boost/xpressive/detail/static/visitor.hpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // visitor.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_STATIC_VISITOR_HPP_EAN_10_04_2005
   9 #define BOOST_XPRESSIVE_DETAIL_STATIC_VISITOR_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/ref.hpp>
  17 #include <boost/shared_ptr.hpp>
  18 #include <boost/xpressive/detail/detail_fwd.hpp>
  19 #include <boost/xpressive/detail/core/regex_impl.hpp>
  20 #include <boost/xpressive/detail/static/transmogrify.hpp>
  21 #include <boost/xpressive/detail/core/matcher/mark_begin_matcher.hpp>
  22
  23 namespace boost { namespace xpressive { namespace detail
  24 {
  25     ///////////////////////////////////////////////////////////////////////////////
  26     //
  27     template<typename BidiIter>
  28     struct xpression_visitor_base
  29     {
  30         explicit xpression_visitor_base(shared_ptr<regex_impl<BidiIter> > const &self)
  31           : self_(self)
  32         {
  33         }
  34
  35         void swap(xpression_visitor_base<BidiIter> &that)
  36         {
  37             this->self_.swap(that.self_);
  38         }
  39
  40         int get_hidden_mark()
  41         {
  42             return -(int)(++this->self_->hidden_mark_count_);
  43         }
  44
  45         void mark_number(int mark_nbr)
  46         {
  47             if(0 < mark_nbr)
  48             {
  49                 this->self_->mark_count_ =
  50                     (std::max)(this->self_->mark_count_, (std::size_t)mark_nbr);
  51             }
  52         }
  53
  54         shared_ptr<regex_impl<BidiIter> > &self()
  55         {
  56             return this->self_;
  57         }
  58
  59     protected:
  60
  61         template<typename Matcher>
  62         void visit_(Matcher const &)
  63         {
  64         }
  65
  66         void visit_(reference_wrapper<basic_regex<BidiIter> > const &rex)
  67         {
  68             // when visiting an embedded regex, track the references
  69             this->self_->track_reference(*detail::core_access<BidiIter>::get_regex_impl(rex.get()));
  70         }
  71
  72         void visit_(reference_wrapper<basic_regex<BidiIter> const> const &rex)
  73         {
  74             // when visiting an embedded regex, track the references
  75             this->self_->track_reference(*detail::core_access<BidiIter>::get_regex_impl(rex.get()));
  76         }
  77
  78         void visit_(tracking_ptr<regex_impl<BidiIter> > const &rex)
  79         {
  80             // when visiting an embedded regex, track the references
  81             this->self_->track_reference(*rex.get());
  82         }
  83
  84         void visit_(mark_placeholder const &backref)
  85         {
  86             // keep track of the largest mark number found
  87             this->mark_number(backref.mark_number_);
  88         }
  89
  90         void visit_(mark_begin_matcher const &mark_begin)
  91         {
  92             // keep track of the largest mark number found
  93             this->mark_number(mark_begin.mark_number_);
  94         }
  95
  96     private:
  97         shared_ptr<regex_impl<BidiIter> > self_;
  98     };
  99
 100     ///////////////////////////////////////////////////////////////////////////////
 101     //
 102     template<typename BidiIter, typename ICase, typename Traits>
 103     struct xpression_visitor
 104       : xpression_visitor_base<BidiIter>
 105     {
 106         typedef BidiIter iterator_type;
 107         typedef ICase icase_type;
 108         typedef Traits traits_type;
 109         typedef typename boost::iterator_value<BidiIter>::type char_type;
 110
 111         explicit xpression_visitor(Traits const &tr, shared_ptr<regex_impl<BidiIter> > const &self)
 112           : xpression_visitor_base<BidiIter>(self)
 113           , traits_(tr)
 114         {
 115         }
 116
 117         template<typename Matcher>
 118         struct apply
 119         {
 120             typedef typename transmogrify<BidiIter, ICase, Traits, Matcher>::type type;
 121         };
 122
 123         template<typename Matcher>
 124         typename apply<Matcher>::type
 125         call(Matcher const &matcher)
 126         {
 127             this->visit_(matcher);
 128             return transmogrify<BidiIter, ICase, Traits, Matcher>::call(matcher, *this);
 129         }
 130
 131         Traits const &traits() const
 132         {
 133             return this->traits_;
 134         }
 135
 136     private:
 137
 138         Traits traits_;
 139     };
 140
 141 }}}
 142
 143 #endif