more fixes

library/assoc.factor

@@ -56,8 +56,11 @@ USE: stack
     #! [ [ 1 | "one" ] [ 2 | "two" ] [ 3 | "three" ] ]
     assoc* dup [ cdr ] when ;
 
+: acons ( value key alist -- alist )
+    >r swons r> cons ;
+
 : set-assoc ( value key alist -- alist )
     #! Sets the key in the alist. Does not modify the existing
     #! list by consing a new key/value pair onto the alist. The
     #! newly-added pair 'shadows' the previous value.
-    >r swons r> [ dupd car= not ] subset cons ;
+    [ dupd car = not ] subset acons ;