X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fextlib%2FhExtlib.ml;h=8451eb6b86c69eb435adf561a7290497cc353ff3;hb=11e495dda047bcdfa4267c06cad2d074fcffe3e3;hp=4a228b232736e916f4960048dfd9d15f0146e8eb;hpb=2b837ca9e298eb44eee95d9ca0e331c577785dcb;p=helm.git

diff --git a/helm/software/components/extlib/hExtlib.ml b/helm/software/components/extlib/hExtlib.ml
index 4a228b232..8451eb6b8 100644
--- a/helm/software/components/extlib/hExtlib.ml
+++ b/helm/software/components/extlib/hExtlib.ml
@@ -217,6 +217,18 @@ let rec filter_map f =
       | None -> filter_map f tl
       | Some v -> v :: filter_map f tl)
 
+let filter_map_acc f acc l =
+  let acc, res = 
+   List.fold_left
+    (fun (acc, res) t ->
+       match f acc t with
+       | None -> acc, res
+       | Some (acc, x) -> acc, x::res)
+    (acc,[]) l
+  in
+   acc, List.rev res
+;;
+
 let list_rev_map_filter f l =
    let rec aux a = function
       | []       -> a
@@ -267,11 +279,11 @@ let rec list_findopt f l =
   in
   aux 0 l
 
-let split_nth msg n l =
+let split_nth n l =
   let rec aux acc n l =
     match n, l with
     | 0, _ -> List.rev acc, l
-    | n, [] -> raise (Failure ("HExtlib.split_nth: " ^ msg))
+    | n, [] -> raise (Failure "HExtlib.split_nth")
     | n, hd :: tl -> aux (hd :: acc) (n - 1) tl in
   aux [] n l