core/matcher/mark_matcher.hpp

0001 ///////////////////////////////////////////////////////////////////////////////
0002 // mark_matcher.hpp
0003 //
0004 //  Copyright 2008 Eric Niebler. Distributed under the Boost
0005 //  Software License, Version 1.0. (See accompanying file
0006 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007
0008 #ifndef BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_MARK_MATCHER_HPP_EAN_10_04_2005
0009 #define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_MARK_MATCHER_HPP_EAN_10_04_2005
0010
0011 // MS compatible compilers support #pragma once
0012 #if defined(_MSC_VER)
0013 # pragma once
0014 #endif
0015
0016 #include <boost/assert.hpp>
0017 #include <boost/xpressive/detail/detail_fwd.hpp>
0018 #include <boost/xpressive/detail/core/quant_style.hpp>
0019 #include <boost/xpressive/detail/core/state.hpp>
0020 #include <boost/xpressive/detail/utility/traits_utils.hpp>
0021
0022 namespace boost { namespace xpressive { namespace detail
0023 {
0024
0025     // TODO: the mark matcher is acually a fixed-width matcher, but the width is
0026     // not known until pattern match time.
0027
0028     ///////////////////////////////////////////////////////////////////////////////
0029     // mark_matcher
0030     //
0031     template<typename Traits, typename ICase>
0032     struct mark_matcher
0033       : quant_style_variable_width
0034     {
0035         typedef ICase icase_type;
0036         int mark_number_;
0037
0038         mark_matcher(int mark_number, Traits const &)
0039           : mark_number_(mark_number)
0040         {
0041         }
0042
0043         template<typename BidiIter, typename Next>
0044         bool match(match_state<BidiIter> &state, Next const &next) const
0045         {
0046             BOOST_ASSERT(this->mark_number_ < static_cast<int>(state.mark_count_));
0047             sub_match_impl<BidiIter> const &br = state.sub_match(this->mark_number_);
0048
0049             if(!br.matched)
0050             {
0051                 return false;
0052             }
0053
0054             BidiIter const tmp = state.cur_;
0055             for(BidiIter begin = br.first, end = br.second; begin != end; ++begin, ++state.cur_)
0056             {
0057                 if(state.eos()
0058                     || detail::translate(*state.cur_, traits_cast<Traits>(state), icase_type())
0059                     != detail::translate(*begin, traits_cast<Traits>(state), icase_type()))
0060                 {
0061                     state.cur_ = tmp;
0062                     return false;
0063                 }
0064             }
0065
0066             if(next.match(state))
0067             {
0068                 return true;
0069             }
0070
0071             state.cur_ = tmp;
0072             return false;
0073         }
0074     };
0075
0076 }}}
0077
0078 #endif