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🔨 moved class json_pointer into separate file #920

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Niels Lohmann 2018-01-28 15:36:56 +01:00
parent e95578f884
commit 1483d39c91
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7 changed files with 1170 additions and 1197 deletions
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9
Makefile
View file

@ -16,6 +16,7 @@ SRCS = develop/json.hpp \
develop/detail/iterators/iteration_proxy.hpp \
develop/detail/iterators/json_reverse_iterator.hpp \
develop/detail/iterators/primitive_iterator.hpp \
develop/detail/json_pointer.hpp \
develop/detail/json_ref.hpp \
develop/detail/macro_scope.hpp \
develop/detail/macro_unscope.hpp \
@ -273,6 +274,14 @@ check-amalgamation:
@diff src/json.hpp src/json.hpp~ || (echo "===================================================================\n Amalgamation required! Please read the contribution guidelines\n in file .github/CONTRIBUTING.md.\n===================================================================" ; mv src/json.hpp~ src/json.hpp ; false)
@mv src/json.hpp~ src/json.hpp
# check if every header in develop includes sufficient headers to be compiled
# individually
check-single-includes:
for x in $(SRCS); do \
echo "#include \"$$x\"\nint main() {}\n" | sed 's|develop/||' > single_include_test.cpp; \
$(CXX) $(CXXFLAGS) -Idevelop -std=c++11 single_include_test.cpp -o single_include_test; \
rm single_include_test.cpp single_include_test; \
done
##########################################################################
# changelog

1
develop/detail/input/binary_reader.hpp
View file

@ -15,6 +15,7 @@
#include <string> // char_traits, string
#include <utility> // make_pair, move
#include "detail/input/input_adapters.hpp"
#include "detail/exceptions.hpp"
#include "detail/macro_scope.hpp"
#include "detail/value_t.hpp"

696
develop/detail/json_pointer.hpp Normal file
View file

@ -0,0 +1,696 @@
#pragma once
#include <cassert> // assert
#include <numeric> // accumulate
#include <string> // string
#include <vector> // vector
#include "detail/macro_scope.hpp"
#include "detail/exceptions.hpp"
#include "detail/value_t.hpp"
namespace nlohmann
{
template<typename BasicJsonType>
class json_pointer
{
// allow basic_json to access private members
NLOHMANN_BASIC_JSON_TPL_DECLARATION
friend class basic_json;
public:
/*!
@brief create JSON pointer
Create a JSON pointer according to the syntax described in
[Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3).
@param[in] s string representing the JSON pointer; if omitted, the empty
string is assumed which references the whole JSON value
@throw parse_error.107 if the given JSON pointer @a s is nonempty and does
not begin with a slash (`/`); see example below
@throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s is
not followed by `0` (representing `~`) or `1` (representing `/`); see
example below
@liveexample{The example shows the construction several valid JSON pointers
as well as the exceptional behavior.,json_pointer}
@since version 2.0.0
*/
explicit json_pointer(const std::string& s = "")
: reference_tokens(split(s))
{}
/*!
@brief return a string representation of the JSON pointer
@invariant For each JSON pointer `ptr`, it holds:
@code {.cpp}
ptr == json_pointer(ptr.to_string());
@endcode
@return a string representation of the JSON pointer
@liveexample{The example shows the result of `to_string`.,
json_pointer__to_string}
@since version 2.0.0
*/
std::string to_string() const noexcept
{
return std::accumulate(reference_tokens.begin(), reference_tokens.end(),
std::string{},
[](const std::string & a, const std::string & b)
{
return a + "/" + escape(b);
});
}
/// @copydoc to_string()
operator std::string() const
{
return to_string();
}
/*!
@param[in] s reference token to be converted into an array index
@return integer representation of @a s
@throw out_of_range.404 if string @a s could not be converted to an integer
*/
static int array_index(const std::string& s)
{
std::size_t processed_chars = 0;
const int res = std::stoi(s, &processed_chars);
// check if the string was completely read
if (JSON_UNLIKELY(processed_chars != s.size()))
{
JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + s + "'"));
}
return res;
}
private:
/*!
@brief remove and return last reference pointer
@throw out_of_range.405 if JSON pointer has no parent
*/
std::string pop_back()
{
if (JSON_UNLIKELY(is_root()))
{
JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent"));
}
auto last = reference_tokens.back();
reference_tokens.pop_back();
return last;
}
/// return whether pointer points to the root document
bool is_root() const
{
return reference_tokens.empty();
}
json_pointer top() const
{
if (JSON_UNLIKELY(is_root()))
{
JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent"));
}
json_pointer result = *this;
result.reference_tokens = {reference_tokens[0]};
return result;
}
/*!
@brief create and return a reference to the pointed to value
@complexity Linear in the number of reference tokens.
@throw parse_error.109 if array index is not a number
@throw type_error.313 if value cannot be unflattened
*/
BasicJsonType& get_and_create(BasicJsonType& j) const
{
using size_type = typename BasicJsonType::size_type;
auto result = &j;
// in case no reference tokens exist, return a reference to the JSON value
// j which will be overwritten by a primitive value
for (const auto& reference_token : reference_tokens)
{
switch (result->m_type)
{
case detail::value_t::null:
{
if (reference_token == "0")
{
// start a new array if reference token is 0
result = &result->operator[](0);
}
else
{
// start a new object otherwise
result = &result->operator[](reference_token);
}
break;
}
case detail::value_t::object:
{
// create an entry in the object
result = &result->operator[](reference_token);
break;
}
case detail::value_t::array:
{
// create an entry in the array
JSON_TRY
{
result = &result->operator[](static_cast<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;
}
/*
The following code is only reached if there exists a reference
token _and_ the current value is primitive. In this case, we have
an error situation, because primitive values may only occur as
single value; that is, with an empty list of reference tokens.
*/
default:
JSON_THROW(detail::type_error::create(313, "invalid value to unflatten"));
}
}
return *result;
}
/*!
@brief return a reference to the pointed to value
@note This version does not throw if a value is not present, but tries to
create nested values instead. For instance, calling this function
with pointer `"/this/that"` on a null value is equivalent to calling
`operator[]("this").operator[]("that")` on that value, effectively
changing the null value to an object.
@param[in] ptr a JSON value
@return reference to the JSON value pointed to by the JSON pointer
@complexity Linear in the length of 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.404 if the JSON pointer can not be resolved
*/
BasicJsonType& get_unchecked(BasicJsonType* ptr) const
{
using size_type = typename BasicJsonType::size_type;
for (const auto& reference_token : reference_tokens)
{
// convert null values to arrays or objects before continuing
if (ptr->m_type == detail::value_t::null)
{
// check if reference token is a number
const bool nums =
std::all_of(reference_token.begin(), reference_token.end(),
[](const char x)
{
return (x >= '0' and x <= '9');
});
// change value to array for numbers or "-" or to object otherwise
*ptr = (nums or reference_token == "-")
? detail::value_t::array
: detail::value_t::object;
}
switch (ptr->m_type)
{
case detail::value_t::object:
{
// use unchecked object access
ptr = &ptr->operator[](reference_token);
break;
}
case detail::value_t::array:
{
// error condition (cf. RFC 6901, Sect. 4)
if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
{
JSON_THROW(detail::parse_error::create(106, 0,
"array index '" + reference_token +
"' must not begin with '0'"));
}
if (reference_token == "-")
{
// explicitly treat "-" as index beyond the end
ptr = &ptr->operator[](ptr->m_value.array->size());
}
else
{
// convert array index to number; unchecked access
JSON_TRY
{
ptr = &ptr->operator[](
static_cast<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
*/
BasicJsonType& get_checked(BasicJsonType* ptr) const
{
using size_type = typename BasicJsonType::size_type;
for (const auto& reference_token : reference_tokens)
{
switch (ptr->m_type)
{
case detail::value_t::object:
{
// note: at performs range check
ptr = &ptr->at(reference_token);
break;
}
case detail::value_t::array:
{
if (JSON_UNLIKELY(reference_token == "-"))
{
// "-" always fails the range check
JSON_THROW(detail::out_of_range::create(402,
"array index '-' (" + std::to_string(ptr->m_value.array->size()) +
") is out of range"));
}
// 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'"));
}
// 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;
}
/*!
@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->m_type)
{
case detail::value_t::object:
{
// use unchecked object access
ptr = &ptr->operator[](reference_token);
break;
}
case detail::value_t::array:
{
if (JSON_UNLIKELY(reference_token == "-"))
{
// "-" cannot be used for const access
JSON_THROW(detail::out_of_range::create(402,
"array index '-' (" + std::to_string(ptr->m_value.array->size()) +
") is out of range"));
}
// 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'"));
}
// 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->m_type)
{
case detail::value_t::object:
{
// note: at performs range check
ptr = &ptr->at(reference_token);
break;
}
case detail::value_t::array:
{
if (JSON_UNLIKELY(reference_token == "-"))
{
// "-" always fails the range check
JSON_THROW(detail::out_of_range::create(402,
"array index '-' (" + std::to_string(ptr->m_value.array->size()) +
") is out of range"));
}
// 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'"));
}
// 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;
}
/*!
@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_UNLIKELY(reference_string[0] != '/'))
{
JSON_THROW(detail::parse_error::create(107, 1,
"JSON pointer must be empty or begin with '/' - was: '" +
reference_string + "'"));
}
// extract the reference tokens:
// - slash: position of the last read slash (or end of string)
// - start: position after the previous slash
for (
// search for the first slash after the first character
std::size_t slash = reference_string.find_first_of('/', 1),
// set the beginning of the first reference token
start = 1;
// we can stop if start == string::npos+1 = 0
start != 0;
// set the beginning of the next reference token
// (will eventually be 0 if slash == std::string::npos)
start = slash + 1,
// find next slash
slash = reference_string.find_first_of('/', start))
{
// use the text between the beginning of the reference token
// (start) and the last slash (slash).
auto reference_token = reference_string.substr(start, slash - start);
// check reference tokens are properly escaped
for (std::size_t pos = reference_token.find_first_of('~');
pos != std::string::npos;
pos = reference_token.find_first_of('~', pos + 1))
{
assert(reference_token[pos] == '~');
// ~ must be followed by 0 or 1
if (JSON_UNLIKELY(pos == reference_token.size() - 1 or
(reference_token[pos + 1] != '0' and
reference_token[pos + 1] != '1')))
{
JSON_THROW(detail::parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'"));
}
}
// 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.m_type)
{
case detail::value_t::array:
{
if (value.m_value.array->empty())
{
// flatten empty array as null
result[reference_string] = nullptr;
}
else
{
// iterate array and use index as reference string
for (std::size_t i = 0; i < value.m_value.array->size(); ++i)
{
flatten(reference_string + "/" + std::to_string(i),
value.m_value.array->operator[](i), result);
}
}
break;
}
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_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_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;
}
friend bool operator==(json_pointer const& lhs,
json_pointer const& rhs) noexcept
{
return (lhs.reference_tokens == rhs.reference_tokens);
}
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;
};
}

3
develop/detail/output/serializer.hpp
View file

@ -9,11 +9,14 @@
#include <cstddef> // size_t, ptrdiff_t
#include <cstdint> // uint8_t
#include <cstdio> // snprintf
#include <iomanip> // setfill
#include <iterator> // next
#include <limits> // numeric_limits
#include <string> // string
#include <sstream> // stringstream
#include <type_traits> // is_same
#include "detail/exceptions.hpp"
#include "detail/conversions/to_chars.hpp"
#include "detail/macro_scope.hpp"
#include "detail/meta.hpp"

728
develop/json.hpp
View file

@ -61,6 +61,7 @@ SOFTWARE.
#include "detail/output/binary_writer.hpp"
#include "detail/output/serializer.hpp"
#include "detail/json_ref.hpp"
#include "detail/json_pointer.hpp"
#include "adl_serializer.hpp"
/*!
@ -70,335 +71,6 @@ SOFTWARE.
*/
namespace nlohmann
{
class json_pointer
{
/// allow basic_json to access private members
NLOHMANN_BASIC_JSON_TPL_DECLARATION
friend class basic_json;
public:
/*!
@brief create JSON pointer
Create a JSON pointer according to the syntax described in
[Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3).
@param[in] s string representing the JSON pointer; if omitted, the empty
string is assumed which references the whole JSON value
@throw parse_error.107 if the given JSON pointer @a s is nonempty and
does not begin with a slash (`/`); see example below
@throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s
is not followed by `0` (representing `~`) or `1` (representing `/`);
see example below
@liveexample{The example shows the construction several valid JSON
pointers as well as the exceptional behavior.,json_pointer}
@since version 2.0.0
*/
explicit json_pointer(const std::string& s = "") : reference_tokens(split(s)) {}
/*!
@brief return a string representation of the JSON pointer
@invariant For each JSON pointer `ptr`, it holds:
@code {.cpp}
ptr == json_pointer(ptr.to_string());
@endcode
@return a string representation of the JSON pointer
@liveexample{The example shows the result of `to_string`.,
json_pointer__to_string}
@since version 2.0.0
*/
std::string to_string() const noexcept
{
return std::accumulate(reference_tokens.begin(), reference_tokens.end(),
std::string{},
[](const std::string & a, const std::string & b)
{
return a + "/" + escape(b);
});
}
/// @copydoc to_string()
operator std::string() const
{
return to_string();
}
/*!
@param[in] s reference token to be converted into an array index
@return integer representation of @a s
@throw out_of_range.404 if string @a s could not be converted to an integer
*/
static int array_index(const std::string& s)
{
std::size_t processed_chars = 0;
const int res = std::stoi(s, &processed_chars);
// check if the string was completely read
if (JSON_UNLIKELY(processed_chars != s.size()))
{
JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + s + "'"));
}
return res;
}
private:
/*!
@brief remove and return last reference pointer
@throw out_of_range.405 if JSON pointer has no parent
*/
std::string pop_back()
{
if (JSON_UNLIKELY(is_root()))
{
JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent"));
}
auto last = reference_tokens.back();
reference_tokens.pop_back();
return last;
}
/// return whether pointer points to the root document
bool is_root() const
{
return reference_tokens.empty();
}
json_pointer top() const
{
if (JSON_UNLIKELY(is_root()))
{
JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent"));
}
json_pointer result = *this;
result.reference_tokens = {reference_tokens[0]};
return result;
}
/*!
@brief create and return a reference to the pointed to value
@complexity Linear in the number of reference tokens.
@throw parse_error.109 if array index is not a number
@throw type_error.313 if value cannot be unflattened
*/
NLOHMANN_BASIC_JSON_TPL_DECLARATION
NLOHMANN_BASIC_JSON_TPL& get_and_create(NLOHMANN_BASIC_JSON_TPL& j) const;
/*!
@brief return a reference to the pointed to value
@note This version does not throw if a value is not present, but tries to
create nested values instead. For instance, calling this function
with pointer `"/this/that"` on a null value is equivalent to calling
`operator[]("this").operator[]("that")` on that value, effectively
changing the null value to an object.
@param[in] ptr a JSON value
@return reference to the JSON value pointed to by the JSON pointer
@complexity Linear in the length of 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.404 if the JSON pointer can not be resolved
*/
NLOHMANN_BASIC_JSON_TPL_DECLARATION
NLOHMANN_BASIC_JSON_TPL& get_unchecked(NLOHMANN_BASIC_JSON_TPL* ptr) const;
/*!
@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
*/
NLOHMANN_BASIC_JSON_TPL_DECLARATION
NLOHMANN_BASIC_JSON_TPL& get_checked(NLOHMANN_BASIC_JSON_TPL* ptr) const;
/*!
@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
*/
NLOHMANN_BASIC_JSON_TPL_DECLARATION
const NLOHMANN_BASIC_JSON_TPL& get_unchecked(const NLOHMANN_BASIC_JSON_TPL* ptr) const;
/*!
@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
*/
NLOHMANN_BASIC_JSON_TPL_DECLARATION
const NLOHMANN_BASIC_JSON_TPL& get_checked(const NLOHMANN_BASIC_JSON_TPL* ptr) const;
/*!
@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_UNLIKELY(reference_string[0] != '/'))
{
JSON_THROW(detail::parse_error::create(107, 1,
"JSON pointer must be empty or begin with '/' - was: '" +
reference_string + "'"));
}
// extract the reference tokens:
// - slash: position of the last read slash (or end of string)
// - start: position after the previous slash
for (
// search for the first slash after the first character
std::size_t slash = reference_string.find_first_of('/', 1),
// set the beginning of the first reference token
start = 1;
// we can stop if start == string::npos+1 = 0
start != 0;
// set the beginning of the next reference token
// (will eventually be 0 if slash == std::string::npos)
start = slash + 1,
// find next slash
slash = reference_string.find_first_of('/', start))
{
// use the text between the beginning of the reference token
// (start) and the last slash (slash).
auto reference_token = reference_string.substr(start, slash - start);
// check reference tokens are properly escaped
for (std::size_t pos = reference_token.find_first_of('~');
pos != std::string::npos;
pos = reference_token.find_first_of('~', pos + 1))
{
assert(reference_token[pos] == '~');
// ~ must be followed by 0 or 1
if (JSON_UNLIKELY(pos == reference_token.size() - 1 or
(reference_token[pos + 1] != '0' and
reference_token[pos + 1] != '1')))
{
JSON_THROW(detail::parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'"));
}
}
// 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`.
*/
NLOHMANN_BASIC_JSON_TPL_DECLARATION
static void flatten(const std::string& reference_string,
const NLOHMANN_BASIC_JSON_TPL& value,
NLOHMANN_BASIC_JSON_TPL& result);
/*!
@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
*/
NLOHMANN_BASIC_JSON_TPL_DECLARATION
static NLOHMANN_BASIC_JSON_TPL
unflatten(const NLOHMANN_BASIC_JSON_TPL& value);
friend bool operator==(json_pointer const& lhs,
json_pointer const& rhs) noexcept;
friend bool operator!=(json_pointer const& lhs,
json_pointer const& rhs) noexcept;
/// the reference tokens
std::vector<std::string> reference_tokens;
};
/*!
@brief a class to store JSON values
@ -486,7 +158,7 @@ class basic_json
{
private:
template<detail::value_t> friend struct detail::external_constructor;
friend ::nlohmann::json_pointer;
friend ::nlohmann::json_pointer<basic_json>;
friend ::nlohmann::detail::parser<basic_json>;
friend ::nlohmann::detail::serializer<basic_json>;
template<typename BasicJsonType>
@ -523,7 +195,7 @@ class basic_json
public:
using value_t = detail::value_t;
/// @copydoc nlohmann::json_pointer
using json_pointer = ::nlohmann::json_pointer;
using json_pointer = ::nlohmann::json_pointer<basic_json>;
template<typename T, typename SFINAE>
using json_serializer = JSONSerializer<T, SFINAE>;
/// helper type for initializer lists of basic_json values
@ -7789,400 +7461,6 @@ class basic_json
/// @}
};
//////////////////
// json_pointer //
//////////////////
NLOHMANN_BASIC_JSON_TPL_DECLARATION
NLOHMANN_BASIC_JSON_TPL&
json_pointer::get_and_create(NLOHMANN_BASIC_JSON_TPL& j) const
{
using size_type = typename NLOHMANN_BASIC_JSON_TPL::size_type;
auto result = &j;
// in case no reference tokens exist, return a reference to the JSON value
// j which will be overwritten by a primitive value
for (const auto& reference_token : reference_tokens)
{
switch (result->m_type)
{
case detail::value_t::null:
{
if (reference_token == "0")
{
// start a new array if reference token is 0
result = &result->operator[](0);
}
else
{
// start a new object otherwise
result = &result->operator[](reference_token);
}
break;
}
case detail::value_t::object:
{
// create an entry in the object
result = &result->operator[](reference_token);
break;
}
case detail::value_t::array:
{
// create an entry in the array
JSON_TRY
{
result = &result->operator[](static_cast<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;
}
/*
The following code is only reached if there exists a reference
token _and_ the current value is primitive. In this case, we have
an error situation, because primitive values may only occur as
single value; that is, with an empty list of reference tokens.
*/
default:
JSON_THROW(detail::type_error::create(313, "invalid value to unflatten"));
}
}
return *result;
}
NLOHMANN_BASIC_JSON_TPL_DECLARATION
NLOHMANN_BASIC_JSON_TPL&
json_pointer::get_unchecked(NLOHMANN_BASIC_JSON_TPL* ptr) const
{
using size_type = typename NLOHMANN_BASIC_JSON_TPL::size_type;
for (const auto& reference_token : reference_tokens)
{
// convert null values to arrays or objects before continuing
if (ptr->m_type == detail::value_t::null)
{
// check if reference token is a number
const bool nums =
std::all_of(reference_token.begin(), reference_token.end(),
[](const char x)
{
return (x >= '0' and x <= '9');
});
// change value to array for numbers or "-" or to object otherwise
*ptr = (nums or reference_token == "-")
? detail::value_t::array
: detail::value_t::object;
}
switch (ptr->m_type)
{
case detail::value_t::object:
{
// use unchecked object access
ptr = &ptr->operator[](reference_token);
break;
}
case detail::value_t::array:
{
// error condition (cf. RFC 6901, Sect. 4)
if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
{
JSON_THROW(detail::parse_error::create(106, 0,
"array index '" + reference_token +
"' must not begin with '0'"));
}
if (reference_token == "-")
{
// explicitly treat "-" as index beyond the end
ptr = &ptr->operator[](ptr->m_value.array->size());
}
else
{
// convert array index to number; unchecked access
JSON_TRY
{
ptr = &ptr->operator[](
static_cast<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;
}
NLOHMANN_BASIC_JSON_TPL_DECLARATION
NLOHMANN_BASIC_JSON_TPL&
json_pointer::get_checked(NLOHMANN_BASIC_JSON_TPL* ptr) const
{
using size_type = typename NLOHMANN_BASIC_JSON_TPL::size_type;
for (const auto& reference_token : reference_tokens)
{
switch (ptr->m_type)
{
case detail::value_t::object:
{
// note: at performs range check
ptr = &ptr->at(reference_token);
break;
}
case detail::value_t::array:
{
if (JSON_UNLIKELY(reference_token == "-"))
{
// "-" always fails the range check
JSON_THROW(detail::out_of_range::create(402,
"array index '-' (" + std::to_string(ptr->m_value.array->size()) +
") is out of range"));
}
// 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'"));
}
// 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;
}
NLOHMANN_BASIC_JSON_TPL_DECLARATION
const NLOHMANN_BASIC_JSON_TPL&
json_pointer::get_unchecked(const NLOHMANN_BASIC_JSON_TPL* ptr) const
{
using size_type = typename NLOHMANN_BASIC_JSON_TPL::size_type;
for (const auto& reference_token : reference_tokens)
{
switch (ptr->m_type)
{
case detail::value_t::object:
{
// use unchecked object access
ptr = &ptr->operator[](reference_token);
break;
}
case detail::value_t::array:
{
if (JSON_UNLIKELY(reference_token == "-"))
{
// "-" cannot be used for const access
JSON_THROW(detail::out_of_range::create(402,
"array index '-' (" + std::to_string(ptr->m_value.array->size()) +
") is out of range"));
}
// 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'"));
}
// 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;
}
NLOHMANN_BASIC_JSON_TPL_DECLARATION
const NLOHMANN_BASIC_JSON_TPL&
json_pointer::get_checked(const NLOHMANN_BASIC_JSON_TPL* ptr) const
{
using size_type = typename NLOHMANN_BASIC_JSON_TPL::size_type;
for (const auto& reference_token : reference_tokens)
{
switch (ptr->m_type)
{
case detail::value_t::object:
{
// note: at performs range check
ptr = &ptr->at(reference_token);
break;
}
case detail::value_t::array:
{
if (JSON_UNLIKELY(reference_token == "-"))
{
// "-" always fails the range check
JSON_THROW(detail::out_of_range::create(402,
"array index '-' (" + std::to_string(ptr->m_value.array->size()) +
") is out of range"));
}
// 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'"));
}
// 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;
}
NLOHMANN_BASIC_JSON_TPL_DECLARATION
void json_pointer::flatten(const std::string& reference_string,
const NLOHMANN_BASIC_JSON_TPL& value,
NLOHMANN_BASIC_JSON_TPL& result)
{
switch (value.m_type)
{
case detail::value_t::array:
{
if (value.m_value.array->empty())
{
// flatten empty array as null
result[reference_string] = nullptr;
}
else
{
// iterate array and use index as reference string
for (std::size_t i = 0; i < value.m_value.array->size(); ++i)
{
flatten(reference_string + "/" + std::to_string(i),
value.m_value.array->operator[](i), result);
}
}
break;
}
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;
}
}
}
NLOHMANN_BASIC_JSON_TPL_DECLARATION
NLOHMANN_BASIC_JSON_TPL
json_pointer::unflatten(const NLOHMANN_BASIC_JSON_TPL& value)
{
if (JSON_UNLIKELY(not value.is_object()))
{
JSON_THROW(detail::type_error::create(314, "only objects can be unflattened"));
}
NLOHMANN_BASIC_JSON_TPL result;
// iterate the JSON object values
for (const auto& element : *value.m_value.object)
{
if (JSON_UNLIKELY(not element.second.is_primitive()))
{
JSON_THROW(detail::type_error::create(315, "values in object must be primitive"));
}
// assign value to reference pointed to by JSON pointer; Note that if
// the JSON pointer is "" (i.e., points to the whole value), function
// get_and_create returns a reference to result itself. An assignment
// will then create a primitive value.
json_pointer(element.first).get_and_create(result) = element.second;
}
return result;
}
inline bool operator==(json_pointer const& lhs, json_pointer const& rhs) noexcept
{
return (lhs.reference_tokens == rhs.reference_tokens);
}
inline bool operator!=(json_pointer const& lhs, json_pointer const& rhs) noexcept
{
return not (lhs == rhs);
}
} // namespace nlohmann
///////////////////////

1
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@ -47,6 +47,7 @@ within a JSON document. It can be used with functions `at` and
@since version 2.0.0
*/
template<typename BasicJsonType>
class json_pointer;
/*!

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