X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;ds=inline;f=components%2Fextlib%2FhExtlib.ml;h=07886f2690e8eaba64137d434f330793c2423e04;hb=9333fdbe385f6e80b272b194e88001f28dbc8d73;hp=d4572789ad55f39795d000fd09192e839cfee02f;hpb=ad17757edcc6cf75be576268fab8cf52751d679a;p=helm.git

diff --git a/components/extlib/hExtlib.ml b/components/extlib/hExtlib.ml
index d4572789a..07886f269 100644
--- a/components/extlib/hExtlib.ml
+++ b/components/extlib/hExtlib.ml
@@ -164,6 +164,17 @@ let list_rev_map_filter f l =
    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
@@ -203,6 +214,16 @@ let is_dir fname =
     (Unix.stat fname).Unix.st_kind = Unix.S_DIR
   with Unix.Unix_error _ -> false
 
+let writable_dir path =
+  try
+    let file = path ^ "/prova_matita" in
+    let oc = open_out file in
+    close_out oc;
+    Sys.remove file;
+    true
+  with Sys_error _ -> false
+
+
 let is_regular fname =
   try
     (Unix.stat fname).Unix.st_kind = Unix.S_REG