more updates to meld.

packages/meld/examples/pagerank/l4.meld

@@ -0,0 +1,7 @@
+%edge(0,1).
+%edge(0,4).
+%edge(1,4).
+%edge(1,2).
+edge(2,3).
+edge(2,4).
+edge(3,4).

packages/meld/examples/pagerank/pagerank.meld

@@ -1,20 +1,24 @@
 
 type rank(node, int, float).
+type reachable(node, node).
 type calcRank(node, int, sum float).
-type persistent numPages(node, int).
+% type persistent numPages(node,  int).
+type persistent numPages(node, sum int).
 type numLinks(node, sum int).
+type path(node, node).
 
 const damping = 0.85.
 const num_iterations = 4.
 % extern float to_float(int).
 % extern float float_abs(float).
 
-rank(A, 0, 1.0 / to_float(T)) :- numPages(A, T).
+rank(A, 0, 1.0 / to_float(T)) :- numPages(A,T).
 rank(A, I, V) :-
+	numPages(A, Ps),
 	calcRank(A, I, T),
 	Before = I - 1,
 	rank(A, Before, VOld),
-	V = damping + (1.0 - damping) * T,
+	V = (damping + (1.0 - damping) * T)/to_float(Ps),
 	I =< num_iterations.
 
 % //float_abs((damping + (1.0 - damping) * T) - VOld) > 0.001.
@@ -27,8 +31,17 @@ calcRank(A, I + 1, O / to_float(C)) :-
 numLinks(A, 1) :-
 	edge(A,B).
 
-numPages(A, 1) :-
+numPages(A, 1) :- path(A,_).
+
+path(A, B) :-
+	edge(A,B).
+path(A, B) :-
 	edge(B,A).
-
+path(A, B) :-
+	edge(A,C),
+	path(C,B).
+path(A, B) :-
+	edge(C,A),
+	path(C,B).
 
 

packages/meld/meldc.yap

@@ -186,8 +186,8 @@ compile_goal((forall G then Do), Goals, Gs, Head) :- !,
 	listtobody(BLF2, Body),
 	listtobody(DelBLF2, DelBody),
 	% done
-	assert(meld_program:(run(NG) :- Body)),
-	assert(meld_program:(run(delete(DelNG)) :- DelBody)).
+	assert_static(meld_program:(run(NG) :- Body)),
+	assert_static(meld_program:(run(delete(DelNG)) :- DelBody)).
 compile_goal(Goal, Goals, Gs, Head) :-
 	collect_body(Gs, Goals, BLF, BL1),
 	copy_term(h(Head,BLF,BL1,Goal), h(Head,DelBLF,DelBL1,DelGoal)),
@@ -198,8 +198,8 @@ compile_goal(Goal, Goals, Gs, Head) :-
 	reorder_builtins(DelGoal, DelBLF, DelBLF2),
 	listtobody(BLF2, Body),
 	listtobody(DelBLF2, DelBody),
-	assert(meld_program:(run(Goal) :- Body)),
-	assert(meld_program:(run(deleted(DelGoal)) :- DelBody)).
+	assert_static(meld_program:(run(Goal) :- Body)),
+	assert_static(meld_program:(run(deleted(DelGoal)) :- DelBody)).
 
 % quantified variables should not leave the scope of the forall.
 quantified_vars(G,Extern,NG) :-

packages/meld/meldi.yap

@@ -23,7 +23,8 @@
 	[
 	 nb_queue/1,
 	 nb_queue_enqueue/2,
-	 nb_queue_dequeue/2
+	 nb_queue_dequeue/2,
+	 nb_queue_replace/3
 	]).
 
 
@@ -35,7 +36,7 @@
 live :-
 	repeat,
 	( pop(Goal) ->
-	  format('-~w~n',[Goal]),
+%	  format('<- ~w~n',[Goal]),
 	  run(Goal),
 	  fail
 	;
@@ -50,6 +51,7 @@ done :-
 done :-
 	current_predicate(meld_program:P),
 	P \= run/1,
+	P \= trace/2,
 %	P \= neighbor/2,
 %	P \= root/1,
 	listing(meld_program:P),
@@ -58,9 +60,18 @@ done.
 
 
 delete(Fact) :-
+	once(retract(meld_program:Fact)),
 	nb_getval(meld_queue, Queue),
-	retract(meld_program:Fact),
-	nb_queue_enqueue(Queue, deleted(Fact)).
+	(
+%	 nb:nb_queue_show(Queue, L ), writeln(show:Fact:L),
+	 nb_queue_replace(Queue, Fact, [] ),
+%	 format('R ~w~n', [Fact]),
+	 deleted(Fact)
+	->
+	 true
+	;
+	 nb_queue_enqueue(Queue, deleted(Fact))
+	).
 
 pop(Goal) :-
 	nb_getval(meld_queue, Queue),
@@ -72,10 +83,12 @@ push(Goal) :-
 	increase_reference_count(Ref),
 	fail.
 push(Goal) :-
-	format('+~w~n',[Goal]),
+%	format('-> ~w~n',[Goal]),
 	nb_getval(meld_queue, Queue), !,
 	assert(meld_program:Goal),
-	nb_queue_enqueue(Queue, Goal).
+	nb_queue_enqueue(Queue, Goal),
+%	 nb:nb_queue_show(Queue, L ), writeln(show:Goal:L),
+	fail.
 
 
 % create a queue
@@ -118,16 +131,17 @@ sum(Skel,Arg,Goal) :-
 	copy_term(Skel, NGoal),
 	meld_program:Skel, !,
 	arg(Arg, Skel, A0),
-	delete(Skel),
 	arg(Arg, Goal, A),
 	AN is A0+A,
+	AN \= A0,
+	delete(Skel),
 	arg(Arg, NGoal, AN),
-	format('S ~w~n',[Goal]),
+%	format('S ~w~n',[NGoal-Skel]),
 	push(NGoal).
 sum(_Skel,_Arg,Goal) :-
-	format('S ~w~n',[Goal]),
-	assert(meld_program:Goal),
-	fail.
+%	format('S ~w~n',[Goal]),
+	push(Goal).
+
 
 clean(Skel) :-
 %	format('D~w~n',[Skel]),
@@ -239,11 +253,12 @@ delete_from_max(Goal) :-
 
 delete_from_sum(Skel,Arg,Goal) :-
 	copy_term(Skel, NGoal),
-	meld_program:Skel,
+	once(meld_program:Skel),
 	arg(Arg, Skel, A0),
-	delete(Skel),
 	arg(Arg, Goal, A),
 	AN is A0-A,
+	AN \= A0,
+	delete(Skel),
 	arg(Arg, NGoal, AN),
 	push(NGoal).
 

packages/meld/meldp.yap

@@ -21,3 +21,4 @@ trace(A,B) :- !,
 	trace.
 
 
+run([]) :- fail.