More cleanup, fix things broken in last cleanup

demo.scm

@@ -18,18 +18,14 @@
 		   (set-node-color (cdr pair) red)
 		   (cdr pair))))
        graph))
-
-(define djikstra-generator
+(define (make-graph-generator f)
   (generator
-   (djikstra graph 90 9 (lambda (visited heap)
+   (f graph 90 9 (lambda (visited heap)
 			  (yield (color-graph graph visited heap))))
    #f))
-(define a*-generator
-  (generator
-   (a* graph 90 9 (lambda (visited heap)
-		    (yield (color-graph graph visited heap))))
-   #f))
 
+(define djikstra-generator (make-graph-generator djikstra))
+(define a*-generator (make-graph-generator a*))
 (write-graphs-to-file "djikstra.webp" djikstra-generator)
 (write-graphs-to-file "astar.webp" a*-generator)