///////////////////////////////////////////////////////////////////////////////
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// repeat_end_matcher.hpp
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//
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// Copyright 2008 Eric Niebler. Distributed under the Boost
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// Software License, Version 1.0. (See accompanying file
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// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_REPEAT_BEGIN_MATCHER_HPP_EAN_10_04_2005
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#define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_REPEAT_BEGIN_MATCHER_HPP_EAN_10_04_2005
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// MS compatible compilers support #pragma once
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#if defined(_MSC_VER)
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# pragma once
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#endif
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#include <boost/xpressive/detail/detail_fwd.hpp>
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#include <boost/xpressive/detail/core/quant_style.hpp>
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#include <boost/xpressive/detail/core/state.hpp>
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namespace boost { namespace xpressive { namespace detail
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{
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//
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// Note: here is the variable-width xpression quantifier. It always
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// matches at least once, so if the min is 0, it is the responsibility
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// of the parser to make it alternate with an epsilon matcher.
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//
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///////////////////////////////////////////////////////////////////////////////
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// repeat_begin_matcher
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//
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struct repeat_begin_matcher
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: quant_style<quant_variable_width, unknown_width::value, false>
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{
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int mark_number_;
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repeat_begin_matcher(int mark_number)
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: mark_number_(mark_number)
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{
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}
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template<typename BidiIter, typename Next>
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bool match(match_state<BidiIter> &state, Next const &next) const
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{
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sub_match_impl<BidiIter> &br = state.sub_match(this->mark_number_);
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unsigned int old_repeat_count = br.repeat_count_;
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bool old_zero_width = br.zero_width_;
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br.repeat_count_ = 1;
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br.zero_width_ = false;
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// "push" next onto the stack, so it can be "popped" in
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// repeat_end_matcher and used to loop back.
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if(next.BOOST_NESTED_TEMPLATE push_match<Next>(state))
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{
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return true;
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}
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br.repeat_count_ = old_repeat_count;
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br.zero_width_ = old_zero_width;
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return false;
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}
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};
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}}}
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#endif
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