]> matita.cs.unibo.it Git - helm.git/blobdiff - helm/software/components/extlib/hExtlib.ml
Inductive definitions are now interpreted (but records are not interpreted yet).
[helm.git] / helm / software / components / extlib / hExtlib.ml
index 523913cbfcda4e6e2e501103d068d1462ff9232e..3ef795e9fca4badc9299cd2a0f4207fe1af2afa5 100644 (file)
@@ -148,6 +148,16 @@ let list_mapi f l =
      aux 0 l
 ;;
 
+let list_index p =
+ let rec aux n =
+  function
+     [] -> None
+   | he::_ when p he -> Some (n,he)
+   | _::tl -> aux (n + 1) tl
+ in
+  aux 0
+;;
+
 let rec list_iter_default2 f l1 def l2 = 
   match l1,l2 with
     | [], _ -> ()