core/matcher/attr_matcher.hpp

0001 ///////////////////////////////////////////////////////////////////////////////
0002 // attr_matcher.hpp
0003 //
0004 //  Copyright 2008 Eric Niebler.
0005 //  Copyright 2008 David Jenkins.
0006 //
0007 //  Distributed under the Boost Software License, Version 1.0. (See
0008 //  accompanying file LICENSE_1_0.txt or copy at
0009 //  http://www.boost.org/LICENSE_1_0.txt)
0010
0011 #ifndef BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_ATTR_MATCHER_HPP_EAN_06_09_2007
0012 #define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_ATTR_MATCHER_HPP_EAN_06_09_2007
0013
0014 // MS compatible compilers support #pragma once
0015 #if defined(_MSC_VER)
0016 # pragma once
0017 #endif
0018
0019 #include <boost/xpressive/detail/detail_fwd.hpp>
0020 #include <boost/xpressive/detail/core/quant_style.hpp>
0021 #include <boost/xpressive/detail/core/state.hpp>
0022 #include <boost/xpressive/detail/utility/symbols.hpp>
0023
0024 namespace boost { namespace xpressive { namespace detail
0025 {
0026
0027     ///////////////////////////////////////////////////////////////////////////////
0028     // char_translate
0029     //
0030     template<typename Traits, bool ICase>
0031     struct char_translate
0032     {
0033         typedef typename Traits::char_type char_type;
0034         Traits const &traits_;
0035
0036         explicit char_translate(Traits const &tr)
0037           : traits_(tr)
0038         {}
0039
0040         char_type operator ()(char_type ch1) const
0041         {
0042             return this->traits_.translate(ch1);
0043         }
0044     private:
0045         char_translate &operator =(char_translate const &);
0046     };
0047
0048     ///////////////////////////////////////////////////////////////////////////////
0049     // char_translate
0050     //
0051     template<typename Traits>
0052     struct char_translate<Traits, true>
0053     {
0054         typedef typename Traits::char_type char_type;
0055         Traits const &traits_;
0056
0057         explicit char_translate(Traits const &tr)
0058           : traits_(tr)
0059         {}
0060
0061         char_type operator ()(char_type ch1) const
0062         {
0063             return this->traits_.translate_nocase(ch1);
0064         }
0065     private:
0066         char_translate &operator =(char_translate const &);
0067     };
0068
0069     ///////////////////////////////////////////////////////////////////////////////
0070     // attr_matcher
0071     //  Note: the Matcher is a std::map
0072     template<typename Matcher, typename Traits, typename ICase>
0073     struct attr_matcher
0074       : quant_style<quant_none, 0, false>
0075     {
0076         typedef typename Matcher::value_type::second_type const* result_type;
0077
0078         attr_matcher(int slot, Matcher const &matcher, Traits const& tr)
0079           : slot_(slot-1)
0080         {
0081             char_translate<Traits, ICase::value> trans(tr);
0082             this->sym_.load(matcher, trans);
0083         }
0084
0085         template<typename BidiIter, typename Next>
0086         bool match(match_state<BidiIter> &state, Next const &next) const
0087         {
0088             BidiIter tmp = state.cur_;
0089             char_translate<Traits, ICase::value> trans(traits_cast<Traits>(state));
0090             result_type const &result = this->sym_(state.cur_, state.end_, trans);
0091             if(result)
0092             {
0093                 void const *old_slot = state.attr_context_.attr_slots_[this->slot_];
0094                 state.attr_context_.attr_slots_[this->slot_] = &*result;
0095                 if(next.match(state))
0096                 {
0097                     return true;
0098                 }
0099                 state.attr_context_.attr_slots_[this->slot_] = old_slot;
0100             }
0101             state.cur_ = tmp;
0102             return false;
0103         }
0104
0105         int slot_;
0106         boost::xpressive::detail::symbols<Matcher> sym_;
0107     };
0108
0109 }}}
0110
0111 #endif