]> matita.cs.unibo.it Git - helm.git/commitdiff
Type for list_index improved.
authorClaudio Sacerdoti Coen <claudio.sacerdoticoen@unibo.it>
Sat, 25 Apr 2009 20:28:07 +0000 (20:28 +0000)
committerClaudio Sacerdoti Coen <claudio.sacerdoticoen@unibo.it>
Sat, 25 Apr 2009 20:28:07 +0000 (20:28 +0000)
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
     | [], _ -> ()