williamr@2: //=======================================================================
williamr@2: // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
williamr@2: // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
williamr@2: //
williamr@2: // Distributed under the Boost Software License, Version 1.0. (See
williamr@2: // accompanying file LICENSE_1_0.txt or copy at
williamr@2: // http://www.boost.org/LICENSE_1_0.txt)
williamr@2: //=======================================================================
williamr@2: //
williamr@2: // Revision History:
williamr@2: //   01 April 2001: Modified to use new <boost/limits.hpp> header. (JMaddock)
williamr@2: //
williamr@2: #ifndef BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP
williamr@2: #define BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP
williamr@2: 
williamr@2: #include <iosfwd>
williamr@2: #include <boost/config.hpp>
williamr@2: #include <boost/property_map.hpp>
williamr@2: #include <boost/graph/graph_traits.hpp>
williamr@2: #include <boost/limits.hpp>
williamr@2: #include <boost/graph/detail/is_same.hpp>
williamr@2: 
williamr@2: namespace boost {
williamr@2: 
williamr@2:   // This is a bit more convenient than std::numeric_limits because
williamr@2:   // you don't have to explicitly provide type T.
williamr@2:   template <class T>
williamr@2:   inline T numeric_limits_max(T) { return (std::numeric_limits<T>::max)(); }
williamr@2: 
williamr@2:   //========================================================================
williamr@2:   // Event Tags
williamr@2: 
williamr@2:   namespace detail {
williamr@2:     // For partial specialization workaround
williamr@2:     enum event_visitor_enum
williamr@2:     { on_no_event_num,
williamr@2:       on_initialize_vertex_num, on_start_vertex_num,
williamr@2:       on_discover_vertex_num, on_finish_vertex_num, on_examine_vertex_num,
williamr@2:       on_examine_edge_num, on_tree_edge_num, on_non_tree_edge_num,
williamr@2:       on_gray_target_num, on_black_target_num,
williamr@2:       on_forward_or_cross_edge_num, on_back_edge_num,
williamr@2:       on_edge_relaxed_num, on_edge_not_relaxed_num,
williamr@2:       on_edge_minimized_num, on_edge_not_minimized_num
williamr@2:     };
williamr@2: 
williamr@2:     template<typename Event, typename Visitor>
williamr@2:     struct functor_to_visitor : Visitor
williamr@2:     {
williamr@2:       typedef Event event_filter;
williamr@2:       functor_to_visitor(const Visitor& visitor) : Visitor(visitor) {}
williamr@2:     };
williamr@2: 
williamr@2:   } // namespace detail
williamr@2: 
williamr@2:   struct on_no_event { enum { num = detail::on_no_event_num }; };
williamr@2: 
williamr@2:   struct on_initialize_vertex {
williamr@2:     enum { num = detail::on_initialize_vertex_num }; };
williamr@2:   struct on_start_vertex { enum { num = detail::on_start_vertex_num }; };
williamr@2:   struct on_discover_vertex { enum { num = detail::on_discover_vertex_num }; };
williamr@2:   struct on_examine_vertex { enum { num = detail::on_examine_vertex_num }; };
williamr@2:   struct on_finish_vertex { enum { num = detail::on_finish_vertex_num }; };
williamr@2: 
williamr@2:   struct on_examine_edge { enum { num = detail::on_examine_edge_num }; };
williamr@2:   struct on_tree_edge { enum { num = detail::on_tree_edge_num }; };
williamr@2:   struct on_non_tree_edge { enum { num = detail::on_non_tree_edge_num }; };
williamr@2:   struct on_gray_target { enum { num = detail::on_gray_target_num }; };
williamr@2:   struct on_black_target { enum { num = detail::on_black_target_num }; };
williamr@2:   struct on_forward_or_cross_edge {
williamr@2:     enum { num = detail::on_forward_or_cross_edge_num }; };
williamr@2:   struct on_back_edge { enum { num = detail::on_back_edge_num }; };
williamr@2: 
williamr@2:   struct on_edge_relaxed { enum { num = detail::on_edge_relaxed_num }; };
williamr@2:   struct on_edge_not_relaxed {
williamr@2:     enum { num = detail::on_edge_not_relaxed_num }; };
williamr@2:   struct on_edge_minimized { enum { num = detail::on_edge_minimized_num }; };
williamr@2:   struct on_edge_not_minimized {
williamr@2:     enum { num = detail::on_edge_not_minimized_num }; };
williamr@2: 
williamr@2:   struct true_tag { enum { num = true }; };
williamr@2:   struct false_tag { enum { num = false }; };
williamr@2: 
williamr@2:   //========================================================================
williamr@2:   // base_visitor and null_visitor
williamr@2: 
williamr@2:   // needed for MSVC workaround
williamr@2:   template <class Visitor>
williamr@2:   struct base_visitor {
williamr@2:     typedef on_no_event event_filter;
williamr@2:     template <class T, class Graph>
williamr@2:     void operator()(T, Graph&) { }
williamr@2:   };
williamr@2: 
williamr@2:   struct null_visitor : public base_visitor<null_visitor> {
williamr@2:     typedef on_no_event event_filter;
williamr@2:     template <class T, class Graph>
williamr@2:     void operator()(T, Graph&) { }
williamr@2:   };
williamr@2: 
williamr@2:   //========================================================================
williamr@2:   // The invoke_visitors() function
williamr@2: 
williamr@2:   namespace detail {
williamr@2:     template <class Visitor, class T, class Graph>
williamr@2:     inline void
williamr@2:     invoke_dispatch(Visitor& v, T x, Graph& g, true_tag) {
williamr@2:        v(x, g);
williamr@2:     }
williamr@2:     template <class Visitor, class T, class Graph>
williamr@2:     inline void
williamr@2:     invoke_dispatch(Visitor&, T, Graph&, false_tag) { }
williamr@2:   } // namespace detail
williamr@2: 
williamr@2:   template <class Visitor, class Rest, class T, class Graph, class Tag>
williamr@2:   inline void
williamr@2:   invoke_visitors(std::pair<Visitor, Rest>& vlist, T x, Graph& g, Tag tag) {
williamr@2:     typedef typename Visitor::event_filter Category;
williamr@2:     typedef typename graph_detail::is_same<Category, Tag>::is_same_tag
williamr@2:       IsSameTag;
williamr@2:     detail::invoke_dispatch(vlist.first, x, g, IsSameTag());
williamr@2:     invoke_visitors(vlist.second, x, g, tag);
williamr@2:   }
williamr@2: #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
williamr@2:   template <class Visitor, class T, class Graph, class Tag>
williamr@2:   inline void
williamr@2:   invoke_visitors(base_visitor<Visitor>& vis, T x, Graph& g, Tag) {
williamr@2:     typedef typename Visitor::event_filter Category;
williamr@2:     typedef typename graph_detail::is_same<Category, Tag>::is_same_tag
williamr@2:       IsSameTag;
williamr@2:     Visitor& v = static_cast<Visitor&>(vis);
williamr@2:     detail::invoke_dispatch(v, x, g, IsSameTag());
williamr@2:   }
williamr@2: #else
williamr@2:   template <class Visitor, class T, class Graph, class Tag>
williamr@2:   inline void
williamr@2:   invoke_visitors(Visitor& v, T x, Graph& g, Tag) {
williamr@2:     typedef typename Visitor::event_filter Category;
williamr@2:     typedef typename graph_detail::is_same<Category, Tag>::is_same_tag
williamr@2:       IsSameTag;
williamr@2:     detail::invoke_dispatch(v, x, g, IsSameTag());
williamr@2:   }
williamr@2: #endif
williamr@2: 
williamr@2:   //========================================================================
williamr@2:   // predecessor_recorder
williamr@2: 
williamr@2:   template <class PredecessorMap, class Tag>
williamr@2:   struct predecessor_recorder
williamr@2:     : public base_visitor<predecessor_recorder<PredecessorMap, Tag> >
williamr@2:   {
williamr@2:     typedef Tag event_filter;
williamr@2:     predecessor_recorder(PredecessorMap pa) : m_predecessor(pa) { }
williamr@2:     template <class Edge, class Graph>
williamr@2:     void operator()(Edge e, const Graph& g) {
williamr@2:       put(m_predecessor, target(e, g), source(e, g));
williamr@2:     }
williamr@2:     PredecessorMap m_predecessor;
williamr@2:   };
williamr@2:   template <class PredecessorMap, class Tag>
williamr@2:   predecessor_recorder<PredecessorMap, Tag>
williamr@2:   record_predecessors(PredecessorMap pa, Tag) {
williamr@2:     return predecessor_recorder<PredecessorMap, Tag> (pa);
williamr@2:   }
williamr@2: 
williamr@2:   //========================================================================
williamr@2:   // edge_predecessor_recorder
williamr@2: 
williamr@2:   template <class PredEdgeMap, class Tag>
williamr@2:   struct edge_predecessor_recorder
williamr@2:     : public base_visitor<edge_predecessor_recorder<PredEdgeMap, Tag> >
williamr@2:   {
williamr@2:     typedef Tag event_filter;
williamr@2:     edge_predecessor_recorder(PredEdgeMap pa) : m_predecessor(pa) { }
williamr@2:     template <class Edge, class Graph>
williamr@2:     void operator()(Edge e, const Graph& g) {
williamr@2:       put(m_predecessor, target(e, g), e);
williamr@2:     }
williamr@2:     PredEdgeMap m_predecessor;
williamr@2:   };
williamr@2:   template <class PredEdgeMap, class Tag>
williamr@2:   edge_predecessor_recorder<PredEdgeMap, Tag>
williamr@2:   record_edge_predecessors(PredEdgeMap pa, Tag) {
williamr@2:     return edge_predecessor_recorder<PredEdgeMap, Tag> (pa);
williamr@2:   }
williamr@2: 
williamr@2:   //========================================================================
williamr@2:   // distance_recorder
williamr@2: 
williamr@2:   template <class DistanceMap, class Tag>
williamr@2:   struct distance_recorder
williamr@2:     : public base_visitor<distance_recorder<DistanceMap, Tag> >
williamr@2:   {
williamr@2:     typedef Tag event_filter;
williamr@2:     distance_recorder(DistanceMap pa) : m_distance(pa) { }
williamr@2:     template <class Edge, class Graph>
williamr@2:     void operator()(Edge e, const Graph& g) {
williamr@2:       typename graph_traits<Graph>::vertex_descriptor
williamr@2:         u = source(e, g), v = target(e, g);
williamr@2:       put(m_distance, v, get(m_distance, u) + 1);
williamr@2:     }
williamr@2:     DistanceMap m_distance;
williamr@2:   };
williamr@2:   template <class DistanceMap, class Tag>
williamr@2:   distance_recorder<DistanceMap, Tag>
williamr@2:   record_distances(DistanceMap pa, Tag) {
williamr@2:     return distance_recorder<DistanceMap, Tag> (pa);
williamr@2:   }
williamr@2: 
williamr@2:   //========================================================================
williamr@2:   // time_stamper
williamr@2: 
williamr@2: 
williamr@2:   template <class TimeMap, class TimeT, class Tag>
williamr@2:   struct time_stamper
williamr@2:     : public base_visitor<time_stamper<TimeMap, TimeT, Tag> >
williamr@2:   {
williamr@2:     typedef Tag event_filter;
williamr@2:     time_stamper(TimeMap pa, TimeT& t) : m_time_pa(pa), m_time(t) { }
williamr@2:     template <class Vertex, class Graph>
williamr@2:     void operator()(Vertex u, const Graph&) {
williamr@2:       put(m_time_pa, u, ++m_time);
williamr@2:     }
williamr@2:     TimeMap m_time_pa;
williamr@2:     TimeT& m_time;
williamr@2:   };
williamr@2:   template <class TimeMap, class TimeT, class Tag>
williamr@2:   time_stamper<TimeMap, TimeT, Tag>
williamr@2:   stamp_times(TimeMap pa, TimeT& time_counter, Tag) {
williamr@2:     return time_stamper<TimeMap, TimeT, Tag>(pa, time_counter);
williamr@2:   }
williamr@2: 
williamr@2:   //========================================================================
williamr@2:   // property_writer
williamr@2: 
williamr@2:   template <class PA, class OutputIterator, class Tag>
williamr@2:   struct property_writer
williamr@2:     : public base_visitor<property_writer<PA, OutputIterator, Tag> >
williamr@2:   {
williamr@2:     typedef Tag event_filter;
williamr@2: 
williamr@2:     property_writer(PA pa, OutputIterator out) : m_pa(pa), m_out(out) { }
williamr@2: 
williamr@2:     template <class T, class Graph>
williamr@2:     void operator()(T x, Graph&) { *m_out++ = get(m_pa, x); }
williamr@2:     PA m_pa;
williamr@2:     OutputIterator m_out;
williamr@2:   };
williamr@2:   template <class PA, class OutputIterator, class Tag>
williamr@2:   property_writer<PA, OutputIterator, Tag>
williamr@2:   write_property(PA pa, OutputIterator out, Tag) {
williamr@2:     return property_writer<PA, OutputIterator, Tag>(pa, out);
williamr@2:   }
williamr@2: 
williamr@2: #define BOOST_GRAPH_EVENT_STUB(Event,Kind)                                 \
williamr@2:     typedef ::boost::Event Event##_type;                                   \
williamr@2:     template<typename Visitor>                                             \
williamr@2:     Kind##_visitor<std::pair<detail::functor_to_visitor<Event##_type,      \
williamr@2:                                                      Visitor>, Visitors> > \
williamr@2:     do_##Event(Visitor visitor)                                            \
williamr@2:     {                                                                      \
williamr@2:       typedef std::pair<detail::functor_to_visitor<Event##_type, Visitor>, \
williamr@2:                         Visitors> visitor_list;                            \
williamr@2:       typedef Kind##_visitor<visitor_list> result_type;                    \
williamr@2:       return result_type(visitor_list(visitor, m_vis));                    \
williamr@2:     }
williamr@2: 
williamr@2: } /* namespace boost */
williamr@2: 
williamr@2: #endif