1 | //======================================================================= |
2 | // Copyright 1997, 1998, 1999, 2000 University of Notre Dame. |
3 | // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek |
4 | // |
5 | // Distributed under the Boost Software License, Version 1.0. (See |
6 | // accompanying file LICENSE_1_0.txt or copy at |
7 | // http://www.boost.org/LICENSE_1_0.txt) |
8 | //======================================================================= |
9 | // |
10 | // Revision History: |
11 | // 01 April 2001: Modified to use new <boost/limits.hpp> header. (JMaddock) |
12 | // |
13 | #ifndef BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP |
14 | #define BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP |
15 | |
16 | #include <iosfwd> |
17 | #include <boost/config.hpp> |
18 | #include <boost/type_traits/is_same.hpp> |
19 | #include <boost/mpl/bool.hpp> |
20 | #include <boost/property_map/property_map.hpp> |
21 | #include <boost/graph/graph_traits.hpp> |
22 | #include <boost/limits.hpp> |
23 | |
24 | namespace boost { |
25 | |
26 | // This is a bit more convenient than std::numeric_limits because |
27 | // you don't have to explicitly provide type T. |
28 | template <class T> |
29 | inline T numeric_limits_max(T) { return (std::numeric_limits<T>::max)(); } |
30 | |
31 | //======================================================================== |
32 | // Event Tags |
33 | |
34 | namespace detail { |
35 | // For partial specialization workaround |
36 | enum event_visitor_enum |
37 | { on_no_event_num, |
38 | on_initialize_vertex_num, on_start_vertex_num, |
39 | on_discover_vertex_num, on_finish_vertex_num, on_examine_vertex_num, |
40 | on_examine_edge_num, on_tree_edge_num, on_non_tree_edge_num, |
41 | on_gray_target_num, on_black_target_num, |
42 | on_forward_or_cross_edge_num, on_back_edge_num, on_finish_edge_num, |
43 | on_edge_relaxed_num, on_edge_not_relaxed_num, |
44 | on_edge_minimized_num, on_edge_not_minimized_num |
45 | }; |
46 | |
47 | template<typename Event, typename Visitor> |
48 | struct functor_to_visitor : Visitor |
49 | { |
50 | typedef Event event_filter; |
51 | functor_to_visitor(const Visitor& visitor) : Visitor(visitor) {} |
52 | }; |
53 | |
54 | } // namespace detail |
55 | |
56 | struct on_no_event { enum { num = detail::on_no_event_num }; }; |
57 | |
58 | struct on_initialize_vertex { |
59 | enum { num = detail::on_initialize_vertex_num }; }; |
60 | struct on_start_vertex { enum { num = detail::on_start_vertex_num }; }; |
61 | struct on_discover_vertex { enum { num = detail::on_discover_vertex_num }; }; |
62 | struct on_examine_vertex { enum { num = detail::on_examine_vertex_num }; }; |
63 | struct on_finish_vertex { enum { num = detail::on_finish_vertex_num }; }; |
64 | |
65 | struct on_examine_edge { enum { num = detail::on_examine_edge_num }; }; |
66 | struct on_tree_edge { enum { num = detail::on_tree_edge_num }; }; |
67 | struct on_non_tree_edge { enum { num = detail::on_non_tree_edge_num }; }; |
68 | struct on_gray_target { enum { num = detail::on_gray_target_num }; }; |
69 | struct on_black_target { enum { num = detail::on_black_target_num }; }; |
70 | struct on_forward_or_cross_edge { |
71 | enum { num = detail::on_forward_or_cross_edge_num }; }; |
72 | struct on_back_edge { enum { num = detail::on_back_edge_num }; }; |
73 | struct on_finish_edge { enum { num = detail::on_finish_edge_num }; }; |
74 | |
75 | struct on_edge_relaxed { enum { num = detail::on_edge_relaxed_num }; }; |
76 | struct on_edge_not_relaxed { |
77 | enum { num = detail::on_edge_not_relaxed_num }; }; |
78 | struct on_edge_minimized { enum { num = detail::on_edge_minimized_num }; }; |
79 | struct on_edge_not_minimized { |
80 | enum { num = detail::on_edge_not_minimized_num }; }; |
81 | |
82 | //======================================================================== |
83 | // base_visitor and null_visitor |
84 | |
85 | // needed for MSVC workaround |
86 | template <class Visitor> |
87 | struct base_visitor { |
88 | typedef on_no_event event_filter; |
89 | template <class T, class Graph> |
90 | void operator()(T, Graph&) { } |
91 | }; |
92 | |
93 | struct null_visitor : public base_visitor<null_visitor> { |
94 | typedef on_no_event event_filter; |
95 | template <class T, class Graph> |
96 | void operator()(T, Graph&) { } |
97 | }; |
98 | |
99 | //======================================================================== |
100 | // The invoke_visitors() function |
101 | |
102 | namespace detail { |
103 | template <class Visitor, class T, class Graph> |
104 | inline void invoke_dispatch(Visitor& v, T x, Graph& g, mpl::true_) { |
105 | v(x, g); |
106 | } |
107 | |
108 | template <class Visitor, class T, class Graph> |
109 | inline void invoke_dispatch(Visitor&, T, Graph&, mpl::false_) |
110 | { } |
111 | } // namespace detail |
112 | |
113 | template <class Visitor, class Rest, class T, class Graph, class Tag> |
114 | inline void |
115 | invoke_visitors(std::pair<Visitor, Rest>& vlist, T x, Graph& g, Tag tag) { |
116 | typedef typename Visitor::event_filter Category; |
117 | typedef typename is_same<Category, Tag>::type IsSameTag; |
118 | detail::invoke_dispatch(vlist.first, x, g, IsSameTag()); |
119 | invoke_visitors(vlist.second, x, g, tag); |
120 | } |
121 | template <class Visitor, class T, class Graph, class Tag> |
122 | inline void |
123 | invoke_visitors(Visitor& v, T x, Graph& g, Tag) { |
124 | typedef typename Visitor::event_filter Category; |
125 | typedef typename is_same<Category, Tag>::type IsSameTag; |
126 | detail::invoke_dispatch(v, x, g, IsSameTag()); |
127 | } |
128 | |
129 | //======================================================================== |
130 | // predecessor_recorder |
131 | |
132 | template <class PredecessorMap, class Tag> |
133 | struct predecessor_recorder |
134 | : public base_visitor<predecessor_recorder<PredecessorMap, Tag> > |
135 | { |
136 | typedef Tag event_filter; |
137 | predecessor_recorder(PredecessorMap pa) : m_predecessor(pa) { } |
138 | template <class Edge, class Graph> |
139 | void operator()(Edge e, const Graph& g) { |
140 | put(m_predecessor, target(e, g), source(e, g)); |
141 | } |
142 | PredecessorMap m_predecessor; |
143 | }; |
144 | template <class PredecessorMap, class Tag> |
145 | predecessor_recorder<PredecessorMap, Tag> |
146 | record_predecessors(PredecessorMap pa, Tag) { |
147 | return predecessor_recorder<PredecessorMap, Tag> (pa); |
148 | } |
149 | |
150 | //======================================================================== |
151 | // edge_predecessor_recorder |
152 | |
153 | template <class PredEdgeMap, class Tag> |
154 | struct edge_predecessor_recorder |
155 | : public base_visitor<edge_predecessor_recorder<PredEdgeMap, Tag> > |
156 | { |
157 | typedef Tag event_filter; |
158 | edge_predecessor_recorder(PredEdgeMap pa) : m_predecessor(pa) { } |
159 | template <class Edge, class Graph> |
160 | void operator()(Edge e, const Graph& g) { |
161 | put(m_predecessor, target(e, g), e); |
162 | } |
163 | PredEdgeMap m_predecessor; |
164 | }; |
165 | template <class PredEdgeMap, class Tag> |
166 | edge_predecessor_recorder<PredEdgeMap, Tag> |
167 | record_edge_predecessors(PredEdgeMap pa, Tag) { |
168 | return edge_predecessor_recorder<PredEdgeMap, Tag> (pa); |
169 | } |
170 | |
171 | //======================================================================== |
172 | // distance_recorder |
173 | |
174 | template <class DistanceMap, class Tag> |
175 | struct distance_recorder |
176 | : public base_visitor<distance_recorder<DistanceMap, Tag> > |
177 | { |
178 | typedef Tag event_filter; |
179 | distance_recorder(DistanceMap pa) : m_distance(pa) { } |
180 | template <class Edge, class Graph> |
181 | void operator()(Edge e, const Graph& g) { |
182 | typename graph_traits<Graph>::vertex_descriptor |
183 | u = source(e, g), v = target(e, g); |
184 | put(m_distance, v, get(m_distance, u) + 1); |
185 | } |
186 | DistanceMap m_distance; |
187 | }; |
188 | template <class DistanceMap, class Tag> |
189 | distance_recorder<DistanceMap, Tag> |
190 | record_distances(DistanceMap pa, Tag) { |
191 | return distance_recorder<DistanceMap, Tag> (pa); |
192 | } |
193 | |
194 | //======================================================================== |
195 | // time_stamper |
196 | |
197 | |
198 | template <class TimeMap, class TimeT, class Tag> |
199 | struct time_stamper |
200 | : public base_visitor<time_stamper<TimeMap, TimeT, Tag> > |
201 | { |
202 | typedef Tag event_filter; |
203 | time_stamper(TimeMap pa, TimeT& t) : m_time_pa(pa), m_time(t) { } |
204 | template <class Vertex, class Graph> |
205 | void operator()(Vertex u, const Graph&) { |
206 | put(m_time_pa, u, ++m_time); |
207 | } |
208 | TimeMap m_time_pa; |
209 | TimeT& m_time; |
210 | }; |
211 | template <class TimeMap, class TimeT, class Tag> |
212 | time_stamper<TimeMap, TimeT, Tag> |
213 | stamp_times(TimeMap pa, TimeT& time_counter, Tag) { |
214 | return time_stamper<TimeMap, TimeT, Tag>(pa, time_counter); |
215 | } |
216 | |
217 | //======================================================================== |
218 | // property_writer |
219 | |
220 | template <class PA, class OutputIterator, class Tag> |
221 | struct property_writer |
222 | : public base_visitor<property_writer<PA, OutputIterator, Tag> > |
223 | { |
224 | typedef Tag event_filter; |
225 | |
226 | property_writer(PA pa, OutputIterator out) : m_pa(pa), m_out(out) { } |
227 | |
228 | template <class T, class Graph> |
229 | void operator()(T x, Graph&) { *m_out++ = get(m_pa, x); } |
230 | PA m_pa; |
231 | OutputIterator m_out; |
232 | }; |
233 | template <class PA, class OutputIterator, class Tag> |
234 | property_writer<PA, OutputIterator, Tag> |
235 | write_property(PA pa, OutputIterator out, Tag) { |
236 | return property_writer<PA, OutputIterator, Tag>(pa, out); |
237 | } |
238 | |
239 | //======================================================================== |
240 | // property_put |
241 | |
242 | /** |
243 | * Functor which just sets a given value to a vertex or edge in a property map. |
244 | */ |
245 | |
246 | template <typename PropertyMap, typename EventTag> |
247 | struct property_put |
248 | { |
249 | typedef EventTag event_filter; |
250 | |
251 | property_put (PropertyMap property_map, |
252 | typename property_traits <PropertyMap>::value_type value) : |
253 | property_map_ (property_map), value_ (value) |
254 | {} |
255 | |
256 | template <typename VertexOrEdge, typename Graph> |
257 | void operator() (VertexOrEdge v, const Graph&) |
258 | { |
259 | put (property_map_, v, value_); |
260 | } |
261 | |
262 | private: |
263 | PropertyMap property_map_; |
264 | typename property_traits <PropertyMap>::value_type value_; |
265 | }; |
266 | |
267 | /** |
268 | * Creates a property_put functor which just sets a given value to a vertex or edge. |
269 | * |
270 | * @param property_map Given writeable property map |
271 | * @param value Fixed value of the map |
272 | * @param tag Event Filter |
273 | * @return The functor. |
274 | */ |
275 | |
276 | template <typename PropertyMap, typename EventTag> |
277 | inline property_put <PropertyMap, EventTag> |
278 | put_property (PropertyMap property_map, |
279 | typename property_traits <PropertyMap>::value_type value, |
280 | EventTag) |
281 | { |
282 | return property_put <PropertyMap, EventTag> (property_map, value); |
283 | } |
284 | |
285 | #define BOOST_GRAPH_EVENT_STUB(Event,Kind) \ |
286 | typedef ::boost::Event Event##_type; \ |
287 | template<typename Visitor> \ |
288 | Kind##_visitor<std::pair<detail::functor_to_visitor<Event##_type, \ |
289 | Visitor>, Visitors> > \ |
290 | do_##Event(Visitor visitor) \ |
291 | { \ |
292 | typedef std::pair<detail::functor_to_visitor<Event##_type, Visitor>, \ |
293 | Visitors> visitor_list; \ |
294 | typedef Kind##_visitor<visitor_list> result_type; \ |
295 | return result_type(visitor_list(visitor, m_vis)); \ |
296 | } |
297 | |
298 | } /* namespace boost */ |
299 | |
300 | #endif |
301 | |