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///////////////////////////////////////////////////////////////////////////////
// repeat_end_matcher.hpp
//
// Copyright 2008 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_REPEAT_BEGIN_MATCHER_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_REPEAT_BEGIN_MATCHER_HPP_EAN_10_04_2005
// MS compatible compilers support #pragma once
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/core/quant_style.hpp>
#include <boost/xpressive/detail/core/state.hpp>
namespace boost { namespace xpressive { namespace detail
{
//
// Note: here is the variable-width xpression quantifier. It always
// matches at least once, so if the min is 0, it is the responsibility
// of the parser to make it alternate with an epsilon matcher.
//
///////////////////////////////////////////////////////////////////////////////
// repeat_begin_matcher
//
struct repeat_begin_matcher
: quant_style<quant_variable_width, unknown_width::value, false>
{
int mark_number_;
repeat_begin_matcher(int mark_number)
: mark_number_(mark_number)
{
}
template<typename BidiIter, typename Next>
bool match(match_state<BidiIter> &state, Next const &next) const
{
sub_match_impl<BidiIter> &br = state.sub_match(this->mark_number_);
unsigned int old_repeat_count = br.repeat_count_;
bool old_zero_width = br.zero_width_;
br.repeat_count_ = 1;
br.zero_width_ = false;
// "push" next onto the stack, so it can be "popped" in
// repeat_end_matcher and used to loop back.
if(next.BOOST_NESTED_TEMPLATE push_match<Next>(state))
{
return true;
}
br.repeat_count_ = old_repeat_count;
br.zero_width_ = old_zero_width;
return false;
}
};
}}}
#endif