instance fixed

[helm.git] / helm / software / components / extlib / hExtlib.ml

diff --git a/helm/software/components/extlib/hExtlib.ml b/helm/software/components/extlib/hExtlib.ml
index 8451eb6b86c69eb435adf561a7290497cc353ff3..237d4e77f34e2e1611fa8d04ab5639932fd24f2b 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
@@ -203,6 +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]
@@ -229,6 +250,18 @@ let filter_map_acc f acc l =
    acc, List.rev res
 ;;
 
+let filter_map_monad f acc l =
+  let acc, res = 
+   List.fold_left
+    (fun (acc, res) t ->
+       match f acc t with
+       | acc, None -> acc, res
+       | acc, Some x -> acc, x::res)
+    (acc,[]) l
+  in
+   acc, List.rev res
+;;
+
 let list_rev_map_filter f l =
    let rec aux a = function
       | []       -> a