% generates a .dot file for graphviz to create a graph

dotgen(Edge):- dotgen_head, dotgen_body(Edge), dotgen_foot.

dotgen_head :-
        write('digraph G {'),nl,
        write(' rankdir=LR'),nl,
        write(' node [shape=box]'),nl.
dotgen_foot:-
        write('}'),nl.

dotgen_body(Edge) :- 
	Edge = EdgePredicateName / EdgeNumberOfArgs,
	functor(EdgePredicate,EdgePredicateName,EdgeNumberOfArgs),
	EdgePredicate,
	EdgePredicate =.. [_,FromNode, ToNode|_],

	write('"'), 
	write(FromNode),
	write('"'), 
	write(' -> '), 
	write('"'),
	write(ToNode),
	write('"'), nl,	
	fail.
dotgen_body(_).