X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=components%2Fextlib%2FhExtlib.ml;h=3cc6c9bb5c0bc876f74d35de8868f3231a56c14e;hb=ce800b0b7acf3940cad3afc5b1d2296155affb1c;hp=57511db0e5205d7a61bee0f074f3631d88815914;hpb=cbcd34fe15122eb9835a5226b98be1050b097d6a;p=helm.git

diff --git a/components/extlib/hExtlib.ml b/components/extlib/hExtlib.ml
index 57511db0e..3cc6c9bb5 100644
--- a/components/extlib/hExtlib.ml
+++ b/components/extlib/hExtlib.ml
@@ -135,6 +135,10 @@ let is_alphanum c = is_alpha c || is_digit c
 
 (** {2 List processing} *)
 
+let flatten_map f l =
+  List.flatten (List.map f l)
+;;
+
 let rec list_uniq ?(eq=(=)) = function 
   | [] -> []
   | h::[] -> [h]
@@ -168,6 +172,14 @@ let rec list_findopt f l =
   in
   aux 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")
+    | n, hd :: tl -> aux (hd :: acc) (n - 1) tl in
+  aux [] n l
+
 (** {2 File predicates} *)
 
 let is_dir fname =
@@ -310,13 +322,16 @@ let find ?(test = fun _ -> true) path =
 let safe_remove fname = if Sys.file_exists fname then Sys.remove fname
 
 let is_dir_empty d =
- let od = Unix.opendir d in
- let rec aux () =
-  let name = Unix.readdir od in
-  if name <> "." && name <> ".." then false else aux () in
- let res = try aux () with End_of_file -> true in
-  Unix.closedir od;
-  res
+ try
+  let od = Unix.opendir d in
+  let rec aux () =
+   let name = Unix.readdir od in
+   if name <> "." && name <> ".." then false else aux () in
+  let res = try aux () with End_of_file -> true in
+   Unix.closedir od;
+   res
+ with
+  Unix.Unix_error _ -> true (* raised by Unix.opendir, we hope :-) *)
 
 let safe_rmdir d = try Unix.rmdir d with Unix.Unix_error _ -> ()