mapnik/src/expression.cpp

/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2011 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
 *
 *****************************************************************************/

// mapnik
#include <mapnik/expression.hpp>
#include <mapnik/config_error.hpp>
#include <mapnik/unicode.hpp>
#include <mapnik/expression_grammar.hpp>

// boost
#include <boost/algorithm/string.hpp>
#include <boost/make_shared.hpp>

namespace mapnik
{

expression_ptr expression_factory::compile(std::string const& str,transcoder const& tr)
{
    expression_ptr expr(boost::make_shared<expr_node>(true));
    std::string::const_iterator itr = str.begin();
    std::string::const_iterator end = str.end();
    mapnik::expression_grammar<std::string::const_iterator> g(tr);
    bool r = boost::spirit::qi::phrase_parse(itr,end,g, boost::spirit::standard_wide::space,*expr);
    if (r && itr==end)
    {
        return expr;
    }
    else
    {
        throw config_error( "Failed to parse expression: \"" + str + "\"" );
    }
}

bool expression_factory::parse_from_string(expression_ptr const& expr,
                                           std::string const& str,
                                           mapnik::expression_grammar<std::string::const_iterator> const& g)
{
    std::string::const_iterator itr = str.begin();
    std::string::const_iterator end = str.end();
    bool r = boost::spirit::qi::phrase_parse(itr,end,g, boost::spirit::standard_wide::space,*expr);
    return (r && itr==end);
}

expression_ptr parse_expression (std::string const& wkt,std::string const& encoding)
{
    transcoder tr(encoding);
    return expression_factory::compile(wkt,tr);
}

expression_ptr parse_expression (std::string const& wkt)
{
    return parse_expression(wkt,"utf8");
}
}