/////////////////////////////////////////////////////////////////////////////// | |
// 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) && (_MSC_VER >= 1020) | |
# 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 |