json/include/nlohmann/detail/exceptions.hpp
Niels Lohmann 29cd970b94
Consolidate documentation (#3071)
* 🔥 consolidate documentation
* ♻️ overwork std specializations
* 🚚 move images files to mkdocs
* ♻️ fix URLs
* 🔧 tweak MkDocs configuration
* 🔧 add namespaces
* 📝 document deprecations
* 📝 document documentation generation
* 🚸 improve search
* 🚸 add examples
* 🚧 start adding documentation for macros
* 📝 add note for https://github.com/nlohmann/json/issues/874#issuecomment-1001699139
* 📝 overwork example handling
* 📝 fix Markdown tables
2021-12-29 13:41:01 +01:00

237 lines
7.8 KiB
C++

#pragma once
#include <exception> // exception
#include <stdexcept> // runtime_error
#include <string> // to_string
#include <vector> // vector
#include <nlohmann/detail/value_t.hpp>
#include <nlohmann/detail/string_escape.hpp>
#include <nlohmann/detail/input/position_t.hpp>
#include <nlohmann/detail/macro_scope.hpp>
namespace nlohmann
{
namespace detail
{
////////////////
// exceptions //
////////////////
/// @brief general exception of the @ref basic_json class
/// @sa https://json.nlohmann.me/api/basic_json/exception/
class exception : public std::exception
{
public:
/// returns the explanatory string
const char* what() const noexcept override
{
return m.what();
}
/// the id of the exception
const int id; // NOLINT(cppcoreguidelines-non-private-member-variables-in-classes)
protected:
JSON_HEDLEY_NON_NULL(3)
exception(int id_, const char* what_arg) : id(id_), m(what_arg) {} // NOLINT(bugprone-throw-keyword-missing)
static std::string name(const std::string& ename, int id_)
{
return "[json.exception." + ename + "." + std::to_string(id_) + "] ";
}
template<typename BasicJsonType>
static std::string diagnostics(const BasicJsonType& leaf_element)
{
#if JSON_DIAGNOSTICS
std::vector<std::string> tokens;
for (const auto* current = &leaf_element; current->m_parent != nullptr; current = current->m_parent)
{
switch (current->m_parent->type())
{
case value_t::array:
{
for (std::size_t i = 0; i < current->m_parent->m_value.array->size(); ++i)
{
if (&current->m_parent->m_value.array->operator[](i) == current)
{
tokens.emplace_back(std::to_string(i));
break;
}
}
break;
}
case value_t::object:
{
for (const auto& element : *current->m_parent->m_value.object)
{
if (&element.second == current)
{
tokens.emplace_back(element.first.c_str());
break;
}
}
break;
}
case value_t::null: // LCOV_EXCL_LINE
case value_t::string: // LCOV_EXCL_LINE
case value_t::boolean: // LCOV_EXCL_LINE
case value_t::number_integer: // LCOV_EXCL_LINE
case value_t::number_unsigned: // LCOV_EXCL_LINE
case value_t::number_float: // LCOV_EXCL_LINE
case value_t::binary: // LCOV_EXCL_LINE
case value_t::discarded: // LCOV_EXCL_LINE
default: // LCOV_EXCL_LINE
break; // LCOV_EXCL_LINE
}
}
if (tokens.empty())
{
return "";
}
return "(" + std::accumulate(tokens.rbegin(), tokens.rend(), std::string{},
[](const std::string & a, const std::string & b)
{
return a + "/" + detail::escape(b);
}) + ") ";
#else
static_cast<void>(leaf_element);
return "";
#endif
}
private:
/// an exception object as storage for error messages
std::runtime_error m;
};
/// @brief exception indicating a parse error
/// @sa https://json.nlohmann.me/api/basic_json/parse_error/
class parse_error : public exception
{
public:
/*!
@brief create a parse error exception
@param[in] id_ the id of the exception
@param[in] pos the position where the error occurred (or with
chars_read_total=0 if the position cannot be
determined)
@param[in] what_arg the explanatory string
@return parse_error object
*/
template<typename BasicJsonType>
static parse_error create(int id_, const position_t& pos, const std::string& what_arg, const BasicJsonType& context)
{
std::string w = exception::name("parse_error", id_) + "parse error" +
position_string(pos) + ": " + exception::diagnostics(context) + what_arg;
return {id_, pos.chars_read_total, w.c_str()};
}
template<typename BasicJsonType>
static parse_error create(int id_, std::size_t byte_, const std::string& what_arg, const BasicJsonType& context)
{
std::string w = exception::name("parse_error", id_) + "parse error" +
(byte_ != 0 ? (" at byte " + std::to_string(byte_)) : "") +
": " + exception::diagnostics(context) + what_arg;
return {id_, byte_, w.c_str()};
}
/*!
@brief byte index of the parse error
The byte index of the last read character in the input file.
@note For an input with n bytes, 1 is the index of the first character and
n+1 is the index of the terminating null byte or the end of file.
This also holds true when reading a byte vector (CBOR or MessagePack).
*/
const std::size_t byte;
private:
parse_error(int id_, std::size_t byte_, const char* what_arg)
: exception(id_, what_arg), byte(byte_) {}
static std::string position_string(const position_t& pos)
{
return " at line " + std::to_string(pos.lines_read + 1) +
", column " + std::to_string(pos.chars_read_current_line);
}
};
/// @brief exception indicating errors with iterators
/// @sa https://json.nlohmann.me/api/basic_json/invalid_iterator/
class invalid_iterator : public exception
{
public:
template<typename BasicJsonType>
static invalid_iterator create(int id_, const std::string& what_arg, const BasicJsonType& context)
{
std::string w = exception::name("invalid_iterator", id_) + exception::diagnostics(context) + what_arg;
return {id_, w.c_str()};
}
private:
JSON_HEDLEY_NON_NULL(3)
invalid_iterator(int id_, const char* what_arg)
: exception(id_, what_arg) {}
};
/// @brief exception indicating executing a member function with a wrong type
/// @sa https://json.nlohmann.me/api/basic_json/type_error/
class type_error : public exception
{
public:
template<typename BasicJsonType>
static type_error create(int id_, const std::string& what_arg, const BasicJsonType& context)
{
std::string w = exception::name("type_error", id_) + exception::diagnostics(context) + what_arg;
return {id_, w.c_str()};
}
private:
JSON_HEDLEY_NON_NULL(3)
type_error(int id_, const char* what_arg) : exception(id_, what_arg) {}
};
/// @brief exception indicating access out of the defined range
/// @sa https://json.nlohmann.me/api/basic_json/out_of_range/
class out_of_range : public exception
{
public:
template<typename BasicJsonType>
static out_of_range create(int id_, const std::string& what_arg, const BasicJsonType& context)
{
std::string w = exception::name("out_of_range", id_) + exception::diagnostics(context) + what_arg;
return {id_, w.c_str()};
}
private:
JSON_HEDLEY_NON_NULL(3)
out_of_range(int id_, const char* what_arg) : exception(id_, what_arg) {}
};
/// @brief exception indicating other library errors
/// @sa https://json.nlohmann.me/api/basic_json/other_error/
class other_error : public exception
{
public:
template<typename BasicJsonType>
static other_error create(int id_, const std::string& what_arg, const BasicJsonType& context)
{
std::string w = exception::name("other_error", id_) + exception::diagnostics(context) + what_arg;
return {id_, w.c_str()};
}
private:
JSON_HEDLEY_NON_NULL(3)
other_error(int id_, const char* what_arg) : exception(id_, what_arg) {}
};
} // namespace detail
} // namespace nlohmann