1011 lines
34 KiB
C++
1011 lines
34 KiB
C++
#pragma once
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#include <algorithm> // all_of
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#include <cassert> // assert
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#include <cctype> // isdigit
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#include <numeric> // accumulate
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#include <string> // string
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#include <utility> // move
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#include <vector> // vector
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#include <nlohmann/detail/exceptions.hpp>
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#include <nlohmann/detail/macro_scope.hpp>
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#include <nlohmann/detail/value_t.hpp>
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namespace nlohmann
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{
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template<typename BasicJsonType>
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class json_pointer
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{
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// allow basic_json to access private members
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NLOHMANN_BASIC_JSON_TPL_DECLARATION
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friend class basic_json;
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public:
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/*!
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@brief create JSON pointer
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Create a JSON pointer according to the syntax described in
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[Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3).
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@param[in] s string representing the JSON pointer; if omitted, the empty
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string is assumed which references the whole JSON value
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@throw parse_error.107 if the given JSON pointer @a s is nonempty and does
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not begin with a slash (`/`); see example below
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@throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s is
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not followed by `0` (representing `~`) or `1` (representing `/`); see
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example below
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@liveexample{The example shows the construction several valid JSON pointers
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as well as the exceptional behavior.,json_pointer}
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@since version 2.0.0
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*/
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explicit json_pointer(const std::string& s = "")
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: reference_tokens(split(s))
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{}
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/*!
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@brief return a string representation of the JSON pointer
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@invariant For each JSON pointer `ptr`, it holds:
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@code {.cpp}
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ptr == json_pointer(ptr.to_string());
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@endcode
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@return a string representation of the JSON pointer
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@liveexample{The example shows the result of `to_string`.,json_pointer__to_string}
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@since version 2.0.0
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*/
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std::string to_string() const
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{
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return std::accumulate(reference_tokens.begin(), reference_tokens.end(),
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std::string{},
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[](const std::string & a, const std::string & b)
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{
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return a + "/" + escape(b);
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});
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}
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/// @copydoc to_string()
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operator std::string() const
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{
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return to_string();
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}
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/*!
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@brief append another JSON pointer at the end of this JSON pointer
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@param[in] ptr JSON pointer to append
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@return JSON pointer with @a ptr appended
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@liveexample{The example shows the usage of `operator/=`.,json_pointer__operator_add}
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@complexity Linear in the length of @a ptr.
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@sa @ref operator/=(std::string) to append a reference token
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@sa @ref operator/=(std::size_t) to append an array index
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@sa @ref operator/(const json_pointer&, const json_pointer&) for a binary operator
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@since version 3.6.0
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*/
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json_pointer& operator/=(const json_pointer& ptr)
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{
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reference_tokens.insert(reference_tokens.end(),
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ptr.reference_tokens.begin(),
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ptr.reference_tokens.end());
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return *this;
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}
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/*!
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@brief append an unescaped reference token at the end of this JSON pointer
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@param[in] token reference token to append
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@return JSON pointer with @a token appended without escaping @a token
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@liveexample{The example shows the usage of `operator/=`.,json_pointer__operator_add}
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@complexity Amortized constant.
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@sa @ref operator/=(const json_pointer&) to append a JSON pointer
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@sa @ref operator/=(std::size_t) to append an array index
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@sa @ref operator/(const json_pointer&, std::size_t) for a binary operator
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@since version 3.6.0
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*/
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json_pointer& operator/=(std::string token)
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{
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push_back(std::move(token));
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return *this;
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}
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/*!
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@brief append an array index at the end of this JSON pointer
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@param[in] array_index array index ot append
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@return JSON pointer with @a array_index appended
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@liveexample{The example shows the usage of `operator/=`.,json_pointer__operator_add}
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@complexity Amortized constant.
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@sa @ref operator/=(const json_pointer&) to append a JSON pointer
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@sa @ref operator/=(std::string) to append a reference token
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@sa @ref operator/(const json_pointer&, std::string) for a binary operator
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@since version 3.6.0
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*/
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json_pointer& operator/=(std::size_t array_index)
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{
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return *this /= std::to_string(array_index);
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}
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/*!
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@brief create a new JSON pointer by appending the right JSON pointer at the end of the left JSON pointer
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@param[in] lhs JSON pointer
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@param[in] rhs JSON pointer
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@return a new JSON pointer with @a rhs appended to @a lhs
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@liveexample{The example shows the usage of `operator/`.,json_pointer__operator_add_binary}
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@complexity Linear in the length of @a lhs and @a rhs.
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@sa @ref operator/=(const json_pointer&) to append a JSON pointer
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@since version 3.6.0
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*/
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friend json_pointer operator/(const json_pointer& lhs,
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const json_pointer& rhs)
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{
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return json_pointer(lhs) /= rhs;
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}
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/*!
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@brief create a new JSON pointer by appending the unescaped token at the end of the JSON pointer
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@param[in] ptr JSON pointer
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@param[in] token reference token
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@return a new JSON pointer with unescaped @a token appended to @a ptr
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@liveexample{The example shows the usage of `operator/`.,json_pointer__operator_add_binary}
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@complexity Linear in the length of @a ptr.
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@sa @ref operator/=(std::string) to append a reference token
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@since version 3.6.0
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*/
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friend json_pointer operator/(const json_pointer& ptr, std::string token)
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{
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return json_pointer(ptr) /= std::move(token);
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}
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/*!
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@brief create a new JSON pointer by appending the array-index-token at the end of the JSON pointer
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@param[in] ptr JSON pointer
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@param[in] array_index array index
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@return a new JSON pointer with @a array_index appended to @a ptr
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@liveexample{The example shows the usage of `operator/`.,json_pointer__operator_add_binary}
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@complexity Linear in the length of @a ptr.
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@sa @ref operator/=(std::size_t) to append an array index
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@since version 3.6.0
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*/
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friend json_pointer operator/(const json_pointer& ptr, std::size_t array_index)
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{
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return json_pointer(ptr) /= array_index;
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}
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/*!
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@brief returns the parent of this JSON pointer
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@return parent of this JSON pointer; in case this JSON pointer is the root,
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the root itself is returned
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@complexity Linear in the length of the JSON pointer.
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@liveexample{The example shows the result of `parent_pointer` for different
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JSON Pointers.,json_pointer__parent_pointer}
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@since version 3.6.0
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*/
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json_pointer parent_pointer() const
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{
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if (empty())
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{
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return *this;
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}
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json_pointer res = *this;
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res.pop_back();
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return res;
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}
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/*!
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@brief remove last reference token
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@pre not `empty()`
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@liveexample{The example shows the usage of `pop_back`.,json_pointer__pop_back}
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@complexity Constant.
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@throw out_of_range.405 if JSON pointer has no parent
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@since version 3.6.0
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*/
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void pop_back()
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{
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if (JSON_HEDLEY_UNLIKELY(empty()))
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{
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JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent"));
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}
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reference_tokens.pop_back();
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}
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/*!
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@brief return last reference token
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@pre not `empty()`
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@return last reference token
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@liveexample{The example shows the usage of `back`.,json_pointer__back}
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@complexity Constant.
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@throw out_of_range.405 if JSON pointer has no parent
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@since version 3.6.0
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*/
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const std::string& back()
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{
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if (JSON_HEDLEY_UNLIKELY(empty()))
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{
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JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent"));
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}
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return reference_tokens.back();
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}
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/*!
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@brief append an unescaped token at the end of the reference pointer
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@param[in] token token to add
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@complexity Amortized constant.
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@liveexample{The example shows the result of `push_back` for different
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JSON Pointers.,json_pointer__push_back}
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@since version 3.6.0
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*/
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void push_back(const std::string& token)
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{
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reference_tokens.push_back(token);
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}
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/// @copydoc push_back(const std::string&)
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void push_back(std::string&& token)
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{
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reference_tokens.push_back(std::move(token));
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}
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/*!
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@brief return whether pointer points to the root document
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@return true iff the JSON pointer points to the root document
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@complexity Constant.
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@exceptionsafety No-throw guarantee: this function never throws exceptions.
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@liveexample{The example shows the result of `empty` for different JSON
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Pointers.,json_pointer__empty}
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@since version 3.6.0
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*/
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bool empty() const noexcept
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{
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return reference_tokens.empty();
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}
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private:
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/*!
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@param[in] s reference token to be converted into an array index
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@return integer representation of @a s
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@throw out_of_range.404 if string @a s could not be converted to an integer
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*/
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static int array_index(const std::string& s)
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{
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std::size_t processed_chars = 0;
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const int res = std::stoi(s, &processed_chars);
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// check if the string was completely read
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if (JSON_HEDLEY_UNLIKELY(processed_chars != s.size()))
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{
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JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + s + "'"));
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}
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return res;
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}
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json_pointer top() const
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{
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if (JSON_HEDLEY_UNLIKELY(empty()))
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{
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JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent"));
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}
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json_pointer result = *this;
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result.reference_tokens = {reference_tokens[0]};
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return result;
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}
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/*!
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@brief create and return a reference to the pointed to value
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@complexity Linear in the number of reference tokens.
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@throw parse_error.109 if array index is not a number
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@throw type_error.313 if value cannot be unflattened
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*/
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BasicJsonType& get_and_create(BasicJsonType& j) const
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{
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using size_type = typename BasicJsonType::size_type;
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auto result = &j;
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// in case no reference tokens exist, return a reference to the JSON value
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// j which will be overwritten by a primitive value
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for (const auto& reference_token : reference_tokens)
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{
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switch (result->type())
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{
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case detail::value_t::null:
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{
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if (reference_token == "0")
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{
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// start a new array if reference token is 0
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result = &result->operator[](0);
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}
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else
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{
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// start a new object otherwise
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result = &result->operator[](reference_token);
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}
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break;
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}
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case detail::value_t::object:
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{
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// create an entry in the object
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result = &result->operator[](reference_token);
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break;
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}
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case detail::value_t::array:
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{
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// create an entry in the array
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JSON_TRY
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{
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result = &result->operator[](static_cast<size_type>(array_index(reference_token)));
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}
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JSON_CATCH(std::invalid_argument&)
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{
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JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number"));
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}
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break;
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}
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/*
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The following code is only reached if there exists a reference
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token _and_ the current value is primitive. In this case, we have
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an error situation, because primitive values may only occur as
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single value; that is, with an empty list of reference tokens.
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*/
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default:
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JSON_THROW(detail::type_error::create(313, "invalid value to unflatten"));
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}
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}
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return *result;
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}
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/*!
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@brief return a reference to the pointed to value
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@note This version does not throw if a value is not present, but tries to
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create nested values instead. For instance, calling this function
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with pointer `"/this/that"` on a null value is equivalent to calling
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`operator[]("this").operator[]("that")` on that value, effectively
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changing the null value to an object.
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@param[in] ptr a JSON value
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@return reference to the JSON value pointed to by the JSON pointer
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@complexity Linear in the length of the JSON pointer.
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@throw parse_error.106 if an array index begins with '0'
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@throw parse_error.109 if an array index was not a number
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@throw out_of_range.404 if the JSON pointer can not be resolved
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*/
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BasicJsonType& get_unchecked(BasicJsonType* ptr) const
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{
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using size_type = typename BasicJsonType::size_type;
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for (const auto& reference_token : reference_tokens)
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{
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// convert null values to arrays or objects before continuing
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if (ptr->is_null())
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{
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// check if reference token is a number
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const bool nums =
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std::all_of(reference_token.begin(), reference_token.end(),
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[](const unsigned char x)
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{
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return std::isdigit(x);
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});
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// change value to array for numbers or "-" or to object otherwise
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*ptr = (nums or reference_token == "-")
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? detail::value_t::array
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: detail::value_t::object;
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}
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switch (ptr->type())
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{
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case detail::value_t::object:
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{
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// use unchecked object access
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ptr = &ptr->operator[](reference_token);
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break;
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}
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case detail::value_t::array:
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{
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// error condition (cf. RFC 6901, Sect. 4)
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if (JSON_HEDLEY_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
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{
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JSON_THROW(detail::parse_error::create(106, 0,
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"array index '" + reference_token +
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"' must not begin with '0'"));
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}
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if (reference_token == "-")
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{
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// explicitly treat "-" as index beyond the end
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ptr = &ptr->operator[](ptr->m_value.array->size());
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}
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else
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{
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// convert array index to number; unchecked access
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JSON_TRY
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{
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ptr = &ptr->operator[](
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static_cast<size_type>(array_index(reference_token)));
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}
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JSON_CATCH(std::invalid_argument&)
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{
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JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number"));
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}
|
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}
|
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break;
|
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}
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default:
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JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'"));
|
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}
|
|
}
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|
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return *ptr;
|
|
}
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|
|
|
/*!
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@throw parse_error.106 if an array index begins with '0'
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@throw parse_error.109 if an array index was not a number
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@throw out_of_range.402 if the array index '-' is used
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@throw out_of_range.404 if the JSON pointer can not be resolved
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*/
|
|
BasicJsonType& get_checked(BasicJsonType* ptr) const
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|
{
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using size_type = typename BasicJsonType::size_type;
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for (const auto& reference_token : reference_tokens)
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|
{
|
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switch (ptr->type())
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|
{
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|
case detail::value_t::object:
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{
|
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// note: at performs range check
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ptr = &ptr->at(reference_token);
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break;
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}
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case detail::value_t::array:
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{
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if (JSON_HEDLEY_UNLIKELY(reference_token == "-"))
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{
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// "-" always fails the range check
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JSON_THROW(detail::out_of_range::create(402,
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"array index '-' (" + std::to_string(ptr->m_value.array->size()) +
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") is out of range"));
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}
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|
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// error condition (cf. RFC 6901, Sect. 4)
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if (JSON_HEDLEY_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
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{
|
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JSON_THROW(detail::parse_error::create(106, 0,
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"array index '" + reference_token +
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"' must not begin with '0'"));
|
|
}
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|
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// note: at performs range check
|
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JSON_TRY
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{
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ptr = &ptr->at(static_cast<size_type>(array_index(reference_token)));
|
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}
|
|
JSON_CATCH(std::invalid_argument&)
|
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{
|
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JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number"));
|
|
}
|
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break;
|
|
}
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|
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default:
|
|
JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'"));
|
|
}
|
|
}
|
|
|
|
return *ptr;
|
|
}
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|
|
/*!
|
|
@brief return a const reference to the pointed to value
|
|
|
|
@param[in] ptr a JSON value
|
|
|
|
@return const reference to the JSON value pointed to by the JSON
|
|
pointer
|
|
|
|
@throw parse_error.106 if an array index begins with '0'
|
|
@throw parse_error.109 if an array index was not a number
|
|
@throw out_of_range.402 if the array index '-' is used
|
|
@throw out_of_range.404 if the JSON pointer can not be resolved
|
|
*/
|
|
const BasicJsonType& get_unchecked(const BasicJsonType* ptr) const
|
|
{
|
|
using size_type = typename BasicJsonType::size_type;
|
|
for (const auto& reference_token : reference_tokens)
|
|
{
|
|
switch (ptr->type())
|
|
{
|
|
case detail::value_t::object:
|
|
{
|
|
// use unchecked object access
|
|
ptr = &ptr->operator[](reference_token);
|
|
break;
|
|
}
|
|
|
|
case detail::value_t::array:
|
|
{
|
|
if (JSON_HEDLEY_UNLIKELY(reference_token == "-"))
|
|
{
|
|
// "-" cannot be used for const access
|
|
JSON_THROW(detail::out_of_range::create(402,
|
|
"array index '-' (" + std::to_string(ptr->m_value.array->size()) +
|
|
") is out of range"));
|
|
}
|
|
|
|
// error condition (cf. RFC 6901, Sect. 4)
|
|
if (JSON_HEDLEY_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
|
|
{
|
|
JSON_THROW(detail::parse_error::create(106, 0,
|
|
"array index '" + reference_token +
|
|
"' must not begin with '0'"));
|
|
}
|
|
|
|
// use unchecked array access
|
|
JSON_TRY
|
|
{
|
|
ptr = &ptr->operator[](
|
|
static_cast<size_type>(array_index(reference_token)));
|
|
}
|
|
JSON_CATCH(std::invalid_argument&)
|
|
{
|
|
JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number"));
|
|
}
|
|
break;
|
|
}
|
|
|
|
default:
|
|
JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'"));
|
|
}
|
|
}
|
|
|
|
return *ptr;
|
|
}
|
|
|
|
/*!
|
|
@throw parse_error.106 if an array index begins with '0'
|
|
@throw parse_error.109 if an array index was not a number
|
|
@throw out_of_range.402 if the array index '-' is used
|
|
@throw out_of_range.404 if the JSON pointer can not be resolved
|
|
*/
|
|
const BasicJsonType& get_checked(const BasicJsonType* ptr) const
|
|
{
|
|
using size_type = typename BasicJsonType::size_type;
|
|
for (const auto& reference_token : reference_tokens)
|
|
{
|
|
switch (ptr->type())
|
|
{
|
|
case detail::value_t::object:
|
|
{
|
|
// note: at performs range check
|
|
ptr = &ptr->at(reference_token);
|
|
break;
|
|
}
|
|
|
|
case detail::value_t::array:
|
|
{
|
|
if (JSON_HEDLEY_UNLIKELY(reference_token == "-"))
|
|
{
|
|
// "-" always fails the range check
|
|
JSON_THROW(detail::out_of_range::create(402,
|
|
"array index '-' (" + std::to_string(ptr->m_value.array->size()) +
|
|
") is out of range"));
|
|
}
|
|
|
|
// error condition (cf. RFC 6901, Sect. 4)
|
|
if (JSON_HEDLEY_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
|
|
{
|
|
JSON_THROW(detail::parse_error::create(106, 0,
|
|
"array index '" + reference_token +
|
|
"' must not begin with '0'"));
|
|
}
|
|
|
|
// note: at performs range check
|
|
JSON_TRY
|
|
{
|
|
ptr = &ptr->at(static_cast<size_type>(array_index(reference_token)));
|
|
}
|
|
JSON_CATCH(std::invalid_argument&)
|
|
{
|
|
JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number"));
|
|
}
|
|
break;
|
|
}
|
|
|
|
default:
|
|
JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'"));
|
|
}
|
|
}
|
|
|
|
return *ptr;
|
|
}
|
|
|
|
/*!
|
|
@throw parse_error.106 if an array index begins with '0'
|
|
@throw parse_error.109 if an array index was not a number
|
|
*/
|
|
bool contains(const BasicJsonType* ptr) const
|
|
{
|
|
using size_type = typename BasicJsonType::size_type;
|
|
for (const auto& reference_token : reference_tokens)
|
|
{
|
|
switch (ptr->type())
|
|
{
|
|
case detail::value_t::object:
|
|
{
|
|
if (not ptr->contains(reference_token))
|
|
{
|
|
// we did not find the key in the object
|
|
return false;
|
|
}
|
|
|
|
ptr = &ptr->operator[](reference_token);
|
|
break;
|
|
}
|
|
|
|
case detail::value_t::array:
|
|
{
|
|
if (JSON_UNLIKELY(reference_token == "-"))
|
|
{
|
|
// "-" always fails the range check
|
|
return false;
|
|
}
|
|
|
|
// error condition (cf. RFC 6901, Sect. 4)
|
|
if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
|
|
{
|
|
JSON_THROW(detail::parse_error::create(106, 0,
|
|
"array index '" + reference_token +
|
|
"' must not begin with '0'"));
|
|
}
|
|
|
|
JSON_TRY
|
|
{
|
|
const auto idx = static_cast<size_type>(array_index(reference_token));
|
|
if (idx >= ptr->size())
|
|
{
|
|
// index out of range
|
|
return false;
|
|
}
|
|
|
|
ptr = &ptr->operator[](idx);
|
|
break;
|
|
}
|
|
JSON_CATCH(std::invalid_argument&)
|
|
{
|
|
JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number"));
|
|
}
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
// we do not expect primitive values if there is still a
|
|
// reference token to process
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
// no reference token left means we found a primitive value
|
|
return true;
|
|
}
|
|
|
|
/*!
|
|
@brief split the string input to reference tokens
|
|
|
|
@note This function is only called by the json_pointer constructor.
|
|
All exceptions below are documented there.
|
|
|
|
@throw parse_error.107 if the pointer is not empty or begins with '/'
|
|
@throw parse_error.108 if character '~' is not followed by '0' or '1'
|
|
*/
|
|
static std::vector<std::string> split(const std::string& reference_string)
|
|
{
|
|
std::vector<std::string> result;
|
|
|
|
// special case: empty reference string -> no reference tokens
|
|
if (reference_string.empty())
|
|
{
|
|
return result;
|
|
}
|
|
|
|
// check if nonempty reference string begins with slash
|
|
if (JSON_HEDLEY_UNLIKELY(reference_string[0] != '/'))
|
|
{
|
|
JSON_THROW(detail::parse_error::create(107, 1,
|
|
"JSON pointer must be empty or begin with '/' - was: '" +
|
|
reference_string + "'"));
|
|
}
|
|
|
|
// extract the reference tokens:
|
|
// - slash: position of the last read slash (or end of string)
|
|
// - start: position after the previous slash
|
|
for (
|
|
// search for the first slash after the first character
|
|
std::size_t slash = reference_string.find_first_of('/', 1),
|
|
// set the beginning of the first reference token
|
|
start = 1;
|
|
// we can stop if start == 0 (if slash == std::string::npos)
|
|
start != 0;
|
|
// set the beginning of the next reference token
|
|
// (will eventually be 0 if slash == std::string::npos)
|
|
start = (slash == std::string::npos) ? 0 : slash + 1,
|
|
// find next slash
|
|
slash = reference_string.find_first_of('/', start))
|
|
{
|
|
// use the text between the beginning of the reference token
|
|
// (start) and the last slash (slash).
|
|
auto reference_token = reference_string.substr(start, slash - start);
|
|
|
|
// check reference tokens are properly escaped
|
|
for (std::size_t pos = reference_token.find_first_of('~');
|
|
pos != std::string::npos;
|
|
pos = reference_token.find_first_of('~', pos + 1))
|
|
{
|
|
assert(reference_token[pos] == '~');
|
|
|
|
// ~ must be followed by 0 or 1
|
|
if (JSON_HEDLEY_UNLIKELY(pos == reference_token.size() - 1 or
|
|
(reference_token[pos + 1] != '0' and
|
|
reference_token[pos + 1] != '1')))
|
|
{
|
|
JSON_THROW(detail::parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'"));
|
|
}
|
|
}
|
|
|
|
// finally, store the reference token
|
|
unescape(reference_token);
|
|
result.push_back(reference_token);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief replace all occurrences of a substring by another string
|
|
|
|
@param[in,out] s the string to manipulate; changed so that all
|
|
occurrences of @a f are replaced with @a t
|
|
@param[in] f the substring to replace with @a t
|
|
@param[in] t the string to replace @a f
|
|
|
|
@pre The search string @a f must not be empty. **This precondition is
|
|
enforced with an assertion.**
|
|
|
|
@since version 2.0.0
|
|
*/
|
|
static void replace_substring(std::string& s, const std::string& f,
|
|
const std::string& t)
|
|
{
|
|
assert(not f.empty());
|
|
for (auto pos = s.find(f); // find first occurrence of f
|
|
pos != std::string::npos; // make sure f was found
|
|
s.replace(pos, f.size(), t), // replace with t, and
|
|
pos = s.find(f, pos + t.size())) // find next occurrence of f
|
|
{}
|
|
}
|
|
|
|
/// escape "~" to "~0" and "/" to "~1"
|
|
static std::string escape(std::string s)
|
|
{
|
|
replace_substring(s, "~", "~0");
|
|
replace_substring(s, "/", "~1");
|
|
return s;
|
|
}
|
|
|
|
/// unescape "~1" to tilde and "~0" to slash (order is important!)
|
|
static void unescape(std::string& s)
|
|
{
|
|
replace_substring(s, "~1", "/");
|
|
replace_substring(s, "~0", "~");
|
|
}
|
|
|
|
/*!
|
|
@param[in] reference_string the reference string to the current value
|
|
@param[in] value the value to consider
|
|
@param[in,out] result the result object to insert values to
|
|
|
|
@note Empty objects or arrays are flattened to `null`.
|
|
*/
|
|
static void flatten(const std::string& reference_string,
|
|
const BasicJsonType& value,
|
|
BasicJsonType& result)
|
|
{
|
|
switch (value.type())
|
|
{
|
|
case detail::value_t::array:
|
|
{
|
|
if (value.m_value.array->empty())
|
|
{
|
|
// flatten empty array as null
|
|
result[reference_string] = nullptr;
|
|
}
|
|
else
|
|
{
|
|
// iterate array and use index as reference string
|
|
for (std::size_t i = 0; i < value.m_value.array->size(); ++i)
|
|
{
|
|
flatten(reference_string + "/" + std::to_string(i),
|
|
value.m_value.array->operator[](i), result);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
case detail::value_t::object:
|
|
{
|
|
if (value.m_value.object->empty())
|
|
{
|
|
// flatten empty object as null
|
|
result[reference_string] = nullptr;
|
|
}
|
|
else
|
|
{
|
|
// iterate object and use keys as reference string
|
|
for (const auto& element : *value.m_value.object)
|
|
{
|
|
flatten(reference_string + "/" + escape(element.first), element.second, result);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
default:
|
|
{
|
|
// add primitive value with its reference string
|
|
result[reference_string] = value;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*!
|
|
@param[in] value flattened JSON
|
|
|
|
@return unflattened JSON
|
|
|
|
@throw parse_error.109 if array index is not a number
|
|
@throw type_error.314 if value is not an object
|
|
@throw type_error.315 if object values are not primitive
|
|
@throw type_error.313 if value cannot be unflattened
|
|
*/
|
|
static BasicJsonType
|
|
unflatten(const BasicJsonType& value)
|
|
{
|
|
if (JSON_HEDLEY_UNLIKELY(not value.is_object()))
|
|
{
|
|
JSON_THROW(detail::type_error::create(314, "only objects can be unflattened"));
|
|
}
|
|
|
|
BasicJsonType result;
|
|
|
|
// iterate the JSON object values
|
|
for (const auto& element : *value.m_value.object)
|
|
{
|
|
if (JSON_HEDLEY_UNLIKELY(not element.second.is_primitive()))
|
|
{
|
|
JSON_THROW(detail::type_error::create(315, "values in object must be primitive"));
|
|
}
|
|
|
|
// assign value to reference pointed to by JSON pointer; Note that if
|
|
// the JSON pointer is "" (i.e., points to the whole value), function
|
|
// get_and_create returns a reference to result itself. An assignment
|
|
// will then create a primitive value.
|
|
json_pointer(element.first).get_and_create(result) = element.second;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*!
|
|
@brief compares two JSON pointers for equality
|
|
|
|
@param[in] lhs JSON pointer to compare
|
|
@param[in] rhs JSON pointer to compare
|
|
@return whether @a lhs is equal to @a rhs
|
|
|
|
@complexity Linear in the length of the JSON pointer
|
|
|
|
@exceptionsafety No-throw guarantee: this function never throws exceptions.
|
|
*/
|
|
friend bool operator==(json_pointer const& lhs,
|
|
json_pointer const& rhs) noexcept
|
|
{
|
|
return lhs.reference_tokens == rhs.reference_tokens;
|
|
}
|
|
|
|
/*!
|
|
@brief compares two JSON pointers for inequality
|
|
|
|
@param[in] lhs JSON pointer to compare
|
|
@param[in] rhs JSON pointer to compare
|
|
@return whether @a lhs is not equal @a rhs
|
|
|
|
@complexity Linear in the length of the JSON pointer
|
|
|
|
@exceptionsafety No-throw guarantee: this function never throws exceptions.
|
|
*/
|
|
friend bool operator!=(json_pointer const& lhs,
|
|
json_pointer const& rhs) noexcept
|
|
{
|
|
return not (lhs == rhs);
|
|
}
|
|
|
|
/// the reference tokens
|
|
std::vector<std::string> reference_tokens;
|
|
};
|
|
} // namespace nlohmann
|