detail/static/visitor.hpp

0001 ///////////////////////////////////////////////////////////////////////////////
0002 // visitor.hpp
0003 //
0004 //  Copyright 2008 Eric Niebler. Distributed under the Boost
0005 //  Software License, Version 1.0. (See accompanying file
0006 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007
0008 #ifndef BOOST_XPRESSIVE_DETAIL_STATIC_VISITOR_HPP_EAN_10_04_2005
0009 #define BOOST_XPRESSIVE_DETAIL_STATIC_VISITOR_HPP_EAN_10_04_2005
0010
0011 // MS compatible compilers support #pragma once
0012 #if defined(_MSC_VER)
0013 # pragma once
0014 #endif
0015
0016 #include <boost/ref.hpp>
0017 #include <boost/shared_ptr.hpp>
0018 #include <boost/xpressive/detail/detail_fwd.hpp>
0019 #include <boost/xpressive/detail/core/regex_impl.hpp>
0020 #include <boost/xpressive/detail/static/transmogrify.hpp>
0021 #include <boost/xpressive/detail/core/matcher/mark_begin_matcher.hpp>
0022
0023 namespace boost { namespace xpressive { namespace detail
0024 {
0025     ///////////////////////////////////////////////////////////////////////////////
0026     //
0027     template<typename BidiIter>
0028     struct xpression_visitor_base
0029     {
0030         explicit xpression_visitor_base(shared_ptr<regex_impl<BidiIter> > const &self)
0031           : self_(self)
0032         {
0033         }
0034
0035         void swap(xpression_visitor_base<BidiIter> &that)
0036         {
0037             this->self_.swap(that.self_);
0038         }
0039
0040         int get_hidden_mark()
0041         {
0042             return -(int)(++this->self_->hidden_mark_count_);
0043         }
0044
0045         void mark_number(int mark_nbr)
0046         {
0047             if(0 < mark_nbr)
0048             {
0049                 this->self_->mark_count_ =
0050                     (std::max)(this->self_->mark_count_, (std::size_t)mark_nbr);
0051             }
0052         }
0053
0054         shared_ptr<regex_impl<BidiIter> > &self()
0055         {
0056             return this->self_;
0057         }
0058
0059     protected:
0060
0061         template<typename Matcher>
0062         void visit_(Matcher const &)
0063         {
0064         }
0065
0066         void visit_(reference_wrapper<basic_regex<BidiIter> > const &rex)
0067         {
0068             // when visiting an embedded regex, track the references
0069             this->self_->track_reference(*detail::core_access<BidiIter>::get_regex_impl(rex.get()));
0070         }
0071
0072         void visit_(reference_wrapper<basic_regex<BidiIter> const> const &rex)
0073         {
0074             // when visiting an embedded regex, track the references
0075             this->self_->track_reference(*detail::core_access<BidiIter>::get_regex_impl(rex.get()));
0076         }
0077
0078         void visit_(tracking_ptr<regex_impl<BidiIter> > const &rex)
0079         {
0080             // when visiting an embedded regex, track the references
0081             this->self_->track_reference(*rex.get());
0082         }
0083
0084         void visit_(mark_placeholder const &backref)
0085         {
0086             // keep track of the largest mark number found
0087             this->mark_number(backref.mark_number_);
0088         }
0089
0090         void visit_(mark_begin_matcher const &mark_begin)
0091         {
0092             // keep track of the largest mark number found
0093             this->mark_number(mark_begin.mark_number_);
0094         }
0095
0096     private:
0097         shared_ptr<regex_impl<BidiIter> > self_;
0098     };
0099
0100     ///////////////////////////////////////////////////////////////////////////////
0101     //
0102     template<typename BidiIter, typename ICase, typename Traits>
0103     struct xpression_visitor
0104       : xpression_visitor_base<BidiIter>
0105     {
0106         typedef BidiIter iterator_type;
0107         typedef ICase icase_type;
0108         typedef Traits traits_type;
0109         typedef typename boost::iterator_value<BidiIter>::type char_type;
0110
0111         explicit xpression_visitor(Traits const &tr, shared_ptr<regex_impl<BidiIter> > const &self)
0112           : xpression_visitor_base<BidiIter>(self)
0113           , traits_(tr)
0114         {
0115         }
0116
0117         template<typename Matcher>
0118         struct apply
0119         {
0120             typedef typename transmogrify<BidiIter, ICase, Traits, Matcher>::type type;
0121         };
0122
0123         template<typename Matcher>
0124         typename apply<Matcher>::type
0125         call(Matcher const &matcher)
0126         {
0127             this->visit_(matcher);
0128             return transmogrify<BidiIter, ICase, Traits, Matcher>::call(matcher, *this);
0129         }
0130
0131         Traits const &traits() const
0132         {
0133             return this->traits_;
0134         }
0135
0136     private:
0137
0138         Traits traits_;
0139     };
0140
0141 }}}
0142
0143 #endif