toml11/toml/literal.hpp
2019-06-08 19:40:11 +09:00

92 lines
3.1 KiB
C++

// Copyright Toru Niina 2019.
// Distributed under the MIT License.
#ifndef TOML11_LITERAL_HPP
#define TOML11_LITERAL_HPP
#include "parser.hpp"
namespace toml
{
inline namespace literals
{
inline namespace toml_literals
{
inline ::toml::value operator"" _toml(const char* str, std::size_t len)
{
::toml::detail::location<std::vector<char>>
loc(/* filename = */ std::string("TOML literal encoded in a C++ code"),
/* contents = */ std::vector<char>(str, str + len));
// if there are some comments or empty lines, skip them.
using skip_line = ::toml::detail::repeat<toml::detail::sequence<
::toml::detail::maybe<::toml::detail::lex_ws>,
::toml::detail::maybe<::toml::detail::lex_comment>,
::toml::detail::lex_newline
>, ::toml::detail::at_least<1>>;
skip_line::invoke(loc);
// if there are some whitespaces before a value, skip them.
using skip_ws = ::toml::detail::repeat<
::toml::detail::lex_ws, ::toml::detail::at_least<1>>;
skip_ws::invoke(loc);
// to distinguish arrays and tables, first check it is a table or not.
//
// "[1,2,3]"_toml; // this is an array
// "[table]"_toml; // a table that has an empty table named "table" inside.
// "[[1,2,3]]"_toml; // this is an array of arrays
// "[[table]]"_toml; // this is a table that has an array of tables inside.
//
// "[[1]]"_toml; // this can be both... (currently it becomes a table)
// "1 = [{}]"_toml; // this is a table that has an array of table named 1.
// "[[1,]]"_toml; // this is an array of arrays.
// "[[1],]"_toml; // this also.
const auto the_front = loc.iter();
const bool is_table_key = ::toml::detail::lex_std_table::invoke(loc);
loc.reset(the_front);
const bool is_aots_key = ::toml::detail::lex_array_table::invoke(loc);
loc.reset(the_front);
// If it is neither a table-key or a array-of-table-key, it may be a value.
if(!is_table_key && !is_aots_key)
{
if(auto data = ::toml::detail::parse_value<::toml::value>(loc))
{
return data.unwrap();
}
}
// Note that still it can be a table, because the literal might be something
// like the following.
// ```cpp
// R"( // c++11 raw string literals
// key = "value"
// int = 42
// )"_toml;
// ```
// It is a valid toml file.
// It should be parsed as if we parse a file with this content.
if(auto data = ::toml::detail::parse_toml_file<::toml::value>(loc))
{
// TODO later I need to move this logic to parse_toml_file
// loc.reset(loc.begin()); // rollback to the top of the literal
// // skip needless characters for error message
// skip_line::invoke(loc); // skip the first several needless lines
// skip_ws::invoke(loc); // skip the first several needless whitespaces
return data.unwrap();
}
else // none of them.
{
throw ::toml::syntax_error(data.unwrap_err());
}
}
} // toml_literals
} // literals
} // toml
#endif//TOML11_LITERAL_HPP