
|
|
|
- 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`.
|
|
|
|
#### Limits
|
|
|
|
[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.
|
|
|
|
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`.
|
|
|
|
#### Storage
|
|
|
|
Floating-point number values are stored directly inside a @ref basic_json
|
|
type.
|
|
|
|
@sa @ref number_integer_t -- type for number values (integer)
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
using number_float_t = NumberFloatType;
|
|
|
|
/// @}
|
|
|
|
|
|
///////////////////////////
|
|
// JSON type enumeration //
|
|
///////////////////////////
|
|
|
|
/*!
|
|
@brief the JSON type enumeration
|
|
|
|
This enumeration collects the different JSON types. It is internally used
|
|
to distinguish the stored values, and the functions @ref is_null(), @ref
|
|
is_object(), @ref is_array(), @ref is_string(), @ref is_boolean(), @ref
|
|
is_number(), and @ref is_discarded() rely on it.
|
|
|
|
@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 (integer)
|
|
number_float, ///< number value (floating-point)
|
|
discarded ///< discarded by the the parser callback function
|
|
};
|
|
|
|
|
|
private:
|
|
/// helper for exception-safe object creation
|
|
template<typename T, typename... Args>
|
|
static T* create(Args&& ... args)
|
|
{
|
|
AllocatorType<T> alloc;
|
|
auto deleter = [&](T * object)
|
|
{
|
|
alloc.deallocate(object, 1);
|
|
};
|
|
std::unique_ptr<T, decltype(deleter)> object(alloc.allocate(1), deleter);
|
|
alloc.construct(object.get(), std::forward<Args>(args)...);
|
|
return object.release();
|
|
}
|
|
|
|
////////////////////////
|
|
// JSON value storage //
|
|
////////////////////////
|
|
|
|
/*!
|
|
@brief a JSON value
|
|
|
|
The actual storage for a JSON value of the @ref basic_json class.
|
|
|
|
@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 (floating-point)
|
|
number_float_t number_float;
|
|
|
|
/// default constructor (for null values)
|
|
json_value() noexcept = 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 (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<object_t>();
|
|
break;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
array = create<array_t>();
|
|
break;
|
|
}
|
|
|
|
case value_t::string:
|
|
{
|
|
string = create<string_t>("");
|
|
break;
|
|
}
|
|
|
|
case value_t::boolean:
|
|
{
|
|
boolean = boolean_t(false);
|
|
break;
|
|
}
|
|
|
|
case value_t::number_integer:
|
|
{
|
|
number_integer = number_integer_t(0);
|
|
break;
|
|
}
|
|
|
|
case value_t::number_float:
|
|
{
|
|
number_float = number_float_t(0.0);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// constructor for strings
|
|
json_value(const string_t& value)
|
|
{
|
|
string = create<string_t>(value);
|
|
}
|
|
|
|
/// constructor for objects
|
|
json_value(const object_t& value)
|
|
{
|
|
object = create<object_t>(value);
|
|
}
|
|
|
|
/// constructor for arrays
|
|
json_value(const array_t& value)
|
|
{
|
|
array = create<array_t>(value);
|
|
}
|
|
};
|
|
|
|
|
|
public:
|
|
//////////////////////////
|
|
// JSON parser callback //
|
|
//////////////////////////
|
|
|
|
/*!
|
|
@brief JSON callback events
|
|
|
|
This enumeration lists the parser events that can trigger calling a
|
|
callback function of type @ref parser_callback_t during parsing.
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
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
|
|
};
|
|
|
|
/*!
|
|
@brief per-element parser callback type
|
|
|
|
With a parser callback function, the result of parsing a JSON text can be
|
|
influenced. When passed to @ref parse(std::istream&, parser_callback_t) or
|
|
@ref parse(const string_t&, 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.
|
|
|
|
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.
|
|
|
|
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
|
|
|
|
Discarding a value (i.e., returning `false`) has different effects
|
|
depending on the context in which function was called:
|
|
|
|
- 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.
|
|
|
|
@param[in] depth the depth of the recursion during parsing
|
|
|
|
@param[in] event an event of type parse_event_t indicating the context in
|
|
the callback function has been called
|
|
|
|
@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 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.
|
|
|
|
@sa @ref parse(std::istream&, parser_callback_t) or
|
|
@ref parse(const string_t&, parser_callback_t) for examples
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
using parser_callback_t = std::function<bool(int depth, parse_event_t event, basic_json& parsed)>;
|
|
|
|
|
|
//////////////////
|
|
// constructors //
|
|
//////////////////
|
|
|
|
/// @name constructors and destructors
|
|
/// @{
|
|
|
|
/*!
|
|
@brief create an empty value with a given type
|
|
|
|
Create an empty JSON value with a given type. The value will be default
|
|
initialized with an empty value which depends on the type:
|
|
|
|
Value type | initial value
|
|
----------- | -------------
|
|
null | `null`
|
|
boolean | `false`
|
|
string | `""`
|
|
number | `0`
|
|
object | `{}`
|
|
array | `[]`
|
|
|
|
@param[in] value_type the type of the value to create
|
|
|
|
@complexity Constant.
|
|
|
|
@throw std::bad_alloc if allocation for object, array, or string value
|
|
fails
|
|
|
|
@liveexample{The following code shows the constructor for different @ref
|
|
value_t values,basic_json__value_t}
|
|
|
|
@sa @ref basic_json(std::nullptr_t) -- create a `null` value
|
|
@sa @ref basic_json(boolean_t value) -- create a boolean value
|
|
@sa @ref basic_json(const string_t&) -- create a string value
|
|
@sa @ref basic_json(const object_t&) -- create a object value
|
|
@sa @ref basic_json(const array_t&) -- create a array value
|
|
@sa @ref basic_json(const number_float_t) -- create a number
|
|
(floating-point) value
|
|
@sa @ref basic_json(const number_integer_t) -- create a number (integer)
|
|
value
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(const value_t value_type)
|
|
: m_type(value_type), m_value(value_type)
|
|
{}
|
|
|
|
/*!
|
|
@brief create a null object (implicitly)
|
|
|
|
Create a `null` JSON value. This is the implicit version of the `null`
|
|
value constructor as it takes no parameters.
|
|
|
|
@complexity Constant.
|
|
|
|
@requirement This function satisfies the Container requirements:
|
|
- The complexity is constant.
|
|
- As postcondition, it holds: `basic_json().empty() == true`.
|
|
|
|
@liveexample{The following code shows the constructor for a `null` JSON
|
|
value.,basic_json}
|
|
|
|
@sa @ref basic_json(std::nullptr_t) -- create a `null` value
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json() noexcept = default;
|
|
|
|
/*!
|
|
@brief create a null object (explicitly)
|
|
|
|
Create a `null` JSON value. This is the explicitly version of the `null`
|
|
value constructor as it takes a null pointer as parameter. It allows to
|
|
create `null` values by explicitly assigning a @c nullptr to a JSON value.
|
|
The passed null pointer itself is not read -- it is only used to choose the
|
|
right constructor.
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The following code shows the constructor with null pointer
|
|
parameter.,basic_json__nullptr_t}
|
|
|
|
@sa @ref basic_json() -- default constructor (implicitly creating a `null`
|
|
value)
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(std::nullptr_t) noexcept
|
|
: basic_json(value_t::null)
|
|
{}
|
|
|
|
/*!
|
|
@brief create an object (explicit)
|
|
|
|
Create an object JSON value with a given content.
|
|
|
|
@param[in] val a value for the object
|
|
|
|
@complexity Linear in the size of the passed @a val.
|
|
|
|
@throw std::bad_alloc if allocation for object value fails
|
|
|
|
@liveexample{The following code shows the constructor with an @ref object_t
|
|
parameter.,basic_json__object_t}
|
|
|
|
@sa @ref basic_json(const CompatibleObjectType&) -- create an object value
|
|
from a compatible STL container
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(const object_t& val)
|
|
: m_type(value_t::object), m_value(val)
|
|
{}
|
|
|
|
/*!
|
|
@brief create an object (implicit)
|
|
|
|
Create an object JSON value with a given content. This constructor allows
|
|
any type that can be used to construct values of type @ref object_t.
|
|
Examples include the types `std::map` and `std::unordered_map`.
|
|
|
|
@tparam CompatibleObjectType an object type whose `key_type` and
|
|
`value_type` is compatible to @ref object_t
|
|
|
|
@param[in] val a value for the object
|
|
|
|
@complexity Linear in the size of the passed @a val.
|
|
|
|
@throw std::bad_alloc if allocation for object value fails
|
|
|
|
@liveexample{The following code shows the constructor with several
|
|
compatible object type parameters.,basic_json__CompatibleObjectType}
|
|
|
|
@sa @ref basic_json(const object_t&) -- create an object value
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template <class CompatibleObjectType, typename
|
|
std::enable_if<
|
|
std::is_constructible<typename object_t::key_type, typename CompatibleObjectType::key_type>::value and
|
|
std::is_constructible<basic_json, typename CompatibleObjectType::mapped_type>::value, int>::type
|
|
= 0>
|
|
basic_json(const CompatibleObjectType& val)
|
|
: m_type(value_t::object)
|
|
{
|
|
using std::begin;
|
|
using std::end;
|
|
m_value.object = create<object_t>(begin(val), end(val));
|
|
}
|
|
|
|
/*!
|
|
@brief create an array (explicit)
|
|
|
|
Create an array JSON value with a given content.
|
|
|
|
@param[in] val a value for the array
|
|
|
|
@complexity Linear in the size of the passed @a val.
|
|
|
|
@throw std::bad_alloc if allocation for array value fails
|
|
|
|
@liveexample{The following code shows the constructor with an @ref array_t
|
|
parameter.,basic_json__array_t}
|
|
|
|
@sa @ref basic_json(const CompatibleArrayType&) -- create an array value
|
|
from a compatible STL containers
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(const array_t& val)
|
|
: m_type(value_t::array), m_value(val)
|
|
{}
|
|
|
|
/*!
|
|
@brief create an array (implicit)
|
|
|
|
Create an array JSON value with a given content. This constructor allows
|
|
any type that can be used to construct values of type @ref array_t.
|
|
Examples include the types `std::vector`, `std::list`, and `std::set`.
|
|
|
|
@tparam CompatibleArrayType an object type whose `value_type` is compatible
|
|
to @ref array_t
|
|
|
|
@param[in] val a value for the array
|
|
|
|
@complexity Linear in the size of the passed @a val.
|
|
|
|
@throw std::bad_alloc if allocation for array value fails
|
|
|
|
@liveexample{The following code shows the constructor with several
|
|
compatible array type parameters.,basic_json__CompatibleArrayType}
|
|
|
|
@sa @ref basic_json(const array_t&) -- create an array value
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template <class CompatibleArrayType, typename
|
|
std::enable_if<
|
|
not std::is_same<CompatibleArrayType, typename basic_json_t::iterator>::value and
|
|
not std::is_same<CompatibleArrayType, typename basic_json_t::const_iterator>::value and
|
|
not std::is_same<CompatibleArrayType, typename basic_json_t::reverse_iterator>::value and
|
|
not std::is_same<CompatibleArrayType, typename basic_json_t::const_reverse_iterator>::value and
|
|
not std::is_same<CompatibleArrayType, typename array_t::iterator>::value and
|
|
not std::is_same<CompatibleArrayType, typename array_t::const_iterator>::value and
|
|
std::is_constructible<basic_json, typename CompatibleArrayType::value_type>::value, int>::type
|
|
= 0>
|
|
basic_json(const CompatibleArrayType& val)
|
|
: m_type(value_t::array)
|
|
{
|
|
using std::begin;
|
|
using std::end;
|
|
m_value.array = create<array_t>(begin(val), end(val));
|
|
}
|
|
|
|
/*!
|
|
@brief create a string (explicit)
|
|
|
|
Create an string JSON value with a given content.
|
|
|
|
@param[in] val a value for the string
|
|
|
|
@complexity Linear in the size of the passed @a val.
|
|
|
|
@throw std::bad_alloc if allocation for string value fails
|
|
|
|
@liveexample{The following code shows the constructor with an @ref string_t
|
|
parameter.,basic_json__string_t}
|
|
|
|
@sa @ref basic_json(const typename string_t::value_type*) -- create a
|
|
string value from a character pointer
|
|
@sa @ref basic_json(const CompatibleStringType&) -- create a string value
|
|
from a compatible string container
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(const string_t& val)
|
|
: m_type(value_t::string), m_value(val)
|
|
{}
|
|
|
|
/*!
|
|
@brief create a string (explicit)
|
|
|
|
Create a string JSON value with a given content.
|
|
|
|
@param[in] val a literal value for the string
|
|
|
|
@complexity Linear in the size of the passed @a val.
|
|
|
|
@throw std::bad_alloc if allocation for string value fails
|
|
|
|
@liveexample{The following code shows the constructor with string literal
|
|
parameter.,basic_json__string_t_value_type}
|
|
|
|
@sa @ref basic_json(const string_t&) -- create a string value
|
|
@sa @ref basic_json(const CompatibleStringType&) -- create a string value
|
|
from a compatible string container
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(const typename string_t::value_type* val)
|
|
: basic_json(string_t(val))
|
|
{}
|
|
|
|
/*!
|
|
@brief create a string (implicit)
|
|
|
|
Create a string JSON value with a given content.
|
|
|
|
@param[in] val a value for the string
|
|
|
|
@tparam CompatibleStringType an string type which is compatible to @ref
|
|
string_t
|
|
|
|
@complexity Linear in the size of the passed @a val.
|
|
|
|
@throw std::bad_alloc if allocation for string value fails
|
|
|
|
@liveexample{The following code shows the construction of a string value
|
|
from a compatible type.,basic_json__CompatibleStringType}
|
|
|
|
@sa @ref basic_json(const string_t&) -- create a string value
|
|
@sa @ref basic_json(const typename string_t::value_type*) -- create a
|
|
string value from a character pointer
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template <class CompatibleStringType, typename
|
|
std::enable_if<
|
|
std::is_constructible<string_t, CompatibleStringType>::value, int>::type
|
|
= 0>
|
|
basic_json(const CompatibleStringType& val)
|
|
: basic_json(string_t(val))
|
|
{}
|
|
|
|
/*!
|
|
@brief create a boolean (explicit)
|
|
|
|
Creates a JSON boolean type from a given value.
|
|
|
|
@param[in] val a boolean value to store
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below demonstrates boolean
|
|
values.,basic_json__boolean_t}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(boolean_t val)
|
|
: m_type(value_t::boolean), m_value(val)
|
|
{}
|
|
|
|
/*!
|
|
@brief create an integer number (explicit)
|
|
|
|
Create an integer number JSON value with a given content.
|
|
|
|
@tparam T helper type to compare number_integer_t and int (not visible in)
|
|
the interface.
|
|
|
|
@param[in] val an integer to create a JSON number from
|
|
|
|
@note This constructor would have the same signature as @ref
|
|
basic_json(const int value), so we need to switch this one off in case
|
|
number_integer_t is the same as int. This is done via the helper type @a T.
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows the construction of a JSON integer
|
|
number value.,basic_json__number_integer_t}
|
|
|
|
@sa @ref basic_json(const int) -- create a number value (integer)
|
|
@sa @ref basic_json(const CompatibleNumberIntegerType) -- create a number
|
|
value (integer) from a compatible number type
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template<typename T,
|
|
typename std::enable_if<
|
|
not (std::is_same<T, int>::value)
|
|
and std::is_same<T, number_integer_t>::value
|
|
, int>::type = 0>
|
|
basic_json(const number_integer_t val)
|
|
: m_type(value_t::number_integer), m_value(val)
|
|
{}
|
|
|
|
/*!
|
|
@brief create an integer number from an enum type (explicit)
|
|
|
|
Create an integer number JSON value with a given content.
|
|
|
|
@param[in] val an integer to create a JSON number from
|
|
|
|
@note This constructor allows to pass enums directly to a constructor. As
|
|
C++ has no way of specifying the type of an anonymous enum explicitly, we
|
|
can only rely on the fact that such values implicitly convert to int. As
|
|
int may already be the same type of number_integer_t, we may need to switch
|
|
off the constructor @ref basic_json(const number_integer_t).
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows the construction of a JSON integer
|
|
number value from an anonymous enum.,basic_json__const_int}
|
|
|
|
@sa @ref basic_json(const number_integer_t) -- create a number value
|
|
(integer)
|
|
@sa @ref basic_json(const CompatibleNumberIntegerType) -- create a number
|
|
value (integer) from a compatible number type
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(const int val)
|
|
: m_type(value_t::number_integer),
|
|
m_value(static_cast<number_integer_t>(val))
|
|
{}
|
|
|
|
/*!
|
|
@brief create an integer number (implicit)
|
|
|
|
Create an integer number JSON value with a given content. This constructor
|
|
allows any type that can be used to construct values of type @ref
|
|
number_integer_t. Examples may include the types `int`, `int32_t`, or
|
|
`short`.
|
|
|
|
@tparam CompatibleNumberIntegerType an integer type which is compatible to
|
|
@ref number_integer_t.
|
|
|
|
@param[in] val an integer to create a JSON number from
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows the construction of several JSON
|
|
integer number values from compatible
|
|
types.,basic_json__CompatibleIntegerNumberType}
|
|
|
|
@sa @ref basic_json(const number_integer_t) -- create a number value
|
|
(integer)
|
|
@sa @ref basic_json(const int) -- create a number value (integer)
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template<typename CompatibleNumberIntegerType, typename
|
|
std::enable_if<
|
|
std::is_constructible<number_integer_t, CompatibleNumberIntegerType>::value and
|
|
std::numeric_limits<CompatibleNumberIntegerType>::is_integer, CompatibleNumberIntegerType>::type
|
|
= 0>
|
|
basic_json(const CompatibleNumberIntegerType val) noexcept
|
|
: m_type(value_t::number_integer),
|
|
m_value(static_cast<number_integer_t>(val))
|
|
{}
|
|
|
|
/*!
|
|
@brief create a floating-point number (explicit)
|
|
|
|
Create a floating-point number JSON value with a given content.
|
|
|
|
@param[in] val a floating-point value to create a JSON number from
|
|
|
|
@note RFC 7159 <http://www.rfc-editor.org/rfc/rfc7159.txt>, section 6
|
|
disallows NaN values:
|
|
> Numeric values that cannot be represented in the grammar below (such
|
|
> as Infinity and NaN) are not permitted.
|
|
In case the parameter @a val is not a number, a JSON null value is
|
|
created instead.
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The following example creates several floating-point
|
|
values.,basic_json__number_float_t}
|
|
|
|
@sa @ref basic_json(const CompatibleNumberFloatType) -- create a number
|
|
value (floating-point) from a compatible number type
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(const number_float_t val)
|
|
: m_type(value_t::number_float), m_value(val)
|
|
{
|
|
// replace infinity and NAN by null
|
|
if (not std::isfinite(val))
|
|
{
|
|
m_type = value_t::null;
|
|
m_value = json_value();
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief create an floating-point number (implicit)
|
|
|
|
Create an floating-point number JSON value with a given content. This
|
|
constructor allows any type that can be used to construct values of type
|
|
@ref number_float_t. Examples may include the types `float`.
|
|
|
|
@tparam CompatibleNumberFloatType a floating-point type which is compatible
|
|
to @ref number_float_t.
|
|
|
|
@param[in] val a floating-point to create a JSON number from
|
|
|
|
@note RFC 7159 <http://www.rfc-editor.org/rfc/rfc7159.txt>, section 6
|
|
disallows NaN values:
|
|
> Numeric values that cannot be represented in the grammar below (such
|
|
> as Infinity and NaN) are not permitted.
|
|
In case the parameter @a val is not a number, a JSON null value is
|
|
created instead.
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows the construction of several JSON
|
|
floating-point number values from compatible
|
|
types.,basic_json__CompatibleNumberFloatType}
|
|
|
|
@sa @ref basic_json(const number_float_t) -- create a number value
|
|
(floating-point)
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template<typename CompatibleNumberFloatType, typename = typename
|
|
std::enable_if<
|
|
std::is_constructible<number_float_t, CompatibleNumberFloatType>::value and
|
|
std::is_floating_point<CompatibleNumberFloatType>::value>::type
|
|
>
|
|
basic_json(const CompatibleNumberFloatType val) noexcept
|
|
: basic_json(number_float_t(val))
|
|
{}
|
|
|
|
/*!
|
|
@brief create a container (array or object) from an initializer list
|
|
|
|
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:
|
|
|
|
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.
|
|
|
|
The rules aim to create the best fit between a C++ initializer list and
|
|
JSON values. The rationale is as follows:
|
|
|
|
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.
|
|
|
|
With the rules described above, the following JSON values cannot be
|
|
expressed by an initializer list:
|
|
|
|
- the empty array (`[]`): use @ref array(std::initializer_list<basic_json>)
|
|
with an empty initializer list in this case
|
|
- arrays whose elements satisfy rule 2: use @ref
|
|
array(std::initializer_list<basic_json>) 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(std::initializer_list<basic_json>) and
|
|
@ref object(std::initializer_list<basic_json>).
|
|
|
|
@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 std::domain_error 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; example: `"cannot create object from
|
|
initializer list"`
|
|
|
|
@complexity Linear in the size of the initializer list @a init.
|
|
|
|
@liveexample{The example below shows how JSON values are created from
|
|
initializer lists,basic_json__list_init_t}
|
|
|
|
@sa @ref array(std::initializer_list<basic_json>) -- create a JSON array
|
|
value from an initializer list
|
|
@sa @ref object(std::initializer_list<basic_json>) -- create a JSON object
|
|
value from an initializer list
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(std::initializer_list<basic_json> init,
|
|
bool type_deduction = true,
|
|
value_t manual_type = value_t::array)
|
|
{
|
|
// the initializer list could describe an object
|
|
bool is_an_object = true;
|
|
|
|
// check if each element is an array with two elements whose first
|
|
// element is a string
|
|
for (const auto& element : init)
|
|
{
|
|
if (not element.is_array() or element.size() != 2
|
|
or not element[0].is_string())
|
|
{
|
|
// we found an element that makes it impossible to use the
|
|
// initializer list as object
|
|
is_an_object = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// adjust type if type deduction is not wanted
|
|
if (not type_deduction)
|
|
{
|
|
// if array is wanted, do not create an object though possible
|
|
if (manual_type == value_t::array)
|
|
{
|
|
is_an_object = false;
|
|
}
|
|
|
|
// if object is wanted but impossible, throw an exception
|
|
if (manual_type == value_t::object and not is_an_object)
|
|
{
|
|
throw std::domain_error("cannot create object from initializer list");
|
|
}
|
|
}
|
|
|
|
if (is_an_object)
|
|
{
|
|
// the initializer list is a list of pairs -> create object
|
|
m_type = value_t::object;
|
|
m_value = value_t::object;
|
|
|
|
assert(m_value.object != nullptr);
|
|
|
|
for (auto& element : init)
|
|
{
|
|
m_value.object->emplace(std::move(*(element[0].m_value.string)), std::move(element[1]));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// the initializer list describes an array -> create array
|
|
m_type = value_t::array;
|
|
m_value.array = create<array_t>(std::move(init));
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@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<basic_json>, 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 @ref array
|
|
function.,array}
|
|
|
|
@sa @ref basic_json(std::initializer_list<basic_json>, bool, value_t) --
|
|
create a JSON value from an initializer list
|
|
@sa @ref object(std::initializer_list<basic_json>) -- create a JSON object
|
|
value from an initializer list
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
static basic_json array(std::initializer_list<basic_json> init =
|
|
std::initializer_list<basic_json>())
|
|
{
|
|
return basic_json(init, false, value_t::array);
|
|
}
|
|
|
|
/*!
|
|
@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<basic_json>), 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<basic_json>, bool, value_t).
|
|
|
|
@param[in] init initializer list to create an object from (optional)
|
|
|
|
@return JSON object value
|
|
|
|
@throw std::domain_error if @a init is not a pair whose first elements are
|
|
strings; thrown by
|
|
@ref basic_json(std::initializer_list<basic_json>, bool, value_t)
|
|
|
|
@complexity Linear in the size of @a init.
|
|
|
|
@liveexample{The following code shows an example for the @ref object
|
|
function.,object}
|
|
|
|
@sa @ref basic_json(std::initializer_list<basic_json>, bool, value_t) --
|
|
create a JSON value from an initializer list
|
|
@sa @ref array(std::initializer_list<basic_json>) -- create a JSON array
|
|
value from an initializer list
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
static basic_json object(std::initializer_list<basic_json> init =
|
|
std::initializer_list<basic_json>())
|
|
{
|
|
return basic_json(init, false, value_t::object);
|
|
}
|
|
|
|
/*!
|
|
@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. As postcondition,
|
|
`std::distance(begin(),end()) == cnt` holds.
|
|
|
|
@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.
|
|
|
|
@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
|
|
*/
|
|
basic_json(size_type cnt, const basic_json& val)
|
|
: m_type(value_t::array)
|
|
{
|
|
m_value.array = create<array_t>(cnt, val);
|
|
}
|
|
|
|
/*!
|
|
@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, std::out_of_range is thrown.
|
|
- In case of structured types (array, object), the constructor behaves
|
|
as similar versions for `std::vector`.
|
|
- In case of a null type, std::domain_error 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)
|
|
|
|
@throw std::domain_error if iterators are not compatible; that is, do not
|
|
belong to the same JSON value; example: `"iterators are not compatible"`
|
|
@throw std::out_of_range if iterators are for a primitive type (number,
|
|
boolean, or string) where an out of range error can be detected easily;
|
|
example: `"iterators out of range"`
|
|
@throw std::bad_alloc if allocation for object, array, or string fails
|
|
@throw std::domain_error if called with a null value; example: `"cannot use
|
|
construct with iterators from null"`
|
|
|
|
@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
|
|
*/
|
|
template <class InputIT, typename
|
|
std::enable_if<
|
|
std::is_same<InputIT, typename basic_json_t::iterator>::value or
|
|
std::is_same<InputIT, typename basic_json_t::const_iterator>::value
|
|
, int>::type
|
|
= 0>
|
|
basic_json(InputIT first, InputIT last) : m_type(first.m_object->m_type)
|
|
{
|
|
// make sure iterator fits the current value
|
|
if (first.m_object != last.m_object)
|
|
{
|
|
throw std::domain_error("iterators are not compatible");
|
|
}
|
|
|
|
// check if iterator range is complete for primitive values
|
|
switch (m_type)
|
|
{
|
|
case value_t::boolean:
|
|
case value_t::number_float:
|
|
case value_t::number_integer:
|
|
case value_t::string:
|
|
{
|
|
if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end())
|
|
{
|
|
throw std::out_of_range("iterators out of range");
|
|
}
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
|
|
switch (m_type)
|
|
{
|
|
case value_t::number_integer:
|
|
{
|
|
assert(first.m_object != nullptr);
|
|
m_value.number_integer = first.m_object->m_value.number_integer;
|
|
break;
|
|
}
|
|
|
|
case value_t::number_float:
|
|
{
|
|
assert(first.m_object != nullptr);
|
|
m_value.number_float = first.m_object->m_value.number_float;
|
|
break;
|
|
}
|
|
|
|
case value_t::boolean:
|
|
{
|
|
assert(first.m_object != nullptr);
|
|
m_value.boolean = first.m_object->m_value.boolean;
|
|
break;
|
|
}
|
|
|
|
case value_t::string:
|
|
{
|
|
assert(first.m_object != nullptr);
|
|
m_value = *first.m_object->m_value.string;
|
|
break;
|
|
}
|
|
|
|
case value_t::object:
|
|
{
|
|
m_value.object = create<object_t>(first.m_it.object_iterator, last.m_it.object_iterator);
|
|
break;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
m_value.array = create<array_t>(first.m_it.array_iterator, last.m_it.array_iterator);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
assert(first.m_object != nullptr);
|
|
throw std::domain_error("cannot use construct with iterators from " + first.m_object->type_name());
|
|
}
|
|
}
|
|
}
|
|
|
|
///////////////////////////////////////
|
|
// 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 satisfies the Container requirements:
|
|
- The complexity is linear.
|
|
- As postcondition, it holds: `other == basic_json(other)`.
|
|
|
|
@throw std::bad_alloc if allocation for object, array, or string fails.
|
|
|
|
@liveexample{The following code shows an example for the copy
|
|
constructor.,basic_json__basic_json}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
basic_json(const basic_json& other)
|
|
: m_type(other.m_type)
|
|
{
|
|
switch (m_type)
|
|
{
|
|
case value_t::object:
|
|
{
|
|
assert(other.m_value.object != nullptr);
|
|
m_value = *other.m_value.object;
|
|
break;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
assert(other.m_value.array != nullptr);
|
|
m_value = *other.m_value.array;
|
|
break;
|
|
}
|
|
|
|
case value_t::string:
|
|
{
|
|
assert(other.m_value.string != nullptr);
|
|
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_float:
|
|
{
|
|
m_value = other.m_value.number_float;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@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))
|
|
{
|
|
// invalidate payload
|
|
other.m_type = value_t::null;
|
|
other.m_value = {};
|
|
}
|
|
|
|
/*!
|
|
@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 satisfies the 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_t>::value and
|
|
std::is_nothrow_move_assignable<value_t>::value and
|
|
std::is_nothrow_move_constructible<json_value>::value and
|
|
std::is_nothrow_move_assignable<json_value>::value
|
|
)
|
|
{
|
|
using std::swap;
|
|
swap(m_type, other.m_type);
|
|
swap(m_value, other.m_value);
|
|
return *this;
|
|
}
|
|
|
|
/*!
|
|
@brief destructor
|
|
|
|
Destroys the JSON value and frees all allocated memory.
|
|
|
|
@complexity Linear.
|
|
|
|
@requirement This function satisfies the Container requirements:
|
|
- The complexity is linear.
|
|
- All stored elements are destroyed and all memory is freed.
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
~basic_json()
|
|
{
|
|
switch (m_type)
|
|
{
|
|
case value_t::object:
|
|
{
|
|
AllocatorType<object_t> alloc;
|
|
alloc.destroy(m_value.object);
|
|
alloc.deallocate(m_value.object, 1);
|
|
break;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
AllocatorType<array_t> alloc;
|
|
alloc.destroy(m_value.array);
|
|
alloc.deallocate(m_value.array, 1);
|
|
break;
|
|
}
|
|
|
|
case value_t::string:
|
|
{
|
|
AllocatorType<string_t> alloc;
|
|
alloc.destroy(m_value.string);
|
|
alloc.deallocate(m_value.string, 1);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
// all other types need no specific destructor
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// @}
|
|
|
|
public:
|
|
///////////////////////
|
|
// object inspection //
|
|
///////////////////////
|
|
|
|
/// @name object inspection
|
|
/// @{
|
|
|
|
/*!
|
|
@brief serialization
|
|
|
|
Serialization function for JSON values. The function tries to mimic
|
|
Python's @p json.dumps() function, and currently supports its @p 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
|
|
|
|
@return string containing the serialization of the JSON value
|
|
|
|
@complexity Linear.
|
|
|
|
@liveexample{The following example shows the effect of different @a indent
|
|
parameters to the result of the serialization.,dump}
|
|
|
|
@see https://docs.python.org/2/library/json.html#json.dump
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
string_t dump(const int indent = -1) const
|
|
{
|
|
std::stringstream ss;
|
|
|
|
if (indent >= 0)
|
|
{
|
|
dump(ss, true, static_cast<unsigned int>(indent));
|
|
}
|
|
else
|
|
{
|
|
dump(ss, false, 0);
|
|
}
|
|
|
|
return ss.str();
|
|
}
|
|
|
|
/*!
|
|
@brief return the type of the JSON value (explicit)
|
|
|
|
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.
|
|
|
|
@liveexample{The following code exemplifies @ref type() for all JSON
|
|
types.,type}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
value_t type() const noexcept
|
|
{
|
|
return m_type;
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@liveexample{The following code exemplifies @ref is_primitive for all JSON
|
|
types.,is_primitive}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_primitive() const noexcept
|
|
{
|
|
return is_null() or is_string() or is_boolean() or is_number();
|
|
}
|
|
|
|
/*!
|
|
@brief return whether type is structured
|
|
|
|
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.
|
|
|
|
@liveexample{The following code exemplifies @ref is_structured for all JSON
|
|
types.,is_structured}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_structured() const noexcept
|
|
{
|
|
return is_array() or is_object();
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@liveexample{The following code exemplifies @ref is_null for all JSON
|
|
types.,is_null}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_null() const noexcept
|
|
{
|
|
return m_type == value_t::null;
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@liveexample{The following code exemplifies @ref is_boolean for all JSON
|
|
types.,is_boolean}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_boolean() const noexcept
|
|
{
|
|
return m_type == value_t::boolean;
|
|
}
|
|
|
|
/*!
|
|
@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 or
|
|
floating-type), `false` otherwise.
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The following code exemplifies @ref is_number for all JSON
|
|
types.,is_number}
|
|
|
|
@sa @ref is_number_integer() -- check if value is an integer number
|
|
@sa @ref is_number_float() -- check if value is a floating-point number
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_number() const noexcept
|
|
{
|
|
return is_number_integer() or is_number_float();
|
|
}
|
|
|
|
/*!
|
|
@brief return whether value is an integer number
|
|
|
|
This function returns true iff the JSON value is an integer number. This
|
|
excludes floating-point values.
|
|
|
|
@return `true` if type is an integer number, `false` otherwise.
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The following code exemplifies @ref is_number_integer for all
|
|
JSON types.,is_number_integer}
|
|
|
|
@sa @ref is_number() -- check if value is a number
|
|
@sa @ref is_number_float() -- check if value is a floating-point number
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_number_integer() const noexcept
|
|
{
|
|
return m_type == value_t::number_integer;
|
|
}
|
|
|
|
/*!
|
|
@brief return whether value is a floating-point number
|
|
|
|
This function returns true iff the JSON value is a floating-point number.
|
|
This excludes integer values.
|
|
|
|
@return `true` if type is a floating-point number, `false` otherwise.
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The following code exemplifies @ref 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
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_number_float() const noexcept
|
|
{
|
|
return m_type == value_t::number_float;
|
|
}
|
|
|
|
/*!
|
|
@brief return whether value is an object
|
|
|
|
This function returns true iff the JSON value is an object.
|
|
|
|
@return `true` if type is object, `false` otherwise.
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The following code exemplifies @ref is_object for all JSON
|
|
types.,is_object}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_object() const noexcept
|
|
{
|
|
return m_type == value_t::object;
|
|
}
|
|
|
|
/*!
|
|
@brief return whether value is an array
|
|
|
|
This function returns true iff the JSON value is an array.
|
|
|
|
@return `true` if type is array, `false` otherwise.
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The following code exemplifies @ref is_array for all JSON
|
|
types.,is_array}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_array() const noexcept
|
|
{
|
|
return m_type == value_t::array;
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@liveexample{The following code exemplifies @ref is_string for all JSON
|
|
types.,is_string}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_string() const noexcept
|
|
{
|
|
return m_type == value_t::string;
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@liveexample{The following code exemplifies @ref is_discarded for all JSON
|
|
types.,is_discarded}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool is_discarded() const noexcept
|
|
{
|
|
return m_type == value_t::discarded;
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@liveexample{The following code exemplifies the value_t operator for all
|
|
JSON types.,operator__value_t}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
operator value_t() const noexcept
|
|
{
|
|
return m_type;
|
|
}
|
|
|
|
/// @}
|
|
|
|
private:
|
|
//////////////////
|
|
// value access //
|
|
//////////////////
|
|
|
|
/// get an object (explicit)
|
|
template <class T, typename
|
|
std::enable_if<
|
|
std::is_convertible<typename object_t::key_type, typename T::key_type>::value and
|
|
std::is_convertible<basic_json_t, typename T::mapped_type>::value
|
|
, int>::type = 0>
|
|
T get_impl(T*) const
|
|
{
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
return T(m_value.object->begin(), m_value.object->end());
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("type must be object, but is " + type_name());
|
|
}
|
|
}
|
|
|
|
/// get an object (explicit)
|
|
object_t get_impl(object_t*) const
|
|
{
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
return *(m_value.object);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("type must be object, but is " + type_name());
|
|
}
|
|
}
|
|
|
|
/// get an array (explicit)
|
|
template <class T, typename
|
|
std::enable_if<
|
|
std::is_convertible<basic_json_t, typename T::value_type>::value and
|
|
not std::is_same<basic_json_t, typename T::value_type>::value and
|
|
not std::is_arithmetic<T>::value and
|
|
not std::is_convertible<std::string, T>::value and
|
|
not has_mapped_type<T>::value
|
|
, int>::type = 0>
|
|
T get_impl(T*) const
|
|
{
|
|
if (is_array())
|
|
{
|
|
T to_vector;
|
|
assert(m_value.array != nullptr);
|
|
std::transform(m_value.array->begin(), m_value.array->end(),
|
|
std::inserter(to_vector, to_vector.end()), [](basic_json i)
|
|
{
|
|
return i.get<typename T::value_type>();
|
|
});
|
|
return to_vector;
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("type must be array, but is " + type_name());
|
|
}
|
|
}
|
|
|
|
/// get an array (explicit)
|
|
template <class T, typename
|
|
std::enable_if<
|
|
std::is_convertible<basic_json_t, T>::value and
|
|
not std::is_same<basic_json_t, T>::value
|
|
, int>::type = 0>
|
|
std::vector<T> get_impl(std::vector<T>*) const
|
|
{
|
|
if (is_array())
|
|
{
|
|
std::vector<T> to_vector;
|
|
assert(m_value.array != nullptr);
|
|
to_vector.reserve(m_value.array->size());
|
|
std::transform(m_value.array->begin(), m_value.array->end(),
|
|
std::inserter(to_vector, to_vector.end()), [](basic_json i)
|
|
{
|
|
return i.get<T>();
|
|
});
|
|
return to_vector;
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("type must be array, but is " + type_name());
|
|
}
|
|
}
|
|
|
|
/// get an array (explicit)
|
|
template <class T, typename
|
|
std::enable_if<
|
|
std::is_same<basic_json, typename T::value_type>::value and
|
|
not has_mapped_type<T>::value
|
|
, int>::type = 0>
|
|
T get_impl(T*) const
|
|
{
|
|
if (is_array())
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
return T(m_value.array->begin(), m_value.array->end());
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("type must be array, but is " + type_name());
|
|
}
|
|
}
|
|
|
|
/// get an array (explicit)
|
|
array_t get_impl(array_t*) const
|
|
{
|
|
if (is_array())
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
return *(m_value.array);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("type must be array, but is " + type_name());
|
|
}
|
|
}
|
|
|
|
/// get a string (explicit)
|
|
template <typename T, typename
|
|
std::enable_if<
|
|
std::is_convertible<string_t, T>::value
|
|
, int>::type = 0>
|
|
T get_impl(T*) const
|
|
{
|
|
if (is_string())
|
|
{
|
|
assert(m_value.string != nullptr);
|
|
return *m_value.string;
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("type must be string, but is " + type_name());
|
|
}
|
|
}
|
|
|
|
/// get a number (explicit)
|
|
template<typename T, typename
|
|
std::enable_if<
|
|
std::is_arithmetic<T>::value
|
|
, int>::type = 0>
|
|
T get_impl(T*) const
|
|
{
|
|
switch (m_type)
|
|
{
|
|
case value_t::number_integer:
|
|
{
|
|
return static_cast<T>(m_value.number_integer);
|
|
}
|
|
|
|
case value_t::number_float:
|
|
{
|
|
return static_cast<T>(m_value.number_float);
|
|
}
|
|
|
|
default:
|
|
{
|
|
throw std::domain_error("type must be number, but is " + type_name());
|
|
}
|
|
}
|
|
}
|
|
|
|
/// get a boolean (explicit)
|
|
boolean_t get_impl(boolean_t*) const
|
|
{
|
|
if (is_boolean())
|
|
{
|
|
return m_value.boolean;
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("type must be boolean, but is " + type_name());
|
|
}
|
|
}
|
|
|
|
/// get a pointer to the value (object)
|
|
object_t* get_impl_ptr(object_t*) noexcept
|
|
{
|
|
return is_object() ? m_value.object : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (object)
|
|
const object_t* get_impl_ptr(const object_t*) const noexcept
|
|
{
|
|
return is_object() ? m_value.object : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (array)
|
|
array_t* get_impl_ptr(array_t*) noexcept
|
|
{
|
|
return is_array() ? m_value.array : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (array)
|
|
const array_t* get_impl_ptr(const array_t*) const noexcept
|
|
{
|
|
return is_array() ? m_value.array : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (string)
|
|
string_t* get_impl_ptr(string_t*) noexcept
|
|
{
|
|
return is_string() ? m_value.string : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (string)
|
|
const string_t* get_impl_ptr(const string_t*) const noexcept
|
|
{
|
|
return is_string() ? m_value.string : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (boolean)
|
|
boolean_t* get_impl_ptr(boolean_t*) noexcept
|
|
{
|
|
return is_boolean() ? &m_value.boolean : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (boolean)
|
|
const boolean_t* get_impl_ptr(const boolean_t*) const noexcept
|
|
{
|
|
return is_boolean() ? &m_value.boolean : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (integer number)
|
|
number_integer_t* get_impl_ptr(number_integer_t*) noexcept
|
|
{
|
|
return is_number_integer() ? &m_value.number_integer : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (integer number)
|
|
const number_integer_t* get_impl_ptr(const number_integer_t*) const noexcept
|
|
{
|
|
return is_number_integer() ? &m_value.number_integer : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (floating-point number)
|
|
number_float_t* get_impl_ptr(number_float_t*) noexcept
|
|
{
|
|
return is_number_float() ? &m_value.number_float : nullptr;
|
|
}
|
|
|
|
/// get a pointer to the value (floating-point number)
|
|
const number_float_t* get_impl_ptr(const number_float_t*) const noexcept
|
|
{
|
|
return is_number_float() ? &m_value.number_float : nullptr;
|
|
}
|
|
|
|
public:
|
|
|
|
/// @name value access
|
|
/// @{
|
|
|
|
/*!
|
|
@brief get a value (explicit)
|
|
|
|
Explicit type conversion between the JSON value and a compatible value.
|
|
|
|
@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
|
|
|
|
@return copy of the JSON value, converted to type @a ValueType
|
|
|
|
@throw std::domain_error in case passed type @a ValueType is incompatible
|
|
to JSON; example: `"type must be object, but is null"`
|
|
|
|
@complexity Linear in the size of the JSON value.
|
|
|
|
@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<short>`\, (3) A JSON object can be converted to C++
|
|
associative containers such as `std::unordered_map<std::string\,
|
|
json>`.,get__ValueType_const}
|
|
|
|
@internal
|
|
The idea of using a casted null pointer to choose the correct
|
|
implementation is from <http://stackoverflow.com/a/8315197/266378>.
|
|
@endinternal
|
|
|
|
@sa @ref operator ValueType() const for implicit conversion
|
|
@sa @ref get() for pointer-member access
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template<typename ValueType, typename
|
|
std::enable_if<
|
|
not std::is_pointer<ValueType>::value
|
|
, int>::type = 0>
|
|
ValueType get() const
|
|
{
|
|
return get_impl(static_cast<ValueType*>(nullptr));
|
|
}
|
|
|
|
/*!
|
|
@brief get a pointer value (explicit)
|
|
|
|
Explicit pointer access to the internally stored JSON value. No copies are
|
|
made.
|
|
|
|
@warning The pointer becomes invalid if the underlying JSON object changes.
|
|
|
|
@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, or @ref
|
|
number_float_t.
|
|
|
|
@return pointer to the internally stored JSON value if the requested
|
|
pointer type @a PointerType fits to the JSON value; `nullptr` otherwise
|
|
|
|
@complexity Constant.
|
|
|
|
@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}
|
|
|
|
@sa @ref get_ptr() for explicit pointer-member access
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template<typename PointerType, typename
|
|
std::enable_if<
|
|
std::is_pointer<PointerType>::value
|
|
, int>::type = 0>
|
|
PointerType get() noexcept
|
|
{
|
|
// delegate the call to get_ptr
|
|
return get_ptr<PointerType>();
|
|
}
|
|
|
|
/*!
|
|
@brief get a pointer value (explicit)
|
|
@copydoc get()
|
|
*/
|
|
template<typename PointerType, typename
|
|
std::enable_if<
|
|
std::is_pointer<PointerType>::value
|
|
, int>::type = 0>
|
|
const PointerType get() const noexcept
|
|
{
|
|
// delegate the call to get_ptr
|
|
return get_ptr<PointerType>();
|
|
}
|
|
|
|
/*!
|
|
@brief get a pointer value (implicit)
|
|
|
|
Implicit pointer access to the internally stored JSON value. No copies are
|
|
made.
|
|
|
|
@warning Writing data to the pointee of the result yields an undefined
|
|
state.
|
|
|
|
@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, or @ref
|
|
number_float_t.
|
|
|
|
@return pointer to the internally stored JSON value if the requested
|
|
pointer type @a PointerType fits to the JSON value; `nullptr` otherwise
|
|
|
|
@complexity Constant.
|
|
|
|
@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}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template<typename PointerType, typename
|
|
std::enable_if<
|
|
std::is_pointer<PointerType>::value
|
|
, int>::type = 0>
|
|
PointerType get_ptr() noexcept
|
|
{
|
|
// delegate the call to get_impl_ptr<>()
|
|
return get_impl_ptr(static_cast<PointerType>(nullptr));
|
|
}
|
|
|
|
/*!
|
|
@brief get a pointer value (implicit)
|
|
@copydoc get_ptr()
|
|
*/
|
|
template<typename PointerType, typename
|
|
std::enable_if<
|
|
std::is_pointer<PointerType>::value
|
|
and std::is_const<typename std::remove_pointer<PointerType>::type>::value
|
|
, int>::type = 0>
|
|
const PointerType get_ptr() const noexcept
|
|
{
|
|
// delegate the call to get_impl_ptr<>() const
|
|
return get_impl_ptr(static_cast<const PointerType>(nullptr));
|
|
}
|
|
|
|
/*!
|
|
@brief get a value (implicit)
|
|
|
|
Implicit type conversion between the JSON value and a compatible value. The
|
|
call is realized by calling @ref get() const.
|
|
|
|
@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`.
|
|
|
|
@return copy of the JSON value, converted to type @a ValueType
|
|
|
|
@throw std::domain_error in case passed type @a ValueType is incompatible
|
|
to JSON, thrown by @ref get() const
|
|
|
|
@complexity Linear in the size of the JSON value.
|
|
|
|
@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<short>`\, (3) A JSON object can be converted to C++
|
|
associative containers such as `std::unordered_map<std::string\,
|
|
json>`.,operator__ValueType}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template<typename ValueType, typename
|
|
std::enable_if<
|
|
not std::is_pointer<ValueType>::value
|
|
and not std::is_same<ValueType, typename string_t::value_type>::value
|
|
and not std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>::value
|
|
, int>::type = 0>
|
|
operator ValueType() const
|
|
{
|
|
// delegate the call to get<>() const
|
|
return get<ValueType>();
|
|
}
|
|
|
|
/// @}
|
|
|
|
|
|
////////////////////
|
|
// element access //
|
|
////////////////////
|
|
|
|
/// @name element access
|
|
/// @{
|
|
|
|
/*!
|
|
@brief access specified array element with bounds checking
|
|
|
|
Returns a reference to the element at specified location @a idx, with
|
|
bounds checking.
|
|
|
|
@param[in] idx index of the element to access
|
|
|
|
@return reference to the element at index @a idx
|
|
|
|
@throw std::domain_error if the JSON value is not an array; example:
|
|
`"cannot use at() with string"`
|
|
@throw std::out_of_range if the index @a idx is out of range of the array;
|
|
that is, `idx >= size()`; example: `"array index 7 is out of range"`
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows how array elements can be read and
|
|
written using at.,at__size_type}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
reference at(size_type idx)
|
|
{
|
|
// at only works for arrays
|
|
if (is_array())
|
|
{
|
|
try
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
return m_value.array->at(idx);
|
|
}
|
|
catch (std::out_of_range&)
|
|
{
|
|
// create better exception explanation
|
|
throw std::out_of_range("array index " + std::to_string(idx) + " is out of range");
|
|
}
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use at() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@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 std::domain_error if the JSON value is not an array; example:
|
|
`"cannot use at() with string"`
|
|
@throw std::out_of_range if the index @a idx is out of range of the array;
|
|
that is, `idx >= size()`; example: `"array index 7 is out of range"`
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows how array elements can be read using
|
|
at.,at__size_type_const}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
const_reference at(size_type idx) const
|
|
{
|
|
// at only works for arrays
|
|
if (is_array())
|
|
{
|
|
try
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
return m_value.array->at(idx);
|
|
}
|
|
catch (std::out_of_range&)
|
|
{
|
|
// create better exception explanation
|
|
throw std::out_of_range("array index " + std::to_string(idx) + " is out of range");
|
|
}
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use at() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief access specified object element with bounds checking
|
|
|
|
Returns a reference to the element at with specified key @a key, with
|
|
bounds checking.
|
|
|
|
@param[in] key key of the element to access
|
|
|
|
@return reference to the element at key @a key
|
|
|
|
@throw std::domain_error if the JSON value is not an object; example:
|
|
`"cannot use at() with boolean"`
|
|
@throw std::out_of_range if the key @a key is is not stored in the object;
|
|
that is, `find(key) == end()`; example: `"key "the fast" not found"`
|
|
|
|
@complexity Logarithmic in the size of the container.
|
|
|
|
@liveexample{The example below shows how object elements can be read and
|
|
written using at.,at__object_t_key_type}
|
|
|
|
@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
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
reference at(const typename object_t::key_type& key)
|
|
{
|
|
// at only works for objects
|
|
if (is_object())
|
|
{
|
|
try
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
return m_value.object->at(key);
|
|
}
|
|
catch (std::out_of_range&)
|
|
{
|
|
// create better exception explanation
|
|
throw std::out_of_range("key '" + key + "' not found");
|
|
}
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use at() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief access specified object element with bounds checking
|
|
|
|
Returns a const reference to the element at with specified key @a key, with
|
|
bounds checking.
|
|
|
|
@param[in] key key of the element to access
|
|
|
|
@return const reference to the element at key @a key
|
|
|
|
@throw std::domain_error if the JSON value is not an object; example:
|
|
`"cannot use at() with boolean"`
|
|
@throw std::out_of_range if the key @a key is is not stored in the object;
|
|
that is, `find(key) == end()`; example: `"key "the fast" not found"`
|
|
|
|
@complexity Logarithmic in the size of the container.
|
|
|
|
@liveexample{The example below shows how object elements can be read using
|
|
at.,at__object_t_key_type_const}
|
|
|
|
@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
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
const_reference at(const typename object_t::key_type& key) const
|
|
{
|
|
// at only works for objects
|
|
if (is_object())
|
|
{
|
|
try
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
return m_value.object->at(key);
|
|
}
|
|
catch (std::out_of_range&)
|
|
{
|
|
// create better exception explanation
|
|
throw std::out_of_range("key '" + key + "' not found");
|
|
}
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use at() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief access specified array element
|
|
|
|
Returns a reference to the element at specified location @a idx.
|
|
|
|
@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] idx index of the element to access
|
|
|
|
@return reference to the element at index @a idx
|
|
|
|
@throw std::domain_error if JSON is not an array or null; example: `"cannot
|
|
use operator[] with null"`
|
|
|
|
@complexity Constant if @a idx is in the range of the array. Otherwise
|
|
linear in `idx - size()`.
|
|
|
|
@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
|
|
*/
|
|
reference operator[](size_type idx)
|
|
{
|
|
// implicitly convert null to object
|
|
if (is_null())
|
|
{
|
|
m_type = value_t::array;
|
|
m_value.array = create<array_t>();
|
|
}
|
|
|
|
// [] only works for arrays
|
|
if (is_array())
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
for (size_t i = m_value.array->size(); i <= idx; ++i)
|
|
{
|
|
m_value.array->push_back(basic_json());
|
|
}
|
|
|
|
return m_value.array->operator[](idx);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use operator[] with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief access specified array element
|
|
|
|
Returns a const reference to the element at specified location @a idx.
|
|
|
|
@param[in] idx index of the element to access
|
|
|
|
@return const reference to the element at index @a idx
|
|
|
|
@throw std::domain_error if JSON is not an array; example: `"cannot use
|
|
operator[] with null"`
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows how array elements can be read using
|
|
the [] operator.,operatorarray__size_type_const}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
const_reference operator[](size_type idx) const
|
|
{
|
|
// at only works for arrays
|
|
if (is_array())
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
return m_value.array->operator[](idx);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use operator[] with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief access specified object element
|
|
|
|
Returns a reference to the element at with specified key @a key.
|
|
|
|
@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] key key of the element to access
|
|
|
|
@return reference to the element at key @a key
|
|
|
|
@throw std::domain_error if JSON is not an object or null; example:
|
|
`"cannot use operator[] with null"`
|
|
|
|
@complexity Logarithmic in the size of the container.
|
|
|
|
@liveexample{The example below shows how object elements can be read and
|
|
written using the [] operator.,operatorarray__key_type}
|
|
|
|
@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
|
|
*/
|
|
reference operator[](const typename object_t::key_type& key)
|
|
{
|
|
// implicitly convert null to object
|
|
if (is_null())
|
|
{
|
|
m_type = value_t::object;
|
|
m_value.object = create<object_t>();
|
|
}
|
|
|
|
// [] only works for objects
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
return m_value.object->operator[](key);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use operator[] with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@warning If the element with key @a key does not exist, the behavior is
|
|
undefined.
|
|
|
|
@param[in] key key of the element to access
|
|
|
|
@return const reference to the element at key @a key
|
|
|
|
@throw std::domain_error if JSON is not an object; example: `"cannot use
|
|
operator[] with null"`
|
|
|
|
@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}
|
|
|
|
@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
|
|
*/
|
|
const_reference operator[](const typename object_t::key_type& key) const
|
|
{
|
|
// [] only works for objects
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
assert(m_value.object->find(key) != m_value.object->end());
|
|
return m_value.object->find(key)->second;
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use operator[] with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief access specified object element
|
|
|
|
Returns a reference to the element at with specified key @a key.
|
|
|
|
@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.
|
|
|
|
@note This function is required for compatibility reasons with Clang.
|
|
|
|
@param[in] key key of the element to access
|
|
|
|
@return reference to the element at key @a key
|
|
|
|
@throw std::domain_error if JSON is not an object or null; example:
|
|
`"cannot use operator[] with null"`
|
|
|
|
@complexity Logarithmic in the size of the container.
|
|
|
|
@liveexample{The example below shows how object elements can be read and
|
|
written using the [] operator.,operatorarray__key_type}
|
|
|
|
@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<typename T, std::size_t n>
|
|
reference operator[](const T (&key)[n])
|
|
{
|
|
// implicitly convert null to object
|
|
if (is_null())
|
|
{
|
|
m_type = value_t::object;
|
|
m_value = value_t::object;
|
|
}
|
|
|
|
// at only works for objects
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
return m_value.object->operator[](key);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use operator[] with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@warning If the element with key @a key does not exist, the behavior is
|
|
undefined.
|
|
|
|
@note This function is required for compatibility reasons with Clang.
|
|
|
|
@param[in] key key of the element to access
|
|
|
|
@return const reference to the element at key @a key
|
|
|
|
@throw std::domain_error if JSON is not an object; example: `"cannot use
|
|
operator[] with null"`
|
|
|
|
@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}
|
|
|
|
@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<typename T, std::size_t n>
|
|
const_reference operator[](const T (&key)[n]) const
|
|
{
|
|
// at only works for objects
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
assert(m_value.object->find(key) != m_value.object->end());
|
|
return m_value.object->find(key)->second;
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use operator[] with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief access specified object element with default 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.
|
|
|
|
The function is basically equivalent to executing
|
|
@code {.cpp}
|
|
try {
|
|
return at(key);
|
|
} catch(std::out_of_range) {
|
|
return default_value;
|
|
}
|
|
@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.
|
|
|
|
@return copy of the element at key @a key or @a default_value if @a key
|
|
is not found
|
|
|
|
@throw std::domain_error if JSON is not an object; example: `"cannot use
|
|
value() with null"`
|
|
|
|
@complexity Logarithmic in the size of the container.
|
|
|
|
@liveexample{The example below shows how object elements can be queried
|
|
with a default value.,basic_json__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
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template <class ValueType, typename
|
|
std::enable_if<
|
|
std::is_convertible<basic_json_t, ValueType>::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;
|
|
}
|
|
else
|
|
{
|
|
return default_value;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use value() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief overload for a default value of type const char*
|
|
@copydoc basic_json::value()
|
|
*/
|
|
string_t value(const typename object_t::key_type& key, const char* default_value) const
|
|
{
|
|
return value(key, string_t(default_value));
|
|
}
|
|
|
|
/*!
|
|
@brief access the first element
|
|
|
|
Returns a reference to the first element in the container. For a JSON
|
|
container `c`, the expression `c.front()` is equivalent to `*c.begin()`.
|
|
|
|
@return In case of a structured type (array or object), a reference to the
|
|
first element is returned. In cast of number, string, or boolean values, a
|
|
reference to the value is returned.
|
|
|
|
@complexity Constant.
|
|
|
|
@note Calling `front` on an empty container is undefined.
|
|
|
|
@throw std::out_of_range when called on null value
|
|
|
|
@liveexample{The following code shows an example for @ref front.,front}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
reference front()
|
|
{
|
|
return *begin();
|
|
}
|
|
|
|
/*!
|
|
@copydoc basic_json::front()
|
|
*/
|
|
const_reference front() const
|
|
{
|
|
return *cbegin();
|
|
}
|
|
|
|
/*!
|
|
@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 `{ auto tmp =
|
|
c.end(); --tmp; return *tmp; }`.
|
|
|
|
@return In case of a structured type (array or object), a reference to the
|
|
last element is returned. In cast of number, string, or boolean values, a
|
|
reference to the value is returned.
|
|
|
|
@complexity Constant.
|
|
|
|
@note Calling `back` on an empty container is undefined.
|
|
|
|
@throw std::out_of_range when called on null value.
|
|
|
|
@liveexample{The following code shows an example for @ref back.,back}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
reference back()
|
|
{
|
|
auto tmp = end();
|
|
--tmp;
|
|
return *tmp;
|
|
}
|
|
|
|
/*!
|
|
@copydoc basic_json::back()
|
|
*/
|
|
const_reference back() const
|
|
{
|
|
auto tmp = cend();
|
|
--tmp;
|
|
return *tmp;
|
|
}
|
|
|
|
/*!
|
|
@brief remove element given an iterator
|
|
|
|
Removes the element specified by iterator @a pos. Invalidates iterators and
|
|
references at or after the point of the erase, including the end()
|
|
iterator. 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.
|
|
|
|
@tparam InteratorType an @ref iterator or @ref const_iterator
|
|
|
|
@throw std::domain_error if called on a `null` value; example: `"cannot use
|
|
erase() with null"`
|
|
@throw std::domain_error if called on an iterator which does not belong to
|
|
the current JSON value; example: `"iterator does not fit current value"`
|
|
@throw std::out_of_range if called on a primitive type with invalid
|
|
iterator (i.e., any iterator which is not end()); example: `"iterator out
|
|
of range"`
|
|
|
|
@complexity The complexity depends on the type:
|
|
- objects: amortized constant
|
|
- arrays: linear in distance between pos and the end of the container
|
|
- strings: linear in the length of the string
|
|
- other types: constant
|
|
|
|
@liveexample{The example shows the result of erase for different JSON
|
|
types.,erase__IteratorType}
|
|
|
|
@sa @ref erase(InteratorType, InteratorType) -- 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
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template <class InteratorType, typename
|
|
std::enable_if<
|
|
std::is_same<InteratorType, typename basic_json_t::iterator>::value or
|
|
std::is_same<InteratorType, typename basic_json_t::const_iterator>::value
|
|
, int>::type
|
|
= 0>
|
|
InteratorType erase(InteratorType pos)
|
|
{
|
|
// make sure iterator fits the current value
|
|
if (this != pos.m_object)
|
|
{
|
|
throw std::domain_error("iterator does not fit current value");
|
|
}
|
|
|
|
InteratorType result = end();
|
|
|
|
switch (m_type)
|
|
{
|
|
case value_t::boolean:
|
|
case value_t::number_float:
|
|
case value_t::number_integer:
|
|
case value_t::string:
|
|
{
|
|
if (not pos.m_it.primitive_iterator.is_begin())
|
|
{
|
|
throw std::out_of_range("iterator out of range");
|
|
}
|
|
|
|
if (is_string())
|
|
{
|
|
delete m_value.string;
|
|
m_value.string = nullptr;
|
|
}
|
|
|
|
m_type = value_t::null;
|
|
break;
|
|
}
|
|
|
|
case value_t::object:
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator);
|
|
break;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
throw std::domain_error("cannot use erase() with " + type_name());
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief remove elements given an iterator range
|
|
|
|
Removes the element specified by the range `[first; last)`. Invalidates
|
|
iterators and references at or after the point of the erase, including the
|
|
end() iterator. The iterator @a first does not need to be dereferenceable
|
|
if `first == last`: erasing an empty range is a no-op.
|
|
|
|
If called on a primitive type other than null, the resulting JSON value
|
|
will be `null`.
|
|
|
|
@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.
|
|
|
|
@tparam InteratorType an @ref iterator or @ref const_iterator
|
|
|
|
@throw std::domain_error if called on a `null` value; example: `"cannot use
|
|
erase() with null"`
|
|
@throw std::domain_error if called on iterators which does not belong to
|
|
the current JSON value; example: `"iterators do not fit current value"`
|
|
@throw std::out_of_range if called on a primitive type with invalid
|
|
iterators (i.e., if `first != begin()` and `last != end()`); example:
|
|
`"iterators out of range"`
|
|
|
|
@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
|
|
|
|
@liveexample{The example shows the result of erase for different JSON
|
|
types.,erase__IteratorType_IteratorType}
|
|
|
|
@sa @ref erase(InteratorType) -- 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
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template <class InteratorType, typename
|
|
std::enable_if<
|
|
std::is_same<InteratorType, typename basic_json_t::iterator>::value or
|
|
std::is_same<InteratorType, typename basic_json_t::const_iterator>::value
|
|
, int>::type
|
|
= 0>
|
|
InteratorType erase(InteratorType first, InteratorType last)
|
|
{
|
|
// make sure iterator fits the current value
|
|
if (this != first.m_object or this != last.m_object)
|
|
{
|
|
throw std::domain_error("iterators do not fit current value");
|
|
}
|
|
|
|
InteratorType result = end();
|
|
|
|
switch (m_type)
|
|
{
|
|
case value_t::boolean:
|
|
case value_t::number_float:
|
|
case value_t::number_integer:
|
|
case value_t::string:
|
|
{
|
|
if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end())
|
|
{
|
|
throw std::out_of_range("iterators out of range");
|
|
}
|
|
|
|
if (is_string())
|
|
{
|
|
delete m_value.string;
|
|
m_value.string = nullptr;
|
|
}
|
|
|
|
m_type = value_t::null;
|
|
break;
|
|
}
|
|
|
|
case value_t::object:
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator,
|
|
last.m_it.object_iterator);
|
|
break;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator,
|
|
last.m_it.array_iterator);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
throw std::domain_error("cannot use erase() with " + type_name());
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief remove element from a JSON object given a key
|
|
|
|
Removes elements from a JSON object with the key value @a key.
|
|
|
|
@param[in] key value of the elements to remove
|
|
|
|
@return Number of elements removed. 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).
|
|
|
|
@throw std::domain_error when called on a type other than JSON object;
|
|
example: `"cannot use erase() with null"`
|
|
|
|
@complexity `log(size()) + count(key)`
|
|
|
|
@liveexample{The example shows the effect of erase.,erase__key_type}
|
|
|
|
@sa @ref erase(InteratorType) -- removes the element at a given position
|
|
@sa @ref erase(InteratorType, InteratorType) -- removes the elements in the
|
|
given range
|
|
@sa @ref erase(const size_type) -- removes the element from an array at the
|
|
given index
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
size_type erase(const typename object_t::key_type& key)
|
|
{
|
|
// this erase only works for objects
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
return m_value.object->erase(key);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use erase() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief remove element from a JSON array given an index
|
|
|
|
Removes element from a JSON array at the index @a idx.
|
|
|
|
@param[in] idx index of the element to remove
|
|
|
|
@throw std::domain_error when called on a type other than JSON array;
|
|
example: `"cannot use erase() with null"`
|
|
@throw std::out_of_range when `idx >= size()`; example: `"index out of
|
|
range"`
|
|
|
|
@complexity Linear in distance between @a idx and the end of the container.
|
|
|
|
@liveexample{The example shows the effect of erase.,erase__size_type}
|
|
|
|
@sa @ref erase(InteratorType) -- removes the element at a given position
|
|
@sa @ref erase(InteratorType, InteratorType) -- 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
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
void erase(const size_type idx)
|
|
{
|
|
// this erase only works for arrays
|
|
if (is_array())
|
|
{
|
|
if (idx >= size())
|
|
{
|
|
throw std::out_of_range("index out of range");
|
|
}
|
|
|
|
assert(m_value.array != nullptr);
|
|
m_value.array->erase(m_value.array->begin() + static_cast<difference_type>(idx));
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use erase() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief find an element in a JSON object
|
|
|
|
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.
|
|
|
|
@param[in] key key value of the element to search for
|
|
|
|
@return Iterator to an element with key equivalent to @a key. If no such
|
|
element is found, past-the-end (see end()) iterator is returned.
|
|
|
|
@complexity Logarithmic in the size of the JSON object.
|
|
|
|
@liveexample{The example shows how find is used.,find__key_type}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
iterator find(typename object_t::key_type key)
|
|
{
|
|
auto result = end();
|
|
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
result.m_it.object_iterator = m_value.object->find(key);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@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();
|
|
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
result.m_it.object_iterator = m_value.object->find(key);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@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).
|
|
|
|
@param[in] key key value of the element to count
|
|
|
|
@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.
|
|
|
|
@liveexample{The example shows how count is used.,count}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
size_type count(typename object_t::key_type key) const
|
|
{
|
|
// return 0 for all nonobject types
|
|
assert(not is_object() or m_value.object != nullptr);
|
|
return is_object() ? m_value.object->count(key) : 0;
|
|
}
|
|
|
|
/// @}
|
|
|
|
|
|
///////////////
|
|
// iterators //
|
|
///////////////
|
|
|
|
/// @name iterators
|
|
/// @{
|
|
|
|
/*!
|
|
@brief returns an iterator to the first element
|
|
|
|
Returns an iterator to the first element.
|
|
|
|
@image html range-begin-end.svg "Illustration from cppreference.com"
|
|
|
|
@return iterator to the first element
|
|
|
|
@complexity Constant.
|
|
|
|
@requirement This function satisfies the Container requirements:
|
|
- The complexity is constant.
|
|
|
|
@liveexample{The following code shows an example for @ref begin.,begin}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
iterator begin()
|
|
{
|
|
iterator result(this);
|
|
result.set_begin();
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@copydoc basic_json::cbegin()
|
|
*/
|
|
const_iterator begin() const
|
|
{
|
|
return cbegin();
|
|
}
|
|
|
|
/*!
|
|
@brief returns a const iterator to the first element
|
|
|
|
Returns a const iterator to the first element.
|
|
|
|
@image html range-begin-end.svg "Illustration from cppreference.com"
|
|
|
|
@return const iterator to the first element
|
|
|
|
@complexity Constant.
|
|
|
|
@requirement This function satisfies the Container requirements:
|
|
- The complexity is constant.
|
|
- Has the semantics of `const_cast<const basic_json&>(*this).begin()`.
|
|
|
|
@liveexample{The following code shows an example for @ref cbegin.,cbegin}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
const_iterator cbegin() const
|
|
{
|
|
const_iterator result(this);
|
|
result.set_begin();
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief returns an iterator to one past the last element
|
|
|
|
Returns an iterator to one past the last element.
|
|
|
|
@image html range-begin-end.svg "Illustration from cppreference.com"
|
|
|
|
@return iterator one past the last element
|
|
|
|
@complexity Constant.
|
|
|
|
@requirement This function satisfies the Container requirements:
|
|
- The complexity is constant.
|
|
|
|
@liveexample{The following code shows an example for @ref end.,end}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
iterator end()
|
|
{
|
|
iterator result(this);
|
|
result.set_end();
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@copydoc basic_json::cend()
|
|
*/
|
|
const_iterator end() const
|
|
{
|
|
return cend();
|
|
}
|
|
|
|
/*!
|
|
@brief returns a const iterator to one past the last element
|
|
|
|
Returns a const iterator to one past the last element.
|
|
|
|
@image html range-begin-end.svg "Illustration from cppreference.com"
|
|
|
|
@return const iterator one past the last element
|
|
|
|
@complexity Constant.
|
|
|
|
@requirement This function satisfies the Container requirements:
|
|
- The complexity is constant.
|
|
- Has the semantics of `const_cast<const basic_json&>(*this).end()`.
|
|
|
|
@liveexample{The following code shows an example for @ref cend.,cend}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
const_iterator cend() const
|
|
{
|
|
const_iterator result(this);
|
|
result.set_end();
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief returns an iterator to the reverse-beginning
|
|
|
|
Returns an iterator to the reverse-beginning; that is, the last element.
|
|
|
|
@image html range-rbegin-rend.svg "Illustration from cppreference.com"
|
|
|
|
@complexity Constant.
|
|
|
|
@requirement This function satisfies the ReversibleContainer requirements:
|
|
- The complexity is constant.
|
|
- Has the semantics of `reverse_iterator(end())`.
|
|
|
|
@liveexample{The following code shows an example for @ref rbegin.,rbegin}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
reverse_iterator rbegin()
|
|
{
|
|
return reverse_iterator(end());
|
|
}
|
|
|
|
/*!
|
|
@copydoc basic_json::crbegin()
|
|
*/
|
|
const_reverse_iterator rbegin() const
|
|
{
|
|
return crbegin();
|
|
}
|
|
|
|
/*!
|
|
@brief returns an iterator to the reverse-end
|
|
|
|
Returns an iterator to the reverse-end; that is, one before the first
|
|
element.
|
|
|
|
@image html range-rbegin-rend.svg "Illustration from cppreference.com"
|
|
|
|
@complexity Constant.
|
|
|
|
@requirement This function satisfies the ReversibleContainer requirements:
|
|
- The complexity is constant.
|
|
- Has the semantics of `reverse_iterator(begin())`.
|
|
|
|
@liveexample{The following code shows an example for @ref rend.,rend}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
reverse_iterator rend()
|
|
{
|
|
return reverse_iterator(begin());
|
|
}
|
|
|
|
/*!
|
|
@copydoc basic_json::crend()
|
|
*/
|
|
const_reverse_iterator rend() const
|
|
{
|
|
return crend();
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@requirement This function satisfies the ReversibleContainer requirements:
|
|
- The complexity is constant.
|
|
- Has the semantics of `const_cast<const basic_json&>(*this).rbegin()`.
|
|
|
|
@liveexample{The following code shows an example for @ref crbegin.,crbegin}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
const_reverse_iterator crbegin() const
|
|
{
|
|
return const_reverse_iterator(cend());
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@image html range-rbegin-rend.svg "Illustration from cppreference.com"
|
|
|
|
@complexity Constant.
|
|
|
|
@requirement This function satisfies the ReversibleContainer requirements:
|
|
- The complexity is constant.
|
|
- Has the semantics of `const_cast<const basic_json&>(*this).rend()`.
|
|
|
|
@liveexample{The following code shows an example for @ref crend.,crend}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
const_reverse_iterator crend() const
|
|
{
|
|
return const_reverse_iterator(cbegin());
|
|
}
|
|
|
|
private:
|
|
// forward declaration
|
|
template<typename IteratorType> class iteration_proxy;
|
|
|
|
public:
|
|
/*!
|
|
@brief wrapper to access iterator member functions in range-based for
|
|
|
|
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.
|
|
|
|
@note The name of this function is not yet final and may change in the
|
|
future.
|
|
*/
|
|
static iteration_proxy<iterator> iterator_wrapper(reference cont)
|
|
{
|
|
return iteration_proxy<iterator>(cont);
|
|
}
|
|
|
|
/*!
|
|
@copydoc iterator_wrapper(reference)
|
|
*/
|
|
static iteration_proxy<const_iterator> iterator_wrapper(const_reference cont)
|
|
{
|
|
return iteration_proxy<const_iterator>(cont);
|
|
}
|
|
|
|
/// @}
|
|
|
|
|
|
//////////////
|
|
// capacity //
|
|
//////////////
|
|
|
|
/// @name capacity
|
|
/// @{
|
|
|
|
/*!
|
|
@brief checks whether the container is empty
|
|
|
|
Checks if a JSON value has no elements.
|
|
|
|
@return The return value depends on the different types and is
|
|
defined as follows:
|
|
Value type | return value
|
|
----------- | -------------
|
|
null | @c true
|
|
boolean | @c false
|
|
string | @c false
|
|
number | @c false
|
|
object | result of function object_t::empty()
|
|
array | result of function array_t::empty()
|
|
|
|
@complexity Constant, as long as @ref array_t and @ref object_t satisfy the
|
|
Container concept; that is, their empty() functions have constant
|
|
complexity.
|
|
|
|
@requirement This function satisfies the Container requirements:
|
|
- The complexity is constant.
|
|
- Has the semantics of `begin() == end()`.
|
|
|
|
@liveexample{The following code uses @ref empty to check if a @ref json
|
|
object contains any elements.,empty}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
bool empty() const noexcept
|
|
{
|
|
switch (m_type)
|
|
{
|
|
case value_t::null:
|
|
{
|
|
// null values are empty
|
|
return true;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
return m_value.array->empty();
|
|
}
|
|
|
|
case value_t::object:
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
return m_value.object->empty();
|
|
}
|
|
|
|
default:
|
|
{
|
|
// all other types are nonempty
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@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 | @c 0
|
|
boolean | @c 1
|
|
string | @c 1
|
|
number | @c 1
|
|
object | result of function object_t::size()
|
|
array | result of function array_t::size()
|
|
|
|
@complexity Constant, as long as @ref array_t and @ref object_t satisfy the
|
|
Container concept; that is, their size() functions have constant complexity.
|
|
|
|
@requirement This function satisfies the Container requirements:
|
|
- The complexity is constant.
|
|
- Has the semantics of `std::distance(begin(), end())`.
|
|
|
|
@liveexample{The following code calls @ref size on the different value
|
|
types.,size}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
size_type size() const noexcept
|
|
{
|
|
switch (m_type)
|
|
{
|
|
case value_t::null:
|
|
{
|
|
// null values are empty
|
|
return 0;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
return m_value.array->size();
|
|
}
|
|
|
|
case value_t::object:
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
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 | @c 0 (same as size())
|
|
boolean | @c 1 (same as size())
|
|
string | @c 1 (same as size())
|
|
number | @c 1 (same as size())
|
|
object | result of function object_t::max_size()
|
|
array | result of function array_t::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.
|
|
|
|
@requirement This function satisfies the Container requirements:
|
|
- The complexity is constant.
|
|
- Has the semantics of returning `b.size()` where `b` is the largest
|
|
possible JSON value.
|
|
|
|
@liveexample{The following code calls @ref max_size on the different value
|
|
types. Note the output is implementation specific.,max_size}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
size_type max_size() const noexcept
|
|
{
|
|
switch (m_type)
|
|
{
|
|
case value_t::array:
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
return m_value.array->max_size();
|
|
}
|
|
|
|
case value_t::object:
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
return m_value.object->max_size();
|
|
}
|
|
|
|
default:
|
|
{
|
|
// all other types have max_size() == size()
|
|
return size();
|
|
}
|
|
}
|
|
}
|
|
|
|
/// @}
|
|
|
|
|
|
///////////////
|
|
// modifiers //
|
|
///////////////
|
|
|
|
/// @name modifiers
|
|
/// @{
|
|
|
|
/*!
|
|
@brief clears the contents
|
|
|
|
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:
|
|
|
|
Value type | initial value
|
|
----------- | -------------
|
|
null | `null`
|
|
boolean | `false`
|
|
string | `""`
|
|
number | `0`
|
|
object | `{}`
|
|
array | `[]`
|
|
|
|
@note Floating-point numbers are set to `0.0` which will be serialized to
|
|
`0`. The vale type remains @ref number_float_t.
|
|
|
|
@complexity Linear in the size of the JSON value.
|
|
|
|
@liveexample{The example below shows the effect of @ref clear to different
|
|
JSON types.,clear}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
void clear() noexcept
|
|
{
|
|
switch (m_type)
|
|
{
|
|
case value_t::number_integer:
|
|
{
|
|
m_value.number_integer = 0;
|
|
break;
|
|
}
|
|
|
|
case value_t::number_float:
|
|
{
|
|
m_value.number_float = 0.0;
|
|
break;
|
|
}
|
|
|
|
case value_t::boolean:
|
|
{
|
|
m_value.boolean = false;
|
|
break;
|
|
}
|
|
|
|
case value_t::string:
|
|
{
|
|
assert(m_value.string != nullptr);
|
|
m_value.string->clear();
|
|
break;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
m_value.array->clear();
|
|
break;
|
|
}
|
|
|
|
case value_t::object:
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
m_value.object->clear();
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief add an object to an array
|
|
|
|
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.
|
|
|
|
@param val the value to add to the JSON array
|
|
|
|
@throw std::domain_error when called on a type other than JSON array or
|
|
null; example: `"cannot use push_back() with number"`
|
|
|
|
@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
|
|
*/
|
|
void push_back(basic_json&& val)
|
|
{
|
|
// push_back only works for null objects or arrays
|
|
if (not(is_null() or is_array()))
|
|
{
|
|
throw std::domain_error("cannot use push_back() with " + type_name());
|
|
}
|
|
|
|
// transform null object into an array
|
|
if (is_null())
|
|
{
|
|
m_type = value_t::array;
|
|
m_value = value_t::array;
|
|
}
|
|
|
|
// add element to array (move semantics)
|
|
assert(m_value.array != nullptr);
|
|
m_value.array->push_back(std::move(val));
|
|
// invalidate object
|
|
val.m_type = value_t::null;
|
|
}
|
|
|
|
/*!
|
|
@brief add an object to an array
|
|
@copydoc push_back(basic_json&&)
|
|
*/
|
|
reference operator+=(basic_json&& val)
|
|
{
|
|
push_back(std::move(val));
|
|
return *this;
|
|
}
|
|
|
|
/*!
|
|
@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()))
|
|
{
|
|
throw std::domain_error("cannot use push_back() with " + type_name());
|
|
}
|
|
|
|
// transform null object into an array
|
|
if (is_null())
|
|
{
|
|
m_type = value_t::array;
|
|
m_value = value_t::array;
|
|
}
|
|
|
|
// add element to array
|
|
assert(m_value.array != nullptr);
|
|
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;
|
|
}
|
|
|
|
/*!
|
|
@brief add an object to an object
|
|
|
|
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.
|
|
|
|
@param[in] val the value to add to the JSON object
|
|
|
|
@throw std::domain_error when called on a type other than JSON object or
|
|
null; example: `"cannot use push_back() with number"`
|
|
|
|
@complexity Logarithmic in the size of the container, O(log(`size()`)).
|
|
|
|
@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}
|
|
|
|
@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()))
|
|
{
|
|
throw std::domain_error("cannot use push_back() with " + type_name());
|
|
}
|
|
|
|
// transform null object into an object
|
|
if (is_null())
|
|
{
|
|
m_type = value_t::object;
|
|
m_value = value_t::object;
|
|
}
|
|
|
|
// add element to array
|
|
assert(m_value.object != nullptr);
|
|
m_value.object->insert(val);
|
|
}
|
|
|
|
/*!
|
|
@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 operator[](val.first);
|
|
}
|
|
|
|
/*!
|
|
@brief inserts element
|
|
|
|
Inserts element @a val before iterator @a pos.
|
|
|
|
@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.
|
|
|
|
@throw std::domain_error if called on JSON values other than arrays;
|
|
example: `"cannot use insert() with string"`
|
|
@throw std::domain_error if @a pos is not an iterator of *this; example:
|
|
`"iterator does not fit current value"`
|
|
|
|
@complexity Constant plus linear in the distance between pos and end of the
|
|
container.
|
|
|
|
@liveexample{The example shows how insert is used.,insert}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
iterator insert(const_iterator pos, const basic_json& val)
|
|
{
|
|
// insert only works for arrays
|
|
if (is_array())
|
|
{
|
|
// check if iterator pos fits to this JSON value
|
|
if (pos.m_object != this)
|
|
{
|
|
throw std::domain_error("iterator does not fit current value");
|
|
}
|
|
|
|
// insert to array and return iterator
|
|
iterator result(this);
|
|
assert(m_value.array != nullptr);
|
|
result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, val);
|
|
return result;
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use insert() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief inserts element
|
|
@copydoc insert(const_iterator, const basic_json&)
|
|
*/
|
|
iterator insert(const_iterator pos, basic_json&& val)
|
|
{
|
|
return insert(pos, val);
|
|
}
|
|
|
|
/*!
|
|
@brief inserts elements
|
|
|
|
Inserts @a cnt copies of @a val before iterator @a pos.
|
|
|
|
@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`
|
|
|
|
@throw std::domain_error if called on JSON values other than arrays;
|
|
example: `"cannot use insert() with string"`
|
|
@throw std::domain_error if @a pos is not an iterator of *this; example:
|
|
`"iterator does not fit current value"`
|
|
|
|
@complexity Linear in @a cnt plus linear in the distance between @a pos
|
|
and end of the container.
|
|
|
|
@liveexample{The example shows how insert is used.,insert__count}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
iterator insert(const_iterator pos, size_type cnt, const basic_json& val)
|
|
{
|
|
// insert only works for arrays
|
|
if (is_array())
|
|
{
|
|
// check if iterator pos fits to this JSON value
|
|
if (pos.m_object != this)
|
|
{
|
|
throw std::domain_error("iterator does not fit current value");
|
|
}
|
|
|
|
// insert to array and return iterator
|
|
iterator result(this);
|
|
assert(m_value.array != nullptr);
|
|
result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val);
|
|
return result;
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use insert() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief inserts elements
|
|
|
|
Inserts elements from range `[first, last)` before iterator @a pos.
|
|
|
|
@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 std::domain_error if called on JSON values other than arrays;
|
|
example: `"cannot use insert() with string"`
|
|
@throw std::domain_error if @a pos is not an iterator of *this; example:
|
|
`"iterator does not fit current value"`
|
|
@throw std::domain_error if @a first and @a last do not belong to the same
|
|
JSON value; example: `"iterators do not fit"`
|
|
@throw std::domain_error 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.
|
|
|
|
@liveexample{The example shows how insert is used.,insert__range}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
iterator insert(const_iterator pos, const_iterator first, const_iterator last)
|
|
{
|
|
// insert only works for arrays
|
|
if (not is_array())
|
|
{
|
|
throw std::domain_error("cannot use insert() with " + type_name());
|
|
}
|
|
|
|
// check if iterator pos fits to this JSON value
|
|
if (pos.m_object != this)
|
|
{
|
|
throw std::domain_error("iterator does not fit current value");
|
|
}
|
|
|
|
if (first.m_object != last.m_object)
|
|
{
|
|
throw std::domain_error("iterators do not fit");
|
|
}
|
|
|
|
if (first.m_object == this or last.m_object == this)
|
|
{
|
|
throw std::domain_error("passed iterators may not belong to container");
|
|
}
|
|
|
|
// insert to array and return iterator
|
|
iterator result(this);
|
|
assert(m_value.array != nullptr);
|
|
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;
|
|
}
|
|
|
|
/*!
|
|
@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 std::domain_error if called on JSON values other than arrays;
|
|
example: `"cannot use insert() with string"`
|
|
@throw std::domain_error if @a pos is not an iterator of *this; example:
|
|
`"iterator does not fit current value"`
|
|
|
|
@return iterator pointing to the first element inserted, or @a pos if
|
|
`ilist` is empty
|
|
|
|
@complexity Linear in `ilist.size()` plus linear in the distance between @a
|
|
pos and end of the container.
|
|
|
|
@liveexample{The example shows how insert is used.,insert__ilist}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
iterator insert(const_iterator pos, std::initializer_list<basic_json> ilist)
|
|
{
|
|
// insert only works for arrays
|
|
if (not is_array())
|
|
{
|
|
throw std::domain_error("cannot use insert() with " + type_name());
|
|
}
|
|
|
|
// check if iterator pos fits to this JSON value
|
|
if (pos.m_object != this)
|
|
{
|
|
throw std::domain_error("iterator does not fit current value");
|
|
}
|
|
|
|
// insert to array and return iterator
|
|
iterator result(this);
|
|
assert(m_value.array != nullptr);
|
|
result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist);
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief exchanges the values
|
|
|
|
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.
|
|
|
|
@param[in,out] other JSON value to exchange the contents with
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows how JSON arrays can be
|
|
swapped.,swap__reference}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
void swap(reference other) noexcept (
|
|
std::is_nothrow_move_constructible<value_t>::value and
|
|
std::is_nothrow_move_assignable<value_t>::value and
|
|
std::is_nothrow_move_constructible<json_value>::value and
|
|
std::is_nothrow_move_assignable<json_value>::value
|
|
)
|
|
{
|
|
std::swap(m_type, other.m_type);
|
|
std::swap(m_value, other.m_value);
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@param[in,out] other array to exchange the contents with
|
|
|
|
@throw std::domain_error when JSON value is not an array; example: `"cannot
|
|
use swap() with string"`
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows how JSON values can be
|
|
swapped.,swap__array_t}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
void swap(array_t& other)
|
|
{
|
|
// swap only works for arrays
|
|
if (is_array())
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
std::swap(*(m_value.array), other);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use swap() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@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.
|
|
|
|
@param[in,out] other object to exchange the contents with
|
|
|
|
@throw std::domain_error when JSON value is not an object; example:
|
|
`"cannot use swap() with string"`
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows how JSON values can be
|
|
swapped.,swap__object_t}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
void swap(object_t& other)
|
|
{
|
|
// swap only works for objects
|
|
if (is_object())
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
std::swap(*(m_value.object), other);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use swap() with " + 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 std::domain_error when JSON value is not a string; example: `"cannot
|
|
use swap() with boolean"`
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example below shows how JSON values can be
|
|
swapped.,swap__string_t}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
void swap(string_t& other)
|
|
{
|
|
// swap only works for strings
|
|
if (is_string())
|
|
{
|
|
assert(m_value.string != nullptr);
|
|
std::swap(*(m_value.string), other);
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use swap() with " + type_name());
|
|
}
|
|
}
|
|
|
|
/// @}
|
|
|
|
|
|
//////////////////////////////////////////
|
|
// lexicographical comparison operators //
|
|
//////////////////////////////////////////
|
|
|
|
/// @name lexicographical comparison operators
|
|
/// @{
|
|
|
|
private:
|
|
/*!
|
|
@brief comparison operator for JSON types
|
|
|
|
Returns an ordering that is similar to Python:
|
|
- order: null < boolean < number < object < array < string
|
|
- furthermore, each type is not smaller than itself
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
friend bool operator<(const value_t lhs, const value_t rhs)
|
|
{
|
|
static constexpr std::array<uint8_t, 7> order = {{
|
|
0, // null
|
|
3, // object
|
|
4, // array
|
|
5, // string
|
|
1, // boolean
|
|
2, // integer
|
|
2 // float
|
|
}
|
|
};
|
|
|
|
// discarded values are not comparable
|
|
if (lhs == value_t::discarded or rhs == value_t::discarded)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
return order[static_cast<std::size_t>(lhs)] < order[static_cast<std::size_t>(rhs)];
|
|
}
|
|
|
|
public:
|
|
/*!
|
|
@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.
|
|
- 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.
|
|
- Two JSON null values are equal.
|
|
|
|
@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.
|
|
|
|
@liveexample{The example demonstrates comparing several JSON
|
|
types.,operator__equal}
|
|
|
|
@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 value_t::array:
|
|
{
|
|
assert(lhs.m_value.array != nullptr);
|
|
assert(rhs.m_value.array != nullptr);
|
|
return *lhs.m_value.array == *rhs.m_value.array;
|
|
}
|
|
case value_t::object:
|
|
{
|
|
assert(lhs.m_value.object != nullptr);
|
|
assert(rhs.m_value.object != nullptr);
|
|
return *lhs.m_value.object == *rhs.m_value.object;
|
|
}
|
|
case value_t::null:
|
|
{
|
|
return true;
|
|
}
|
|
case value_t::string:
|
|
{
|
|
assert(lhs.m_value.string != nullptr);
|
|
assert(rhs.m_value.string != nullptr);
|
|
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_float:
|
|
{
|
|
return approx(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 approx(static_cast<number_float_t>(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 approx(lhs.m_value.number_float,
|
|
static_cast<number_float_t>(rhs.m_value.number_integer));
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*!
|
|
@brief comparison: equal
|
|
|
|
The functions compares the given JSON value against a null pointer. As the
|
|
null pointer can be used to initialize a JSON value to null, a comparison
|
|
of JSON value @a v with a null pointer should be equivalent to call
|
|
`v.is_null()`.
|
|
|
|
@param[in] v JSON value to consider
|
|
@return whether @a v is null
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example compares several JSON types to the null pointer.
|
|
,operator__equal__nullptr_t}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
friend bool operator==(const_reference v, std::nullptr_t) noexcept
|
|
{
|
|
return v.is_null();
|
|
}
|
|
|
|
/*!
|
|
@brief comparison: equal
|
|
@copydoc operator==(const_reference, std::nullptr_t)
|
|
*/
|
|
friend bool operator==(std::nullptr_t, const_reference v) noexcept
|
|
{
|
|
return v.is_null();
|
|
}
|
|
|
|
/*!
|
|
@brief comparison: not equal
|
|
|
|
Compares two JSON values for inequality by calculating `not (lhs == rhs)`.
|
|
|
|
@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
|
|
|
|
@complexity Linear.
|
|
|
|
@liveexample{The example demonstrates comparing several JSON
|
|
types.,operator__notequal}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
friend bool operator!=(const_reference lhs, const_reference rhs) noexcept
|
|
{
|
|
return not (lhs == rhs);
|
|
}
|
|
|
|
/*!
|
|
@brief comparison: not equal
|
|
|
|
The functions compares the given JSON value against a null pointer. As the
|
|
null pointer can be used to initialize a JSON value to null, a comparison
|
|
of JSON value @a v with a null pointer should be equivalent to call
|
|
`not v.is_null()`.
|
|
|
|
@param[in] v JSON value to consider
|
|
@return whether @a v is not null
|
|
|
|
@complexity Constant.
|
|
|
|
@liveexample{The example compares several JSON types to the null pointer.
|
|
,operator__notequal__nullptr_t}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
friend bool operator!=(const_reference v, std::nullptr_t) noexcept
|
|
{
|
|
return not v.is_null();
|
|
}
|
|
|
|
/*!
|
|
@brief comparison: not equal
|
|
@copydoc operator!=(const_reference, std::nullptr_t)
|
|
*/
|
|
friend bool operator!=(std::nullptr_t, const_reference v) noexcept
|
|
{
|
|
return not v.is_null();
|
|
}
|
|
|
|
/*!
|
|
@brief comparison: less than
|
|
|
|
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).
|
|
|
|
@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
|
|
|
|
@complexity Linear.
|
|
|
|
@liveexample{The example demonstrates comparing several JSON
|
|
types.,operator__less}
|
|
|
|
@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 value_t::array:
|
|
{
|
|
assert(lhs.m_value.array != nullptr);
|
|
assert(rhs.m_value.array != nullptr);
|
|
return *lhs.m_value.array < *rhs.m_value.array;
|
|
}
|
|
case value_t::object:
|
|
{
|
|
assert(lhs.m_value.object != nullptr);
|
|
assert(rhs.m_value.object != nullptr);
|
|
return *lhs.m_value.object < *rhs.m_value.object;
|
|
}
|
|
case value_t::null:
|
|
{
|
|
return false;
|
|
}
|
|
case value_t::string:
|
|
{
|
|
assert(lhs.m_value.string != nullptr);
|
|
assert(rhs.m_value.string != nullptr);
|
|
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_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<number_float_t>(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<number_float_t>(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);
|
|
}
|
|
|
|
/*!
|
|
@brief comparison: less than or equal
|
|
|
|
Compares whether one JSON value @a lhs is less than or equal to another
|
|
JSON value by calculating `not (rhs < lhs)`.
|
|
|
|
@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
|
|
|
|
@complexity Linear.
|
|
|
|
@liveexample{The example demonstrates comparing several JSON
|
|
types.,operator__greater}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
friend bool operator<=(const_reference lhs, const_reference rhs) noexcept
|
|
{
|
|
return not (rhs < lhs);
|
|
}
|
|
|
|
/*!
|
|
@brief comparison: greater than
|
|
|
|
Compares whether one JSON value @a lhs is greater than another
|
|
JSON value by calculating `not (lhs <= rhs)`.
|
|
|
|
@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
|
|
|
|
@complexity Linear.
|
|
|
|
@liveexample{The example demonstrates comparing several JSON
|
|
types.,operator__lessequal}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
friend bool operator>(const_reference lhs, const_reference rhs) noexcept
|
|
{
|
|
return not (lhs <= rhs);
|
|
}
|
|
|
|
/*!
|
|
@brief comparison: greater than or equal
|
|
|
|
Compares whether one JSON value @a lhs is greater than or equal to another
|
|
JSON value by calculating `not (lhs < rhs)`.
|
|
|
|
@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
|
|
|
|
@complexity Linear.
|
|
|
|
@liveexample{The example demonstrates comparing several JSON
|
|
types.,operator__greaterequal}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
friend bool operator>=(const_reference lhs, const_reference rhs) noexcept
|
|
{
|
|
return not (lhs < rhs);
|
|
}
|
|
|
|
/// @}
|
|
|
|
|
|
///////////////////
|
|
// serialization //
|
|
///////////////////
|
|
|
|
/// @name serialization
|
|
/// @{
|
|
|
|
/*!
|
|
@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)`.
|
|
|
|
@param[in,out] o stream to serialize to
|
|
@param[in] j JSON value to serialize
|
|
|
|
@return the stream @a o
|
|
|
|
@complexity Linear.
|
|
|
|
@liveexample{The example below shows the serialization with different
|
|
parameters to `width` to adjust the indentation level.,operator_serialize}
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
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);
|
|
|
|
// reset width to 0 for subsequent calls to this stream
|
|
o.width(0);
|
|
|
|
// do the actual serialization
|
|
j.dump(o, pretty_print, static_cast<unsigned int>(indentation));
|
|
return o;
|
|
}
|
|
|
|
/*!
|
|
@brief serialize to stream
|
|
@copydoc operator<<(std::ostream&, const basic_json&)
|
|
*/
|
|
friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
|
|
{
|
|
return o << j;
|
|
}
|
|
|
|
/// @}
|
|
|
|
|
|
/////////////////////
|
|
// deserialization //
|
|
/////////////////////
|
|
|
|
/// @name deserialization
|
|
/// @{
|
|
|
|
/*!
|
|
@brief deserialize from string
|
|
|
|
@param[in] s string 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)
|
|
|
|
@return result of the deserialization
|
|
|
|
@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.
|
|
|
|
@note A UTF-8 byte order mark is silently ignored.
|
|
|
|
@liveexample{The example below demonstrates the parse function with and
|
|
without callback function.,parse__string__parser_callback_t}
|
|
|
|
@sa @ref parse(std::istream&, parser_callback_t) for a version that reads
|
|
from an input stream
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
static basic_json parse(const string_t& s, parser_callback_t cb = nullptr)
|
|
{
|
|
return parser(s, cb).parse();
|
|
}
|
|
|
|
/*!
|
|
@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)
|
|
|
|
@return result of the deserialization
|
|
|
|
@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.
|
|
|
|
@note A UTF-8 byte order mark is silently ignored.
|
|
|
|
@liveexample{The example below demonstrates the parse function with and
|
|
without callback function.,parse__istream__parser_callback_t}
|
|
|
|
@sa @ref parse(const string_t&, parser_callback_t) for a version that reads
|
|
from a string
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
static basic_json parse(std::istream& i, parser_callback_t cb = nullptr)
|
|
{
|
|
return parser(i, cb).parse();
|
|
}
|
|
|
|
/*!
|
|
@copydoc parse(std::istream&, parser_callback_t)
|
|
*/
|
|
static basic_json parse(std::istream&& i, parser_callback_t cb = nullptr)
|
|
{
|
|
return parser(i, cb).parse();
|
|
}
|
|
|
|
/*!
|
|
@brief deserialize from stream
|
|
|
|
Deserializes an input stream to a JSON value.
|
|
|
|
@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
|
|
|
|
@throw std::invalid_argument in case of parse errors
|
|
|
|
@complexity Linear in the length of the input. The parser is a predictive
|
|
LL(1) parser.
|
|
|
|
@note A UTF-8 byte order mark is silently ignored.
|
|
|
|
@liveexample{The example below shows how a JSON value is constructed by
|
|
reading a serialization from a stream.,operator_deserialize}
|
|
|
|
@sa parse(std::istream&, parser_callback_t) for a variant with a parser
|
|
callback function to filter values while parsing
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
friend std::istream& operator<<(basic_json& j, std::istream& i)
|
|
{
|
|
j = parser(i).parse();
|
|
return i;
|
|
}
|
|
|
|
/*!
|
|
@brief deserialize from stream
|
|
@copydoc operator<<(basic_json&, std::istream&)
|
|
*/
|
|
friend std::istream& operator>>(std::istream& i, basic_json& j)
|
|
{
|
|
j = parser(i).parse();
|
|
return i;
|
|
}
|
|
|
|
/// @}
|
|
|
|
|
|
private:
|
|
///////////////////////////
|
|
// convenience functions //
|
|
///////////////////////////
|
|
|
|
/// return the type as string
|
|
string_t type_name() const
|
|
{
|
|
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";
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@brief calculates the extra space to escape a JSON string
|
|
|
|
@param[in] s the string to escape
|
|
@return the number of characters required to escape string @a s
|
|
|
|
@complexity Linear in the length of string @a s.
|
|
*/
|
|
static std::size_t extra_space(const string_t& s) noexcept
|
|
{
|
|
std::size_t result = 0;
|
|
|
|
for (const auto& c : s)
|
|
{
|
|
switch (c)
|
|
{
|
|
case '"':
|
|
case '\\':
|
|
case '\b':
|
|
case '\f':
|
|
case '\n':
|
|
case '\r':
|
|
case '\t':
|
|
{
|
|
// from c (1 byte) to \x (2 bytes)
|
|
result += 1;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
if (c >= 0x00 and c <= 0x1f)
|
|
{
|
|
// from c (1 byte) to \uxxxx (6 bytes)
|
|
result += 5;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief escape a 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.
|
|
|
|
@param[in] s the string to escape
|
|
@return the escaped string
|
|
|
|
@complexity Linear in the length of string @a s.
|
|
*/
|
|
static string_t escape_string(const string_t& s) noexcept
|
|
{
|
|
const auto space = extra_space(s);
|
|
if (space == 0)
|
|
{
|
|
return s;
|
|
}
|
|
|
|
// create a result string of necessary size
|
|
string_t result(s.size() + space, '\\');
|
|
std::size_t pos = 0;
|
|
|
|
for (const auto& c : s)
|
|
{
|
|
switch (c)
|
|
{
|
|
// quotation mark (0x22)
|
|
case '"':
|
|
{
|
|
result[pos + 1] = '"';
|
|
pos += 2;
|
|
break;
|
|
}
|
|
|
|
// 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;
|
|
}
|
|
|
|
// newline (0x0a)
|
|
case '\n':
|
|
{
|
|
result[pos + 1] = 'n';
|
|
pos += 2;
|
|
break;
|
|
}
|
|
|
|
// carriage return (0x0d)
|
|
case '\r':
|
|
{
|
|
result[pos + 1] = 'r';
|
|
pos += 2;
|
|
break;
|
|
}
|
|
|
|
// horizontal tab (0x09)
|
|
case '\t':
|
|
{
|
|
result[pos + 1] = 't';
|
|
pos += 2;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
if (c >= 0x00 and c <= 0x1f)
|
|
{
|
|
// convert a number 0..15 to its hex representation (0..f)
|
|
auto hexify = [](const char v) -> char
|
|
{
|
|
return (v < 10) ? ('0' + v) : ('a' + v - 10);
|
|
};
|
|
|
|
// print character c as \uxxxx
|
|
for (const char m :
|
|
{ 'u', '0', '0', hexify(c >> 4), hexify(c & 0x0f)
|
|
})
|
|
{
|
|
result[++pos] = m;
|
|
}
|
|
|
|
++pos;
|
|
}
|
|
else
|
|
{
|
|
// all other characters are added as-is
|
|
result[pos++] = c;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief internal implementation of the serialization function
|
|
|
|
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. Note that
|
|
|
|
- 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
|
|
|
|
@param[out] o stream to write to
|
|
@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(std::ostream& o,
|
|
const bool pretty_print,
|
|
const unsigned int indent_step,
|
|
const unsigned int current_indent = 0) const
|
|
{
|
|
// variable to hold indentation for recursive calls
|
|
unsigned int new_indent = current_indent;
|
|
|
|
switch (m_type)
|
|
{
|
|
case value_t::object:
|
|
{
|
|
assert(m_value.object != nullptr);
|
|
|
|
if (m_value.object->empty())
|
|
{
|
|
o << "{}";
|
|
return;
|
|
}
|
|
|
|
o << "{";
|
|
|
|
// increase indentation
|
|
if (pretty_print)
|
|
{
|
|
new_indent += indent_step;
|
|
o << "\n";
|
|
}
|
|
|
|
for (auto i = m_value.object->cbegin(); i != m_value.object->cend(); ++i)
|
|
{
|
|
if (i != m_value.object->cbegin())
|
|
{
|
|
o << (pretty_print ? ",\n" : ",");
|
|
}
|
|
o << string_t(new_indent, ' ') << "\""
|
|
<< escape_string(i->first) << "\":"
|
|
<< (pretty_print ? " " : "");
|
|
i->second.dump(o, pretty_print, indent_step, new_indent);
|
|
}
|
|
|
|
// decrease indentation
|
|
if (pretty_print)
|
|
{
|
|
new_indent -= indent_step;
|
|
o << "\n";
|
|
}
|
|
|
|
o << string_t(new_indent, ' ') + "}";
|
|
return;
|
|
}
|
|
|
|
case value_t::array:
|
|
{
|
|
assert(m_value.array != nullptr);
|
|
|
|
if (m_value.array->empty())
|
|
{
|
|
o << "[]";
|
|
return;
|
|
}
|
|
|
|
o << "[";
|
|
|
|
// increase indentation
|
|
if (pretty_print)
|
|
{
|
|
new_indent += indent_step;
|
|
o << "\n";
|
|
}
|
|
|
|
for (auto i = m_value.array->cbegin(); i != m_value.array->cend(); ++i)
|
|
{
|
|
if (i != m_value.array->cbegin())
|
|
{
|
|
o << (pretty_print ? ",\n" : ",");
|
|
}
|
|
o << string_t(new_indent, ' ');
|
|
i->dump(o, pretty_print, indent_step, new_indent);
|
|
}
|
|
|
|
// decrease indentation
|
|
if (pretty_print)
|
|
{
|
|
new_indent -= indent_step;
|
|
o << "\n";
|
|
}
|
|
|
|
o << string_t(new_indent, ' ') << "]";
|
|
return;
|
|
}
|
|
|
|
case value_t::string:
|
|
{
|
|
assert(m_value.string != nullptr);
|
|
o << string_t("\"") << escape_string(*m_value.string) << "\"";
|
|
return;
|
|
}
|
|
|
|
case value_t::boolean:
|
|
{
|
|
o << (m_value.boolean ? "true" : "false");
|
|
return;
|
|
}
|
|
|
|
case value_t::number_integer:
|
|
{
|
|
o << m_value.number_integer;
|
|
return;
|
|
}
|
|
|
|
case value_t::number_float:
|
|
{
|
|
// 15 digits of precision allows round-trip IEEE 754
|
|
// string->double->string; to be safe, we read this value from
|
|
// std::numeric_limits<number_float_t>::digits10
|
|
o << std::setprecision(std::numeric_limits<number_float_t>::digits10) << m_value.number_float;
|
|
return;
|
|
}
|
|
|
|
case value_t::discarded:
|
|
{
|
|
o << "<discarded>";
|
|
return;
|
|
}
|
|
|
|
case value_t::null:
|
|
{
|
|
o << "null";
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
private:
|
|
//////////////////////
|
|
// member variables //
|
|
//////////////////////
|
|
|
|
/// the type of the current element
|
|
value_t m_type = value_t::null;
|
|
|
|
/// the value of the current element
|
|
json_value m_value = {};
|
|
|
|
|
|
private:
|
|
///////////////
|
|
// iterators //
|
|
///////////////
|
|
|
|
/*!
|
|
@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
|
|
{
|
|
public:
|
|
/// set iterator to a defined beginning
|
|
void set_begin()
|
|
{
|
|
m_it = begin_value;
|
|
}
|
|
|
|
/// set iterator to a defined past the end
|
|
void set_end()
|
|
{
|
|
m_it = end_value;
|
|
}
|
|
|
|
/// return whether the iterator can be dereferenced
|
|
bool is_begin() const
|
|
{
|
|
return (m_it == begin_value);
|
|
}
|
|
|
|
/// return whether the iterator is at end
|
|
bool is_end() const
|
|
{
|
|
return (m_it == end_value);
|
|
}
|
|
|
|
/// return reference to the value to change and compare
|
|
operator difference_type& ()
|
|
{
|
|
return m_it;
|
|
}
|
|
|
|
/// return value to compare
|
|
operator difference_type () const
|
|
{
|
|
return m_it;
|
|
}
|
|
|
|
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<std::ptrdiff_t>::denorm_min();
|
|
};
|
|
|
|
/*!
|
|
@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.
|
|
*/
|
|
struct internal_iterator
|
|
{
|
|
/// 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()
|
|
: object_iterator(), array_iterator(), primitive_iterator()
|
|
{}
|
|
};
|
|
|
|
/// proxy class for the iterator_wrapper functions
|
|
template<typename IteratorType>
|
|
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;
|
|
|
|
public:
|
|
iteration_proxy_internal(IteratorType it)
|
|
: 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
|
|
{
|
|
return anchor != o.anchor;
|
|
}
|
|
|
|
/// return key of the iterator
|
|
typename basic_json::string_t key() const
|
|
{
|
|
assert(anchor.m_object != nullptr);
|
|
|
|
switch (anchor.m_object->type())
|
|
{
|
|
// use integer array index as key
|
|
case value_t::array:
|
|
{
|
|
return std::to_string(array_index);
|
|
}
|
|
|
|
// use key from the object
|
|
case value_t::object:
|
|
{
|
|
return anchor.key();
|
|
}
|
|
|
|
// use an empty key for all primitive types
|
|
default:
|
|
{
|
|
return "";
|
|
}
|
|
}
|
|
}
|
|
|
|
/// return value of the iterator
|
|
typename IteratorType::reference value() const
|
|
{
|
|
return anchor.value();
|
|
}
|
|
};
|
|
|
|
/// the container to iterate
|
|
typename IteratorType::reference container;
|
|
|
|
public:
|
|
/// construct iteration proxy from a container
|
|
iteration_proxy(typename IteratorType::reference cont)
|
|
: container(cont)
|
|
{}
|
|
|
|
/// return iterator begin (needed for range-based for)
|
|
iteration_proxy_internal begin()
|
|
{
|
|
return iteration_proxy_internal(container.begin());
|
|
}
|
|
|
|
/// return iterator end (needed for range-based for)
|
|
iteration_proxy_internal end()
|
|
{
|
|
return iteration_proxy_internal(container.end());
|
|
}
|
|
};
|
|
|
|
public:
|
|
/*!
|
|
@brief a const random access iterator for the @ref basic_json class
|
|
|
|
This class implements a const iterator for the @ref basic_json class. From
|
|
this class, the @ref iterator class is derived.
|
|
|
|
@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
|
|
*/
|
|
class const_iterator : public std::iterator<std::random_access_iterator_tag, const basic_json>
|
|
{
|
|
/// allow basic_json to access private members
|
|
friend class basic_json;
|
|
|
|
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 basic_json::const_pointer;
|
|
/// defines a reference to the type iterated over (value_type)
|
|
using reference = typename basic_json::const_reference;
|
|
/// the category of the iterator
|
|
using iterator_category = std::bidirectional_iterator_tag;
|
|
|
|
/// default constructor
|
|
const_iterator() = default;
|
|
|
|
/// constructor for a given JSON instance
|
|
const_iterator(pointer object) : 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;
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
m_it.array_iterator = typename array_t::iterator();
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
m_it.primitive_iterator = primitive_iterator_t();
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// copy constructor given a nonconst iterator
|
|
const_iterator(const iterator& other) : m_object(other.m_object)
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
m_it.object_iterator = other.m_it.object_iterator;
|
|
break;
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
m_it.array_iterator = other.m_it.array_iterator;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
m_it.primitive_iterator = other.m_it.primitive_iterator;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// copy constructor
|
|
const_iterator(const const_iterator& other) noexcept
|
|
: m_object(other.m_object), m_it(other.m_it)
|
|
{}
|
|
|
|
/// copy assignment
|
|
const_iterator& operator=(const_iterator other) noexcept(
|
|
std::is_nothrow_move_constructible<pointer>::value and
|
|
std::is_nothrow_move_assignable<pointer>::value and
|
|
std::is_nothrow_move_constructible<internal_iterator>::value and
|
|
std::is_nothrow_move_assignable<internal_iterator>::value
|
|
)
|
|
{
|
|
std::swap(m_object, other.m_object);
|
|
std::swap(m_it, other.m_it);
|
|
return *this;
|
|
}
|
|
|
|
private:
|
|
/// set the iterator to the first value
|
|
void set_begin()
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
assert(m_object->m_value.object != nullptr);
|
|
m_it.object_iterator = m_object->m_value.object->begin();
|
|
break;
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
assert(m_object->m_value.array != nullptr);
|
|
m_it.array_iterator = m_object->m_value.array->begin();
|
|
break;
|
|
}
|
|
|
|
case basic_json::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;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// set the iterator past the last value
|
|
void set_end()
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
assert(m_object->m_value.object != nullptr);
|
|
m_it.object_iterator = m_object->m_value.object->end();
|
|
break;
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
assert(m_object->m_value.array != nullptr);
|
|
m_it.array_iterator = m_object->m_value.array->end();
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
m_it.primitive_iterator.set_end();
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
public:
|
|
/// return a reference to the value pointed to by the iterator
|
|
reference operator*() const
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
assert(m_object->m_value.object);
|
|
assert(m_it.object_iterator != m_object->m_value.object->end());
|
|
return m_it.object_iterator->second;
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
assert(m_object->m_value.array);
|
|
assert(m_it.array_iterator != m_object->m_value.array->end());
|
|
return *m_it.array_iterator;
|
|
}
|
|
|
|
case basic_json::value_t::null:
|
|
{
|
|
throw std::out_of_range("cannot get value");
|
|
}
|
|
|
|
default:
|
|
{
|
|
if (m_it.primitive_iterator.is_begin())
|
|
{
|
|
return *m_object;
|
|
}
|
|
else
|
|
{
|
|
throw std::out_of_range("cannot get value");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// dereference the iterator
|
|
pointer operator->() const
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
assert(m_object->m_value.object);
|
|
assert(m_it.object_iterator != m_object->m_value.object->end());
|
|
return &(m_it.object_iterator->second);
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
assert(m_object->m_value.array);
|
|
assert(m_it.array_iterator != m_object->m_value.array->end());
|
|
return &*m_it.array_iterator;
|
|
}
|
|
|
|
default:
|
|
{
|
|
if (m_it.primitive_iterator.is_begin())
|
|
{
|
|
return m_object;
|
|
}
|
|
else
|
|
{
|
|
throw std::out_of_range("cannot get value");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// post-increment (it++)
|
|
const_iterator operator++(int)
|
|
{
|
|
auto result = *this;
|
|
++(*this);
|
|
return result;
|
|
}
|
|
|
|
/// pre-increment (++it)
|
|
const_iterator& operator++()
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
++m_it.object_iterator;
|
|
break;
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
++m_it.array_iterator;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
++m_it.primitive_iterator;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
/// post-decrement (it--)
|
|
const_iterator operator--(int)
|
|
{
|
|
auto result = *this;
|
|
--(*this);
|
|
return result;
|
|
}
|
|
|
|
/// pre-decrement (--it)
|
|
const_iterator& operator--()
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
--m_it.object_iterator;
|
|
break;
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
--m_it.array_iterator;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
--m_it.primitive_iterator;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
/// comparison: equal
|
|
bool operator==(const const_iterator& other) const
|
|
{
|
|
// if objects are not the same, the comparison is undefined
|
|
if (m_object != other.m_object)
|
|
{
|
|
throw std::domain_error("cannot compare iterators of different containers");
|
|
}
|
|
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
return (m_it.object_iterator == other.m_it.object_iterator);
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
return (m_it.array_iterator == other.m_it.array_iterator);
|
|
}
|
|
|
|
default:
|
|
{
|
|
return (m_it.primitive_iterator == other.m_it.primitive_iterator);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// comparison: not equal
|
|
bool operator!=(const const_iterator& other) const
|
|
{
|
|
return not operator==(other);
|
|
}
|
|
|
|
/// comparison: smaller
|
|
bool operator<(const const_iterator& other) const
|
|
{
|
|
// if objects are not the same, the comparison is undefined
|
|
if (m_object != other.m_object)
|
|
{
|
|
throw std::domain_error("cannot compare iterators of different containers");
|
|
}
|
|
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
throw std::domain_error("cannot compare order of object iterators");
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
return (m_it.array_iterator < other.m_it.array_iterator);
|
|
}
|
|
|
|
default:
|
|
{
|
|
return (m_it.primitive_iterator < other.m_it.primitive_iterator);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// comparison: less than or equal
|
|
bool operator<=(const const_iterator& other) const
|
|
{
|
|
return not other.operator < (*this);
|
|
}
|
|
|
|
/// comparison: greater than
|
|
bool operator>(const const_iterator& other) const
|
|
{
|
|
return not operator<=(other);
|
|
}
|
|
|
|
/// comparison: greater than or equal
|
|
bool operator>=(const const_iterator& other) const
|
|
{
|
|
return not operator<(other);
|
|
}
|
|
|
|
/// add to iterator
|
|
const_iterator& operator+=(difference_type i)
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
throw std::domain_error("cannot use offsets with object iterators");
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
m_it.array_iterator += i;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
m_it.primitive_iterator += i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
/// subtract from iterator
|
|
const_iterator& operator-=(difference_type i)
|
|
{
|
|
return operator+=(-i);
|
|
}
|
|
|
|
/// add to iterator
|
|
const_iterator operator+(difference_type i)
|
|
{
|
|
auto result = *this;
|
|
result += i;
|
|
return result;
|
|
}
|
|
|
|
/// subtract from iterator
|
|
const_iterator operator-(difference_type i)
|
|
{
|
|
auto result = *this;
|
|
result -= i;
|
|
return result;
|
|
}
|
|
|
|
/// return difference
|
|
difference_type operator-(const const_iterator& other) const
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
throw std::domain_error("cannot use offsets with object iterators");
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
return m_it.array_iterator - other.m_it.array_iterator;
|
|
}
|
|
|
|
default:
|
|
{
|
|
return m_it.primitive_iterator - other.m_it.primitive_iterator;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// access to successor
|
|
reference operator[](difference_type n) const
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
switch (m_object->m_type)
|
|
{
|
|
case basic_json::value_t::object:
|
|
{
|
|
throw std::domain_error("cannot use operator[] for object iterators");
|
|
}
|
|
|
|
case basic_json::value_t::array:
|
|
{
|
|
return *(m_it.array_iterator + n);
|
|
}
|
|
|
|
case basic_json::value_t::null:
|
|
{
|
|
throw std::out_of_range("cannot get value");
|
|
}
|
|
|
|
default:
|
|
{
|
|
if (m_it.primitive_iterator == -n)
|
|
{
|
|
return *m_object;
|
|
}
|
|
else
|
|
{
|
|
throw std::out_of_range("cannot get value");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// return the key of an object iterator
|
|
typename object_t::key_type key() const
|
|
{
|
|
assert(m_object != nullptr);
|
|
|
|
if (m_object->is_object())
|
|
{
|
|
return m_it.object_iterator->first;
|
|
}
|
|
else
|
|
{
|
|
throw std::domain_error("cannot use key() for non-object iterators");
|
|
}
|
|
}
|
|
|
|
/// return the value of an iterator
|
|
reference value() const
|
|
{
|
|
return operator*();
|
|
}
|
|
|
|
private:
|
|
/// associated JSON instance
|
|
pointer m_object = nullptr;
|
|
/// the actual iterator of the associated instance
|
|
internal_iterator m_it = internal_iterator();
|
|
};
|
|
|
|
/*!
|
|
@brief a mutable random access iterator for the @ref basic_json class
|
|
|
|
@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.
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
class iterator : public const_iterator
|
|
{
|
|
public:
|
|
using base_iterator = const_iterator;
|
|
using pointer = typename basic_json::pointer;
|
|
using reference = typename basic_json::reference;
|
|
|
|
/// default constructor
|
|
iterator() = default;
|
|
|
|
/// constructor for a given JSON instance
|
|
iterator(pointer object) noexcept
|
|
: base_iterator(object)
|
|
{}
|
|
|
|
/// copy constructor
|
|
iterator(const iterator& other) noexcept
|
|
: base_iterator(other)
|
|
{}
|
|
|
|
/// copy assignment
|
|
iterator& operator=(iterator other) noexcept(
|
|
std::is_nothrow_move_constructible<pointer>::value and
|
|
std::is_nothrow_move_assignable<pointer>::value and
|
|
std::is_nothrow_move_constructible<internal_iterator>::value and
|
|
std::is_nothrow_move_assignable<internal_iterator>::value
|
|
)
|
|
{
|
|
base_iterator::operator=(other);
|
|
return *this;
|
|
}
|
|
|
|
/// return a reference to the value pointed to by the iterator
|
|
reference operator*()
|
|
{
|
|
return const_cast<reference>(base_iterator::operator*());
|
|
}
|
|
|
|
/// dereference the iterator
|
|
pointer operator->()
|
|
{
|
|
return const_cast<pointer>(base_iterator::operator->());
|
|
}
|
|
|
|
/// post-increment (it++)
|
|
iterator operator++(int)
|
|
{
|
|
iterator result = *this;
|
|
base_iterator::operator++();
|
|
return result;
|
|
}
|
|
|
|
/// pre-increment (++it)
|
|
iterator& operator++()
|
|
{
|
|
base_iterator::operator++();
|
|
return *this;
|
|
}
|
|
|
|
/// post-decrement (it--)
|
|
iterator operator--(int)
|
|
{
|
|
iterator result = *this;
|
|
base_iterator::operator--();
|
|
return result;
|
|
}
|
|
|
|
/// pre-decrement (--it)
|
|
iterator& operator--()
|
|
{
|
|
base_iterator::operator--();
|
|
return *this;
|
|
}
|
|
|
|
/// add to iterator
|
|
iterator& operator+=(difference_type i)
|
|
{
|
|
base_iterator::operator+=(i);
|
|
return *this;
|
|
}
|
|
|
|
/// subtract from iterator
|
|
iterator& operator-=(difference_type i)
|
|
{
|
|
base_iterator::operator-=(i);
|
|
return *this;
|
|
}
|
|
|
|
/// add to iterator
|
|
iterator operator+(difference_type i)
|
|
{
|
|
auto result = *this;
|
|
result += i;
|
|
return result;
|
|
}
|
|
|
|
/// subtract from iterator
|
|
iterator operator-(difference_type i)
|
|
{
|
|
auto result = *this;
|
|
result -= i;
|
|
return result;
|
|
}
|
|
|
|
difference_type operator-(const iterator& other) const
|
|
{
|
|
return base_iterator::operator-(other);
|
|
}
|
|
|
|
/// access to successor
|
|
reference operator[](difference_type n) const
|
|
{
|
|
return const_cast<reference>(base_iterator::operator[](n));
|
|
}
|
|
|
|
/// return the value of an iterator
|
|
reference value() const
|
|
{
|
|
return const_cast<reference>(base_iterator::value());
|
|
}
|
|
};
|
|
|
|
/*!
|
|
@brief a template for a reverse iterator class
|
|
|
|
@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).
|
|
|
|
@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).
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template<typename Base>
|
|
class json_reverse_iterator : public std::reverse_iterator<Base>
|
|
{
|
|
public:
|
|
/// shortcut to the reverse iterator adaptor
|
|
using base_iterator = std::reverse_iterator<Base>;
|
|
/// 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)
|
|
: base_iterator(it)
|
|
{}
|
|
|
|
/// create reverse iterator from base class
|
|
json_reverse_iterator(const base_iterator& it)
|
|
: base_iterator(it)
|
|
{}
|
|
|
|
/// 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);
|
|
}
|
|
|
|
/// pre-decrement (--it)
|
|
json_reverse_iterator& operator--()
|
|
{
|
|
base_iterator::operator--();
|
|
return *this;
|
|
}
|
|
|
|
/// add to iterator
|
|
json_reverse_iterator& operator+=(difference_type i)
|
|
{
|
|
base_iterator::operator+=(i);
|
|
return *this;
|
|
}
|
|
|
|
/// add to iterator
|
|
json_reverse_iterator operator+(difference_type i) const
|
|
{
|
|
auto result = *this;
|
|
result += i;
|
|
return result;
|
|
}
|
|
|
|
/// subtract from iterator
|
|
json_reverse_iterator operator-(difference_type i) const
|
|
{
|
|
auto result = *this;
|
|
result -= i;
|
|
return result;
|
|
}
|
|
|
|
/// return difference
|
|
difference_type operator-(const json_reverse_iterator& other) const
|
|
{
|
|
return this->base() - other.base();
|
|
}
|
|
|
|
/// access to successor
|
|
reference operator[](difference_type n) const
|
|
{
|
|
return *(this->operator+(n));
|
|
}
|
|
|
|
/// return the key of an object iterator
|
|
typename object_t::key_type key() const
|
|
{
|
|
auto it = --this->base();
|
|
return it.key();
|
|
}
|
|
|
|
/// return the value of an iterator
|
|
reference value() const
|
|
{
|
|
auto it = --this->base();
|
|
return it.operator * ();
|
|
}
|
|
};
|
|
|
|
|
|
private:
|
|
//////////////////////
|
|
// lexer and parser //
|
|
//////////////////////
|
|
|
|
/*!
|
|
@brief lexical analysis
|
|
|
|
This class organizes the lexical analysis during JSON deserialization. The
|
|
core of it is a scanner generated by re2c <http://re2c.org> that processes
|
|
a buffer and recognizes tokens according to RFC 7159.
|
|
*/
|
|
class lexer
|
|
{
|
|
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_number, ///< a number -- use get_number() 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
|
|
};
|
|
|
|
/// the char type to use in the lexer
|
|
using lexer_char_t = unsigned char;
|
|
|
|
/// constructor with a given buffer
|
|
explicit lexer(const string_t& s) noexcept
|
|
: m_stream(nullptr), m_buffer(s)
|
|
{
|
|
m_content = reinterpret_cast<const lexer_char_t*>(s.c_str());
|
|
assert(m_content != nullptr);
|
|
m_start = m_cursor = m_content;
|
|
m_limit = m_content + s.size();
|
|
}
|
|
|
|
/// constructor with a given stream
|
|
explicit lexer(std::istream* s) noexcept
|
|
: m_stream(s), m_buffer()
|
|
{
|
|
assert(m_stream != nullptr);
|
|
getline(*m_stream, m_buffer);
|
|
m_content = reinterpret_cast<const lexer_char_t*>(m_buffer.c_str());
|
|
assert(m_content != nullptr);
|
|
m_start = m_cursor = m_content;
|
|
m_limit = m_content + m_buffer.size();
|
|
}
|
|
|
|
/// default constructor
|
|
lexer() = default;
|
|
|
|
// switch off unwanted functions
|
|
lexer(const lexer&) = delete;
|
|
lexer operator=(const lexer&) = delete;
|
|
|
|
/*!
|
|
@brief create a string from a Unicode code point
|
|
|
|
@param[in] codepoint1 the code point (can be high surrogate)
|
|
@param[in] codepoint2 the code point (can be low surrogate or 0)
|
|
|
|
@return string representation of the code point
|
|
|
|
@throw std::out_of_range if code point is >0x10ffff; example: `"code
|
|
points above 0x10FFFF are invalid"`
|
|
@throw std::invalid_argument if the low surrogate is invalid; example:
|
|
`""missing or wrong low surrogate""`
|
|
|
|
@see <http://en.wikipedia.org/wiki/UTF-8#Sample_code>
|
|
*/
|
|
static string_t to_unicode(const std::size_t codepoint1,
|
|
const std::size_t codepoint2 = 0)
|
|
{
|
|
string_t result;
|
|
|
|
// calculate the codepoint from the given code points
|
|
std::size_t codepoint = codepoint1;
|
|
|
|
// check if codepoint1 is a high surrogate
|
|
if (codepoint1 >= 0xD800 and codepoint1 <= 0xDBFF)
|
|
{
|
|
// check if codepoint2 is a low surrogate
|
|
if (codepoint2 >= 0xDC00 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
|
|
{
|
|
throw std::invalid_argument("missing or wrong low surrogate");
|
|
}
|
|
}
|
|
|
|
if (codepoint < 0x80)
|
|
{
|
|
// 1-byte characters: 0xxxxxxx (ASCII)
|
|
result.append(1, static_cast<typename string_t::value_type>(codepoint));
|
|
}
|
|
else if (codepoint <= 0x7ff)
|
|
{
|
|
// 2-byte characters: 110xxxxx 10xxxxxx
|
|
result.append(1, static_cast<typename string_t::value_type>(0xC0 | ((codepoint >> 6) & 0x1F)));
|
|
result.append(1, static_cast<typename string_t::value_type>(0x80 | (codepoint & 0x3F)));
|
|
}
|
|
else if (codepoint <= 0xffff)
|
|
{
|
|
// 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx
|
|
result.append(1, static_cast<typename string_t::value_type>(0xE0 | ((codepoint >> 12) & 0x0F)));
|
|
result.append(1, static_cast<typename string_t::value_type>(0x80 | ((codepoint >> 6) & 0x3F)));
|
|
result.append(1, static_cast<typename string_t::value_type>(0x80 | (codepoint & 0x3F)));
|
|
}
|
|
else if (codepoint <= 0x10ffff)
|
|
{
|
|
// 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
|
|
result.append(1, static_cast<typename string_t::value_type>(0xF0 | ((codepoint >> 18) & 0x07)));
|
|
result.append(1, static_cast<typename string_t::value_type>(0x80 | ((codepoint >> 12) & 0x3F)));
|
|
result.append(1, static_cast<typename string_t::value_type>(0x80 | ((codepoint >> 6) & 0x3F)));
|
|
result.append(1, static_cast<typename string_t::value_type>(0x80 | (codepoint & 0x3F)));
|
|
}
|
|
else
|
|
{
|
|
throw std::out_of_range("code points above 0x10FFFF are invalid");
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/// return name of values of type token_type (only used for errors)
|
|
static std::string token_type_name(token_type t)
|
|
{
|
|
switch (t)
|
|
{
|
|
case token_type::uninitialized:
|
|
return "<uninitialized>";
|
|
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 token_type::value_number:
|
|
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 "<parse error>";
|
|
case token_type::end_of_input:
|
|
return "end of input";
|
|
default:
|
|
{
|
|
// catch non-enum values
|
|
return "unknown token"; // LCOV_EXCL_LINE
|
|
}
|
|
}
|
|
}
|
|
|
|
/*!
|
|
This function implements a scanner for JSON. It is specified using
|
|
regular expressions that try to follow RFC 7159 as close as possible.
|
|
These regular expressions are then translated into a deterministic
|
|
finite automaton (DFA) by the tool re2c <http://re2c.org>. As a result,
|
|
the translated code for this function consists of a large block of code
|
|
with goto jumps.
|
|
|
|
@return the class of the next token read from the buffer
|
|
*/
|
|
token_type scan() noexcept
|
|
{
|
|
// pointer for backtracking information
|
|
m_marker = nullptr;
|
|
|
|
// remember the begin of the token
|
|
m_start = m_cursor;
|
|
assert(m_start != nullptr);
|
|
|
|
/*!re2c
|
|
re2c:define:YYCTYPE = lexer_char_t;
|
|
re2c:define:YYCURSOR = m_cursor;
|
|
re2c:define:YYLIMIT = m_limit;
|
|
re2c:define:YYMARKER = m_marker;
|
|
re2c:define:YYFILL = "yyfill(); // LCOV_EXCL_LINE";
|
|
re2c:yyfill:parameter = 0;
|
|
re2c:indent:string = " ";
|
|
re2c:indent:top = 1;
|
|
re2c:labelprefix = "basic_json_parser_";
|
|
|
|
// ignore whitespace
|
|
ws = [ \t\n\r]+;
|
|
ws { return scan(); }
|
|
|
|
// ignore byte-order-mark
|
|
bom = "\xEF\xBB\xBF";
|
|
bom { return scan(); }
|
|
|
|
// structural characters
|
|
"[" { return token_type::begin_array; }
|
|
"]" { return token_type::end_array; }
|
|
"{" { return token_type::begin_object; }
|
|
"}" { return token_type::end_object; }
|
|
"," { return token_type::value_separator; }
|
|
":" { return token_type::name_separator; }
|
|
|
|
// literal names
|
|
"null" { return token_type::literal_null; }
|
|
"true" { return token_type::literal_true; }
|
|
"false" { return token_type::literal_false; }
|
|
|
|
// number
|
|
decimal_point = [.];
|
|
digit = [0-9];
|
|
digit_1_9 = [1-9];
|
|
e = [eE];
|
|
minus = [-];
|
|
plus = [+];
|
|
zero = [0];
|
|
exp = e (minus|plus)? digit+;
|
|
frac = decimal_point digit+;
|
|
int = (zero|digit_1_9 digit*);
|
|
number = minus? int frac? exp?;
|
|
number { return token_type::value_number; }
|
|
|
|
// string
|
|
quotation_mark = [\"];
|
|
escape = [\\];
|
|
unescaped = [^\"\\\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F];
|
|
single_escaped = [\"\\/bfnrt];
|
|
unicode_escaped = [u][0-9a-fA-F]{4};
|
|
escaped = escape (single_escaped | unicode_escaped);
|
|
char = unescaped | escaped;
|
|
string = quotation_mark char* quotation_mark;
|
|
string { return token_type::value_string; }
|
|
|
|
// end of file
|
|
'\000' { return token_type::end_of_input; }
|
|
|
|
// anything else is an error
|
|
. { return token_type::parse_error; }
|
|
*/
|
|
|
|
}
|
|
|
|
/// append data from the stream to the internal buffer
|
|
void yyfill() noexcept
|
|
{
|
|
if (m_stream == nullptr or not * m_stream)
|
|
{
|
|
return;
|
|
}
|
|
|
|
const ssize_t offset_start = m_start - m_content;
|
|
const ssize_t offset_marker = m_marker - m_start;
|
|
const ssize_t offset_cursor = m_cursor - m_start;
|
|
|
|
m_buffer.erase(0, static_cast<size_t>(offset_start));
|
|
std::string line;
|
|
assert(m_stream != nullptr);
|
|
std::getline(*m_stream, line);
|
|
m_buffer += "\n" + line; // add line with newline symbol
|
|
|
|
m_content = reinterpret_cast<const lexer_char_t*>(m_buffer.c_str());
|
|
assert(m_content != nullptr);
|
|
m_start = m_content;
|
|
m_marker = m_start + offset_marker;
|
|
m_cursor = m_start + offset_cursor;
|
|
m_limit = m_start + m_buffer.size() - 1;
|
|
}
|
|
|
|
/// return string representation of last read token
|
|
string_t get_token() const noexcept
|
|
{
|
|
assert(m_start != nullptr);
|
|
return string_t(reinterpret_cast<typename string_t::const_pointer>(m_start),
|
|
static_cast<size_t>(m_cursor - m_start));
|
|
}
|
|
|
|
/*!
|
|
@brief return string value for string tokens
|
|
|
|
The function iterates the characters between the opening and closing
|
|
quotes of the string value. The complete string is the range
|
|
[m_start,m_cursor). Consequently, we iterate from m_start+1 to
|
|
m_cursor-1.
|
|
|
|
We differentiate two cases:
|
|
|
|
1. Escaped characters. In this case, a new character is constructed
|
|
according to the nature of the escape. Some escapes create new
|
|
characters (e.g., @c "\\n" is replaced by @c "\n"), some are copied
|
|
as is (e.g., @c "\\\\"). Furthermore, Unicode escapes of the shape
|
|
@c "\\uxxxx" need special care. In this case, to_unicode takes care
|
|
of the construction of the values.
|
|
2. Unescaped characters are copied as is.
|
|
|
|
@return string value of current token without opening and closing quotes
|
|
@throw std::out_of_range if to_unicode fails
|
|
*/
|
|
string_t get_string() const
|
|
{
|
|
string_t result;
|
|
result.reserve(static_cast<size_t>(m_cursor - m_start - 2));
|
|
|
|
// iterate the result between the quotes
|
|
for (const lexer_char_t* i = m_start + 1; i < m_cursor - 1; ++i)
|
|
{
|
|
// process escaped characters
|
|
if (*i == '\\')
|
|
{
|
|
// read next character
|
|
++i;
|
|
|
|
switch (*i)
|
|
{
|
|
// the default escapes
|
|
case 't':
|
|
{
|
|
result += "\t";
|
|
break;
|
|
}
|
|
case 'b':
|
|
{
|
|
result += "\b";
|
|
break;
|
|
}
|
|
case 'f':
|
|
{
|
|
result += "\f";
|
|
break;
|
|
}
|
|
case 'n':
|
|
{
|
|
result += "\n";
|
|
break;
|
|
}
|
|
case 'r':
|
|
{
|
|
result += "\r";
|
|
break;
|
|
}
|
|
case '\\':
|
|
{
|
|
result += "\\";
|
|
break;
|
|
}
|
|
case '/':
|
|
{
|
|
result += "/";
|
|
break;
|
|
}
|
|
case '"':
|
|
{
|
|
result += "\"";
|
|
break;
|
|
}
|
|
|
|
// unicode
|
|
case 'u':
|
|
{
|
|
// get code xxxx from uxxxx
|
|
auto codepoint = std::strtoul(std::string(reinterpret_cast<typename string_t::const_pointer>(i + 1),
|
|
4).c_str(), nullptr, 16);
|
|
|
|
// check if codepoint is a high surrogate
|
|
if (codepoint >= 0xD800 and codepoint <= 0xDBFF)
|
|
{
|
|
// make sure there is a subsequent unicode
|
|
if ((i + 6 >= m_limit) or * (i + 5) != '\\' or * (i + 6) != 'u')
|
|
{
|
|
throw std::invalid_argument("missing low surrogate");
|
|
}
|
|
|
|
// get code yyyy from uxxxx\uyyyy
|
|
auto codepoint2 = std::strtoul(std::string(reinterpret_cast<typename string_t::const_pointer>
|
|
(i + 7), 4).c_str(), nullptr, 16);
|
|
result += to_unicode(codepoint, codepoint2);
|
|
// skip the next 10 characters (xxxx\uyyyy)
|
|
i += 10;
|
|
}
|
|
else
|
|
{
|
|
// add unicode character(s)
|
|
result += to_unicode(codepoint);
|
|
// skip the next four characters (xxxx)
|
|
i += 4;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// all other characters are just copied to the end of the
|
|
// string
|
|
result.append(1, static_cast<typename string_t::value_type>(*i));
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief return number value for number tokens
|
|
|
|
This function translates the last token into a floating point number.
|
|
The pointer m_start points to the beginning of the parsed number. We
|
|
pass this pointer to std::strtod which sets endptr to the first
|
|
character past the converted number. If this pointer is not the same as
|
|
m_cursor, then either more or less characters have been used during the
|
|
comparison. This can happen for inputs like "01" which will be treated
|
|
like number 0 followed by number 1.
|
|
|
|
@return the result of the number conversion or NAN if the conversion
|
|
read past the current token. The latter case needs to be treated by the
|
|
caller function.
|
|
|
|
@throw std::range_error if passed value is out of range
|
|
*/
|
|
long double get_number() const
|
|
{
|
|
// conversion
|
|
typename string_t::value_type* endptr;
|
|
assert(m_start != nullptr);
|
|
const auto float_val = std::strtold(reinterpret_cast<typename string_t::const_pointer>(m_start),
|
|
&endptr);
|
|
|
|
// return float_val if the whole number was translated and NAN
|
|
// otherwise
|
|
return (reinterpret_cast<lexer_char_t*>(endptr) == m_cursor) ? float_val : NAN;
|
|
}
|
|
|
|
private:
|
|
/// optional input stream
|
|
std::istream* m_stream = nullptr;
|
|
/// the buffer
|
|
string_t m_buffer;
|
|
/// the buffer pointer
|
|
const lexer_char_t* m_content = nullptr;
|
|
/// pointer to the beginning of the current symbol
|
|
const lexer_char_t* m_start = nullptr;
|
|
/// pointer for backtracking information
|
|
const lexer_char_t* m_marker = nullptr;
|
|
/// pointer to the current symbol
|
|
const lexer_char_t* m_cursor = nullptr;
|
|
/// pointer to the end of the buffer
|
|
const lexer_char_t* m_limit = nullptr;
|
|
};
|
|
|
|
/*!
|
|
@brief syntax analysis
|
|
|
|
This class implements a recursive decent parser.
|
|
*/
|
|
class parser
|
|
{
|
|
public:
|
|
/// constructor for strings
|
|
parser(const string_t& s, parser_callback_t cb = nullptr)
|
|
: callback(cb), m_lexer(s)
|
|
{
|
|
// read first token
|
|
get_token();
|
|
}
|
|
|
|
/// a parser reading from an input stream
|
|
parser(std::istream& _is, parser_callback_t cb = nullptr)
|
|
: callback(cb), m_lexer(&_is)
|
|
{
|
|
// read first token
|
|
get_token();
|
|
}
|
|
|
|
/// public parser interface
|
|
basic_json parse()
|
|
{
|
|
basic_json result = parse_internal(true);
|
|
|
|
expect(lexer::token_type::end_of_input);
|
|
|
|
// 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() : result;
|
|
}
|
|
|
|
private:
|
|
/// the actual parser
|
|
basic_json parse_internal(bool keep)
|
|
{
|
|
auto result = basic_json(value_t::discarded);
|
|
|
|
switch (last_token)
|
|
{
|
|
case lexer::token_type::begin_object:
|
|
{
|
|
if (keep and (not callback or (keep = callback(depth++, parse_event_t::object_start, result))))
|
|
{
|
|
// explicitly set result to object to cope with {}
|
|
result.m_type = value_t::object;
|
|
result.m_value = json_value(value_t::object);
|
|
}
|
|
|
|
// read next token
|
|
get_token();
|
|
|
|
// closing } -> we are done
|
|
if (last_token == lexer::token_type::end_object)
|
|
{
|
|
get_token();
|
|
if (keep and callback and not callback(--depth, parse_event_t::object_end, result))
|
|
{
|
|
result = basic_json(value_t::discarded);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
// no comma is expected here
|
|
unexpect(lexer::token_type::value_separator);
|
|
|
|
// otherwise: parse key-value pairs
|
|
do
|
|
{
|
|
// ugly, but could be fixed with loop reorganization
|
|
if (last_token == lexer::token_type::value_separator)
|
|
{
|
|
get_token();
|
|
}
|
|
|
|
// store key
|
|
expect(lexer::token_type::value_string);
|
|
const auto key = m_lexer.get_string();
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
// parse separator (:)
|
|
get_token();
|
|
expect(lexer::token_type::name_separator);
|
|
|
|
// 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);
|
|
}
|
|
}
|
|
while (last_token == lexer::token_type::value_separator);
|
|
|
|
// closing }
|
|
expect(lexer::token_type::end_object);
|
|
get_token();
|
|
if (keep and callback and not callback(--depth, parse_event_t::object_end, result))
|
|
{
|
|
result = basic_json(value_t::discarded);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
case lexer::token_type::begin_array:
|
|
{
|
|
if (keep and (not callback or (keep = callback(depth++, parse_event_t::array_start, result))))
|
|
{
|
|
// explicitly set result to object to cope with []
|
|
result.m_type = value_t::array;
|
|
result.m_value = json_value(value_t::array);
|
|
}
|
|
|
|
// read next token
|
|
get_token();
|
|
|
|
// closing ] -> we are done
|
|
if (last_token == lexer::token_type::end_array)
|
|
{
|
|
get_token();
|
|
if (callback and not callback(--depth, parse_event_t::array_end, result))
|
|
{
|
|
result = basic_json(value_t::discarded);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
// no comma is expected here
|
|
unexpect(lexer::token_type::value_separator);
|
|
|
|
// otherwise: parse values
|
|
do
|
|
{
|
|
// ugly, but could be fixed with loop reorganization
|
|
if (last_token == lexer::token_type::value_separator)
|
|
{
|
|
get_token();
|
|
}
|
|
|
|
// parse value
|
|
auto value = parse_internal(keep);
|
|
if (keep and not value.is_discarded())
|
|
{
|
|
result.push_back(std::move(value));
|
|
}
|
|
}
|
|
while (last_token == lexer::token_type::value_separator);
|
|
|
|
// closing ]
|
|
expect(lexer::token_type::end_array);
|
|
get_token();
|
|
if (keep and callback and not callback(--depth, parse_event_t::array_end, result))
|
|
{
|
|
result = basic_json(value_t::discarded);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
case lexer::token_type::literal_null:
|
|
{
|
|
get_token();
|
|
result.m_type = value_t::null;
|
|
break;
|
|
}
|
|
|
|
case lexer::token_type::value_string:
|
|
{
|
|
const auto s = m_lexer.get_string();
|
|
get_token();
|
|
result = basic_json(s);
|
|
break;
|
|
}
|
|
|
|
case lexer::token_type::literal_true:
|
|
{
|
|
get_token();
|
|
result.m_type = value_t::boolean;
|
|
result.m_value = true;
|
|
break;
|
|
}
|
|
|
|
case lexer::token_type::literal_false:
|
|
{
|
|
get_token();
|
|
result.m_type = value_t::boolean;
|
|
result.m_value = false;
|
|
break;
|
|
}
|
|
|
|
case lexer::token_type::value_number:
|
|
{
|
|
auto float_val = m_lexer.get_number();
|
|
|
|
// NAN is returned if token could not be translated
|
|
// completely
|
|
if (std::isnan(float_val))
|
|
{
|
|
throw std::invalid_argument(std::string("parse error - ") +
|
|
m_lexer.get_token() + " is not a number");
|
|
}
|
|
|
|
get_token();
|
|
|
|
// check if conversion loses precision
|
|
const auto int_val = static_cast<number_integer_t>(float_val);
|
|
if (approx(float_val, static_cast<long double>(int_val)))
|
|
{
|
|
// we would not lose precision -> return int
|
|
result.m_type = value_t::number_integer;
|
|
result.m_value = int_val;
|
|
}
|
|
else
|
|
{
|
|
// we would lose precision -> return float
|
|
result.m_type = value_t::number_float;
|
|
result.m_value = static_cast<number_float_t>(float_val);
|
|
}
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
// the last token was unexpected
|
|
unexpect(last_token);
|
|
}
|
|
}
|
|
|
|
if (keep and callback and not callback(depth, parse_event_t::value, result))
|
|
{
|
|
result = basic_json(value_t::discarded);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// get next token from lexer
|
|
typename lexer::token_type get_token()
|
|
{
|
|
last_token = m_lexer.scan();
|
|
return last_token;
|
|
}
|
|
|
|
void expect(typename lexer::token_type t) const
|
|
{
|
|
if (t != last_token)
|
|
{
|
|
std::string error_msg = "parse error - unexpected ";
|
|
error_msg += (last_token == lexer::token_type::parse_error ? ("'" + m_lexer.get_token() + "'") :
|
|
lexer::token_type_name(last_token));
|
|
error_msg += "; expected " + lexer::token_type_name(t);
|
|
throw std::invalid_argument(error_msg);
|
|
}
|
|
}
|
|
|
|
void unexpect(typename lexer::token_type t) const
|
|
{
|
|
if (t == last_token)
|
|
{
|
|
std::string error_msg = "parse error - unexpected ";
|
|
error_msg += (last_token == lexer::token_type::parse_error ? ("'" + m_lexer.get_token() + "'") :
|
|
lexer::token_type_name(last_token));
|
|
throw std::invalid_argument(error_msg);
|
|
}
|
|
}
|
|
|
|
private:
|
|
/// current level of recursion
|
|
int depth = 0;
|
|
/// callback function
|
|
parser_callback_t callback;
|
|
/// the type of the last read token
|
|
typename lexer::token_type last_token = lexer::token_type::uninitialized;
|
|
/// the lexer
|
|
lexer m_lexer;
|
|
};
|
|
};
|
|
|
|
|
|
/////////////
|
|
// presets //
|
|
/////////////
|
|
|
|
/*!
|
|
@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<>;
|
|
}
|
|
|
|
|
|
/////////////////////////
|
|
// nonmember functions //
|
|
/////////////////////////
|
|
|
|
// specialization of std::swap, and std::hash
|
|
namespace std
|
|
{
|
|
/*!
|
|
@brief exchanges the values of two JSON objects
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
template <>
|
|
inline void swap(nlohmann::json& j1,
|
|
nlohmann::json& j2) noexcept(
|
|
is_nothrow_move_constructible<nlohmann::json>::value and
|
|
is_nothrow_move_assignable<nlohmann::json>::value
|
|
)
|
|
{
|
|
j1.swap(j2);
|
|
}
|
|
|
|
/// hash value for JSON objects
|
|
template <>
|
|
struct hash<nlohmann::json>
|
|
{
|
|
/*!
|
|
@brief return a hash value for a JSON object
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
std::size_t operator()(const nlohmann::json& j) const
|
|
{
|
|
// a naive hashing via the string representation
|
|
const auto& h = hash<nlohmann::json::string_t>();
|
|
return h(j.dump());
|
|
}
|
|
};
|
|
}
|
|
|
|
/*!
|
|
@brief user-defined string literal for JSON values
|
|
|
|
This operator implements a user-defined string literal for JSON objects. It can
|
|
be used by adding \p "_json" to a string literal and returns a JSON object if
|
|
no parse error occurred.
|
|
|
|
@param[in] s a string representation of a JSON object
|
|
@return a JSON object
|
|
|
|
@since version 1.0.0
|
|
*/
|
|
inline nlohmann::json operator "" _json(const char* s, std::size_t)
|
|
{
|
|
return nlohmann::json::parse(reinterpret_cast<const nlohmann::json::string_t::value_type*>(s));
|
|
}
|
|
|
|
#endif
|