new function list_mapi_acc

diff --git a/helm/software/components/extlib/hExtlib.ml b/helm/software/components/extlib/hExtlib.ml
index 8451eb6b86c69eb435adf561a7290497cc353ff3..49d28bbb91733a50e785d3c17388a58cb7c7b32a 100644 (file)
--- a/helm/software/components/extlib/hExtlib.ml
+++ b/helm/software/components/extlib/hExtlib.ml
@@ -148,6 +148,14 @@ let list_mapi f l =
      aux 0 l
 ;;
 
+let list_mapi_acc f a l =
+  let rec aux k a res = function
+    | [] -> a, List.rev res
+    | h::tl -> let a,h = f h k a in aux (k+1) a (h::res) tl
+  in
+   aux 0 a [] l
+;;
+
 let list_index p =
  let rec aux n =
   function

diff --git a/helm/software/components/extlib/hExtlib.mli b/helm/software/components/extlib/hExtlib.mli
index a0b85ca4f9b1e27ece951ec169a86ef0ca6f32e8..63bfc25f1bbc8789e1c22399ad1a86baf2cf063c 100644 (file)
--- a/helm/software/components/extlib/hExtlib.mli
+++ b/helm/software/components/extlib/hExtlib.mli
@@ -95,6 +95,8 @@ val list_findopt: ('a -> int -> 'b option) -> 'a list -> 'b option
 val flatten_map: ('a -> 'b list) -> 'a list -> 'b list
 val list_last: 'a list -> 'a
 val list_mapi: ('a -> int -> 'b) -> 'a list -> 'b list
+val list_mapi_acc: 
+      ('a -> int -> 'acc -> 'acc * 'b) -> 'acc -> 'a list -> 'acc * 'b list 
 (* Finds the zero based index of the first element that satisfies a predicate*)
 val list_index: ('a -> bool) -> 'a list -> (int * 'a) option
 val sharing_map: ('a -> 'a) -> 'a list -> 'a list