#ifndef BOOST_METAPARSE_V1_KEYWORD_HPP #define BOOST_METAPARSE_V1_KEYWORD_HPP // Copyright Abel Sinkovics (abel@sinkovics.hu) 2009 - 2010. // Distributed under the Boost Software License, Version 1.0. // (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #include <boost/metaparse/v1/impl/void_.hpp> #include <boost/metaparse/v1/lit.hpp> #include <boost/metaparse/v1/return_.hpp> #include <boost/metaparse/v1/is_error.hpp> #include <boost/metaparse/v1/get_remaining.hpp> #include <boost/metaparse/v1/get_position.hpp> #include <boost/mpl/if.hpp> #include <boost/mpl/eval_if.hpp> #include <boost/mpl/empty.hpp> #include <boost/mpl/pop_front.hpp> #include <boost/mpl/front.hpp> namespace boost { namespace metaparse { namespace v1 { // Does not consume/check anything after the keyword template <class Kw, class ResultType = impl::void_> struct keyword { private: struct nonempty { private: typedef lit<typename boost::mpl::front<Kw>::type> next_char_parser; typedef keyword<typename boost::mpl::pop_front<Kw>::type, ResultType> rest_parser; template <class S, class Pos> struct apply_unchecked : rest_parser::template apply< typename get_remaining< typename next_char_parser::template apply<S, Pos> >::type, typename get_position< typename next_char_parser::template apply<S, Pos> >::type > {}; public: template <class S, class Pos> struct apply : boost::mpl::eval_if< typename is_error< typename next_char_parser::template apply<S, Pos> >::type, typename next_char_parser::template apply<S, Pos>, apply_unchecked<S, Pos> > {}; }; public: typedef keyword type; template <class S, class Pos> struct apply : boost::mpl::if_< boost::mpl::empty<Kw>, return_<ResultType>, nonempty >::type::template apply<S, Pos> {}; }; } } } #endif