1 files changed, 30 insertions, 3 deletions
diff --git a/lib/util.ml b/lib/util.ml
index adf3c757a1..625ceed870 100644
--- a/lib/util.ml
+++ b/lib/util.ml
@@ -69,6 +69,14 @@ let intersect l1 l2 =
 let subtract l1 l2 =
   if l2 = [] then l1 else List.filter (fun x -> not (List.mem x l2)) l1
 
+let list_chop n l = 
+  let rec chop_aux acc = function
+    | (0, l2) -> (List.rev acc, l2)
+    | (n, (h::t)) -> chop_aux (h::acc) (pred n, t)
+    | (_, []) -> failwith "chop_list"
+  in 
+  chop_aux [] (n,l)
+ 
 (* Arrays *)
 
 let array_exists f v = 
@@ -78,6 +86,13 @@ let array_exists f v =
   in 
   exrec ((Array.length v)-1) 
 
+let array_for_all f v = 
+  let rec allrec = function
+    | -1 -> true
+    | n -> (f v.(n)) && (allrec (n-1))
+  in 
+  allrec ((Array.length v)-1) 
+
 let array_for_all2 f v1 v2 =
   let rec allrec = function
     | -1 -> true
@@ -86,15 +101,20 @@ let array_for_all2 f v1 v2 =
   let lv1 = Array.length v1 in
   lv1 = Array.length v2 && allrec (pred lv1) 
 
+let array_hd v = 
+  match Array.length v with
+    | 0 -> failwith "array_hd"
+    | _ -> v.(0)
+
 let array_tl v = 
   match Array.length v with
     | 0 -> failwith "array_tl"
     | n -> Array.sub v 1 (pred n)
 
-let array_hd v = 
+let array_last v =
   match Array.length v with
-    | 0 -> failwith "array_hd"
-    | _ -> v.(0)
+    | 0 -> failwith "aray_last"
+    | n -> v.(pred n)
 
 let array_cons e v = Array.append [|e|] v
 
@@ -125,6 +145,13 @@ let array_list_of_tl v =
 let array_map_to_list f v =
   List.map f (Array.to_list v)
 
+let array_chop n v =
+  let vlen = Array.length v in
+  if n > vlen then 
+    failwith "chop_vect"
+  else 
+    (Array.sub v 0 n, Array.sub v n (vlen-n))
+
 (* Functions *)
 
 let compose f g x = f (g x)