#ifndef BOOST_METAPARSE_V1_FOLDL_HPP #define BOOST_METAPARSE_V1_FOLDL_HPP // Copyright Abel Sinkovics (abel@sinkovics.hu) 2011. // 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/accept.hpp> #include <boost/metaparse/v1/is_error.hpp> #include <boost/metaparse/v1/get_position.hpp> #include <boost/metaparse/v1/get_result.hpp> #include <boost/metaparse/v1/get_remaining.hpp> #include <boost/mpl/eval_if.hpp> namespace boost { namespace metaparse { namespace v1 { template <class P, class State, class ForwardOp> struct foldl { private: template <class Res> struct apply_unchecked : // foldl never returns error // I need to use apply_wrap, and not apply, because apply would // build a metafunction class from foldl<P, State, ForwardOp> // when ForwardOp is a lambda expression. foldl< P, typename ForwardOp::template apply< typename State::type, typename get_result<Res>::type >, ForwardOp >::template apply< typename get_remaining<Res>::type, typename get_position<Res>::type > {}; template <class S, class Pos> struct next_iteration : accept<typename State::type, S, Pos> {}; public: typedef foldl type; template <class S, class Pos> struct apply : boost::mpl::eval_if< typename is_error<typename P::template apply<S, Pos> >::type, next_iteration<S, Pos>, apply_unchecked<typename P::template apply<S, Pos> > > {}; }; } } } #endif