+(* Compare two actions (for sorting). *)
+let action_compare (n1,_,_,_,_,_,_) (n2,_,_,_,_,_,_) = compare n1 n2
+
+let chars c n =
+ let str = String.create n in
+ for i = 0 to n-1 do
+ String.unsafe_set str i c
+ done;
+ str
+
+let spaces n = chars ' ' n