X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;ds=sidebyside;f=helm%2Fsoftware%2Fcomponents%2Fextlib%2FhExtlib.ml;fp=helm%2Fsoftware%2Fcomponents%2Fextlib%2FhExtlib.ml;h=237d4e77f34e2e1611fa8d04ab5639932fd24f2b;hb=acc309665418f646857b8c246ef037d71fdea705;hp=cccb467674e22415b59de320e72cbbe845812142;hpb=8b299ba276e095f0fa929a4818d00d253be4c591;p=helm.git

diff --git a/helm/software/components/extlib/hExtlib.ml b/helm/software/components/extlib/hExtlib.ml
index cccb46767..237d4e77f 100644
--- a/helm/software/components/extlib/hExtlib.ml
+++ b/helm/software/components/extlib/hExtlib.ml
@@ -211,6 +211,19 @@ let sharing_map f l =
   if !unchanged then l else l1
 ;;
         
+let sharing_map_acc f acc l =
+  let unchanged = ref true in
+  let final_acc = ref acc in
+  let rec aux b acc = function
+    | [] as t -> unchanged := b; final_acc := acc; t
+    | he::tl ->
+        let acc, he1 = f acc he in
+        he1 :: aux (b && he1 == he) acc tl
+  in
+  let l1 = aux true acc l in
+  !final_acc, if !unchanged then l else l1
+;;
+
 let rec list_uniq ?(eq=(=)) = function 
   | [] -> []
   | h::[] -> [h]