ceph/src/boost/libs/xpressive/include/boost/xpressive/detail/core/matcher/repeat_begin_matcher.hpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // repeat_end_matcher.hpp
   3 //
   4 //  Copyright 2008 Eric Niebler. Distributed under the Boost
   5 //  Software License, Version 1.0. (See accompanying file
   6 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7
   8 #ifndef BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_REPEAT_BEGIN_MATCHER_HPP_EAN_10_04_2005
   9 #define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_REPEAT_BEGIN_MATCHER_HPP_EAN_10_04_2005
  10
  11 // MS compatible compilers support #pragma once
  12 #if defined(_MSC_VER)
  13 # pragma once
  14 #endif
  15
  16 #include <boost/xpressive/detail/detail_fwd.hpp>
  17 #include <boost/xpressive/detail/core/quant_style.hpp>
  18 #include <boost/xpressive/detail/core/state.hpp>
  19
  20 namespace boost { namespace xpressive { namespace detail
  21 {
  22
  23     //
  24     // Note: here is the variable-width xpression quantifier. It always
  25     // matches at least once, so if the min is 0, it is the responsibility
  26     // of the parser to make it alternate with an epsilon matcher.
  27     //
  28
  29     ///////////////////////////////////////////////////////////////////////////////
  30     // repeat_begin_matcher
  31     //
  32     struct repeat_begin_matcher
  33       : quant_style<quant_variable_width, unknown_width::value, false>
  34     {
  35         int mark_number_;
  36
  37         repeat_begin_matcher(int mark_number)
  38           : mark_number_(mark_number)
  39         {
  40         }
  41
  42         template<typename BidiIter, typename Next>
  43         bool match(match_state<BidiIter> &state, Next const &next) const
  44         {
  45             sub_match_impl<BidiIter> &br = state.sub_match(this->mark_number_);
  46
  47             unsigned int old_repeat_count = br.repeat_count_;
  48             bool old_zero_width = br.zero_width_;
  49
  50             br.repeat_count_ = 1;
  51             br.zero_width_ = false;
  52
  53             // "push" next onto the stack, so it can be "popped" in
  54             // repeat_end_matcher and used to loop back.
  55             if(next.BOOST_NESTED_TEMPLATE push_match<Next>(state))
  56             {
  57                 return true;
  58             }
  59
  60             br.repeat_count_ = old_repeat_count;
  61             br.zero_width_ = old_zero_width;
  62
  63             return false;
  64         }
  65     };
  66
  67 }}}
  68
  69 #endif