end_matcher.hpp

来自「support vector clustering for vc++」· HPP 代码 · 共 67 行

///////////////////////////////////////////////////////////////////////////////
// end_matcher.hpp
//
//  Copyright 2004 Eric Niebler. 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)

#ifndef BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_END_MATCHER_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_END_MATCHER_HPP_EAN_10_04_2005

// MS compatible compilers support #pragma once
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif

#include <boost/assert.hpp>
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/core/quant_style.hpp>
#include <boost/xpressive/detail/core/state.hpp>
#include <boost/xpressive/detail/core/sub_match_impl.hpp>
#include <boost/xpressive/detail/core/flow_control.hpp>

namespace boost { namespace xpressive { namespace detail
{

    ///////////////////////////////////////////////////////////////////////////////
    // end_matcher
    //
    struct end_matcher
      : quant_style_assertion
    {
        template<typename BidiIter, typename Next>
        static bool match(state_type<BidiIter> &state, Next const &)
        {
            BidiIter const tmp = state.cur_;
            sub_match_impl<BidiIter> &s0 = state.sub_match(0);
            BOOST_ASSERT(!s0.matched);

            // SPECIAL: if there is a match context on the context stack, then
            // this pattern has been nested within another. pop that context and
            // continue executing.
            if(state.context_.prev_context_)
            {
                if(!pop_context_match(state))
                {
                    return false;
                }
            }
            else if(state.flags_.match_all_ && !state.eos() ||
                    state.flags_.match_not_null_ && state.cur_ == s0.begin_)
            {
                return false;
            }

            // record the end of sub-match zero
            s0.first = s0.begin_;
            s0.second = tmp;
            s0.matched = true;

            return true;
        }
    };

}}}

#endif