X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fextlib%2FhExtlib.ml;h=3ef795e9fca4badc9299cd2a0f4207fe1af2afa5;hb=6b3242efcd29ea188ef09b445985abb06c5fad3a;hp=523913cbfcda4e6e2e501103d068d1462ff9232e;hpb=987627a48b2a3c2345d1af2c2a6b1ab78aa90b58;p=helm.git

diff --git a/helm/software/components/extlib/hExtlib.ml b/helm/software/components/extlib/hExtlib.ml
index 523913cbf..3ef795e9f 100644
--- a/helm/software/components/extlib/hExtlib.ml
+++ b/helm/software/components/extlib/hExtlib.ml
@@ -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
     | [], _ -> ()