mapnik/include/mapnik/util/sort_by.hpp

59 lines
1.9 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2025 Artem Pavlenko
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
#ifndef MAPNIK_SORT_BY_HPP
#define MAPNIK_SORT_BY_HPP
#include <boost/spirit/home/x3.hpp>
#include <boost/fusion/include/std_pair.hpp>
namespace mapnik {
using sort_by_type = std::pair<std::string, bool>;
inline bool parse_sort_by(std::string const& str, sort_by_type & result)
{
namespace x3 = boost::spirit::x3;
auto itr = str.begin();
auto end = str.end();
auto apply_sort_by = [&](auto const& ctx) {
result.first = _attr(ctx);
};
auto apply_desc = [&](auto const& ctx) {
result.second = true;
};
if (!x3::phrase_parse(itr, end,
x3::no_skip[(+x3::char_("a-zA-Z_0-9-"))][apply_sort_by]
> -(x3::no_case[x3::lit("DESC")][apply_desc] | x3::no_case[x3::lit("ASC")]),
// ASC is a default
x3::space
) || (itr != end))
{
return false;
}
return true;
}
} // namespace mapnik
#endif // MAPNIK_SORT_BY_HPP