ceph/src/boost/libs/xpressive/include/boost/xpressive/detail/core/flow_control.hpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // flow_control.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_FLOW_CONTROL_HPP_EAN_10_04_2005
   9 #define BOOST_XPRESSIVE_DETAIL_CORE_FLOW_CONTROL_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/regex_impl.hpp>
  18 #include <boost/xpressive/detail/core/state.hpp>
  19 #include <boost/xpressive/detail/utility/ignore_unused.hpp>
  20
  21 namespace boost { namespace xpressive { namespace detail
  22 {
  23
  24 ///////////////////////////////////////////////////////////////////////////////
  25 // push_context_match
  26 //
  27 template<typename BidiIter>
  28 inline bool push_context_match
  29 (
  30     regex_impl<BidiIter> const &impl
  31   , match_state<BidiIter> &state
  32   , matchable<BidiIter> const &next
  33 )
  34 {
  35     // avoid infinite recursion
  36     // BUGBUG this only catches direct infinite recursion, like sregex::compile("(?R)"), but
  37     // not indirect infinite recursion where two rules invoke each other recursively.
  38     if(state.is_active_regex(impl) && state.cur_ == state.sub_match(0).begin_)
  39     {
  40         return next.match(state);
  41     }
  42
  43     // save state
  44     match_context<BidiIter> context = state.push_context(impl, next, context);
  45     detail::ignore_unused(context);
  46
  47     // match the nested regex and uninitialize the match context
  48     // (reclaims the sub_match objects if necessary)
  49     return state.pop_context(impl, impl.xpr_->match(state));
  50 }
  51
  52 ///////////////////////////////////////////////////////////////////////////////
  53 // pop_context_match
  54 //
  55 template<typename BidiIter>
  56 inline bool pop_context_match(match_state<BidiIter> &state)
  57 {
  58     // save state
  59     // BUGBUG nested regex could have changed state.traits_
  60     match_context<BidiIter> &context(*state.context_.prev_context_);
  61     state.swap_context(context);
  62
  63     // Finished matching the nested regex; now match the rest of the enclosing regex
  64     bool success = context.next_ptr_->match(state);
  65
  66     // restore state
  67     state.swap_context(context);
  68     return success;
  69 }
  70
  71 }}} // namespace boost::xpressive::detail
  72
  73 #endif
  74