tomlplusplus/include/toml++/toml_parse_error.h

//# This file is a part of toml++ and is subject to the the terms of the MIT license.
//# Copyright (c) 2019-2020 Mark Gillard <mark.gillard@outlook.com.au>
//# See https://github.com/marzer/tomlplusplus/blob/master/LICENSE for the full license text.
// SPDX-License-Identifier: MIT

#pragma once
//# {{
#include "toml_preprocessor.h"
#if !TOML_PARSER
	#error This header cannot not be included when TOML_PARSER is disabled.
#endif
//# }}
TOML_PUSH_WARNINGS
TOML_DISABLE_ALL_WARNINGS
#if TOML_EXCEPTIONS
	#include <stdexcept>
#endif
TOML_POP_WARNINGS

TOML_PUSH_WARNINGS
TOML_DISABLE_INIT_WARNINGS
TOML_DISABLE_MISC_WARNINGS

TOML_NAMESPACE_START
{
	TOML_ABI_NAMESPACE_BOOL(TOML_EXCEPTIONS, ex, noex)

	#if defined(DOXYGEN) || !TOML_EXCEPTIONS

	/// \brief	An error generated when parsing fails.
	/// 
	/// \remarks This class inherits from std::runtime_error when exceptions are enabled.
	/// 		 The public interface is the same regardless of exception mode.
	class parse_error final
	{
		private:
			std::string description_;
			source_region source_;

		public:

			TOML_NODISCARD_CTOR
			parse_error(std::string&& desc, source_region&& src) noexcept
				: description_{ std::move(desc) },
				source_{ std::move(src) }
			{}

			TOML_NODISCARD_CTOR
			parse_error(std::string&& desc, const source_region& src) noexcept
				: parse_error{ std::move(desc), source_region{ src } }
			{}

			TOML_NODISCARD_CTOR
				parse_error(std::string&& desc, const source_position& position, const source_path_ptr& path = {}) noexcept
				: parse_error{ std::move(desc), source_region{ position, position, path } }
			{}


			/// \brief	Returns a textual description of the error.
			/// \remark The backing string is guaranteed to be null-terminated.
			[[nodiscard]]
			std::string_view description() const noexcept
			{
				return description_;
			}

			/// \brief	Returns the region of the source document responsible for the error.
			[[nodiscard]]
			const source_region& source() const noexcept
			{
				return source_;
			}
	};

	#else

	class parse_error final
		: public std::runtime_error
	{
		private:
			source_region source_;

		public:

			TOML_NODISCARD_CTOR
			TOML_ATTR(nonnull)
			parse_error(const char* desc, source_region&& src) noexcept
				: std::runtime_error{ desc },
				source_{ std::move(src) }
			{}

			TOML_NODISCARD_CTOR
			TOML_ATTR(nonnull)
			parse_error(const char* desc, const source_region& src) noexcept
				: parse_error{ desc, source_region{ src } }
			{}

			TOML_NODISCARD_CTOR
			TOML_ATTR(nonnull)
			parse_error(const char* desc, const source_position& position, const source_path_ptr& path = {}) noexcept 
				: parse_error{ desc, source_region{ position, position, path } }
			{}

			[[nodiscard]]
			std::string_view description() const noexcept
			{
				return std::string_view{ what() };
			}

			[[nodiscard]]
			const source_region& source() const noexcept
			{
				return source_;
			}
	};

	#endif

	TOML_ABI_NAMESPACE_END // TOML_EXCEPTIONS

	/// \brief	Prints a parse_error to a stream.
	///
	/// \detail \cpp
	/// try
	/// {
	/// 	auto tbl = toml::parse("enabled = trUe"sv);
	/// }
	/// catch (const toml::parse_error & err)
	/// {
	/// 	std::cerr << "Parsing failed:\n"sv << err << std::endl;
	/// }
	/// \ecpp
	/// 
	/// \out
	/// Parsing failed:
	/// Encountered unexpected character while parsing boolean; expected 'true', saw 'trU'
	///		(error occurred at line 1, column 13)
	/// \eout
	/// 
	/// \tparam Char The output stream's underlying character type. Must be 1 byte in size.
	/// \param 	lhs	The stream.
	/// \param 	rhs	The parse_error.
	///
	/// \returns	The input stream.
	template <typename Char>
	inline std::basic_ostream<Char>& operator << (std::basic_ostream<Char>& lhs, const parse_error& rhs)
	{
		lhs << rhs.description();
		lhs << "\n\t(error occurred at "sv;
		lhs << rhs.source();
		lhs << ")"sv;
		return lhs;
	}

	#if !defined(DOXYGEN) && !TOML_HEADER_ONLY
		extern template TOML_API std::ostream& operator << (std::ostream&, const parse_error&);
	#endif
}
TOML_NAMESPACE_END

TOML_POP_WARNINGS