X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=components%2Fextlib%2FhExtlib.ml;h=073c5695959480e657070af45a68ec3029132ef6;hb=86458c2afc0d02aad6dc22267793b7538dc475d0;hp=c0364315a62c018923f2c9e76873a35087c15fd2;hpb=2499f5fdcf4dbfecc6f4fafe925b24ae76f14be8;p=helm.git

diff --git a/components/extlib/hExtlib.ml b/components/extlib/hExtlib.ml
index c0364315a..073c56959 100644
--- a/components/extlib/hExtlib.ml
+++ b/components/extlib/hExtlib.ml
@@ -153,6 +153,28 @@ let rec filter_map f =
       | None -> filter_map f tl
       | Some v -> v :: filter_map f tl)
 
+let list_rev_map_filter f l =
+   let rec aux a = function
+      | []       -> a
+      | hd :: tl -> 
+         begin match f hd with
+	    | None   -> aux a tl
+	    | Some b -> aux (b :: a) tl 
+         end
+   in 
+   aux [] l
+
+let list_rev_map_filter_fold f v l =
+   let rec aux v a = function
+      | []       -> v, a
+      | hd :: tl -> 
+         begin match f v hd with
+	    | v, None   -> aux v a tl
+	    | v, Some b -> aux v (b :: a) tl 
+         end
+   in 
+   aux v [] l
+
 let list_concat ?(sep = []) =
   let rec aux acc =
     function