improve graphs a bit.

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@2285 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

library/wundgraphs.yap

@@ -13,6 +13,8 @@
 	    wundgraph_edges/2,
 	    wundgraph_neighbors/3,
 	    wundgraph_neighbours/3,
+	    wundgraph_wneighbors/3,
+	    wundgraph_wneighbours/3,
 	    wdgraph_to_wundgraph/2,
 	    wundgraph_to_undgraph/2,
 	    wundgraph_min_tree/3,
@@ -32,7 +34,9 @@
 	    wdgraph_min_path/5 as wundgraph_min_path,
 	    wdgraph_min_paths/3 as wundgraph_min_paths,
 	    wdgraph_max_path/5 as wundgraph_max_path,
-	    wdgraph_path/3 as wundgraph_path]).
+	    wdgraph_path/3 as wundgraph_path,
+	    wdgraph_reachable/3 as wundgraph_reachable
+	   ]).
 
 :- use_module( library(wdgraphs),
 	   [
@@ -95,6 +99,25 @@ wundgraph_neighbours(V,Vertices,Children) :-
 	).
 wundgraph_neighbors(V,Vertices,Children) :-
 	wdgraph_neighbors(V,Vertices,Children0),
+	(
+	    wdel_me(Children0,V,Children)
+	->
+	    true
+	;
+	    Children = Children0
+	).
+
+wundgraph_wneighbours(V,Vertices,Children) :-
+	wdgraph_wneighbours(V,Vertices,Children0),
+	(
+	    wdel_me(Children0,V,Children)
+	->
+	    true
+	;
+	    Children = Children0
+	).
+wundgraph_wneighbors(V,Vertices,Children) :-
+	wdgraph_wneighbors(V,Vertices,Children0),
 	(
 	    del_me(Children0,V,Children)
 	->
@@ -104,7 +127,7 @@ wundgraph_neighbors(V,Vertices,Children) :-
 	).
 
 del_me([], _, []).
-del_me([K-_|Children], K1, NewChildren) :-
+del_me([K|Children], K1, NewChildren) :-
 	( K == K1 ->
 	    Children = NewChildren
 	;
@@ -116,6 +139,19 @@ del_me([K-_|Children], K1, NewChildren) :-
 	    compact(Children, MoreChildren)
 	).
 
+wdel_me([], _, []).
+wdel_me([K-A|Children], K1, NewChildren) :-
+	( K == K1 ->
+	    Children = NewChildren
+	;
+	    K @< K1 ->
+	    NewChildren = [K-A|ChildrenLeft],
+	    wdel_me(Children, K1, ChildrenLeft)
+	;
+	    NewChildren = [K-A|MoreChildren],
+	    compact(Children, MoreChildren)
+	).
+
 wundgraph_del_edge(Vs0,V1,V2,K,VsF) :-
 	wdgraph_del_edge(Vs0,V1,V2,K,Vs1),
 	wdgraph_del_edge(Vs1,V2,V1,K,VsF).