From 8a73ba595908d900861231210b350734eed31177 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Thu, 1 Jan 1970 00:00:00 +0000
Subject: [PATCH] Added functions sort_uniq and uniq.

---
 lib/diskimage_utils.ml  | 13 +++++++++++++
 lib/diskimage_utils.mli |  8 ++++++++
 2 files changed, 21 insertions(+)

diff --git a/lib/diskimage_utils.ml b/lib/diskimage_utils.ml
index 6abb608..3ea53b7 100644
--- a/lib/diskimage_utils.ml
+++ b/lib/diskimage_utils.ml
@@ -263,6 +263,19 @@ let group_by ?(cmp = Pervasives.compare) ls =
   let ls' = List.rev ls' in
   List.map (fun (x, xs) -> x, List.rev xs) ls'
 
+let rec uniq ?(cmp = Pervasives.compare) = function
+  | [] -> []
+  | [x] -> [x]
+  | x :: y :: xs when cmp x y = 0 ->
+      uniq (x :: xs)
+  | x :: y :: xs ->
+      x :: uniq (y :: xs)
+
+let sort_uniq ?cmp xs =
+  let xs = ExtList.List.sort ?cmp xs in
+  let xs = uniq ?cmp xs in
+  xs
+
 let rec range a b =
   if a < b then a :: range (a+1) b
   else []
diff --git a/lib/diskimage_utils.mli b/lib/diskimage_utils.mli
index 6f813fe..9eccf64 100644
--- a/lib/diskimage_utils.mli
+++ b/lib/diskimage_utils.mli
@@ -144,6 +144,14 @@ val canonical_uuid : string -> string
 val group_by : ?cmp:('a -> 'a -> int) -> ('a * 'b) list -> ('a * 'b list) list
 (** Group a sorted list of pairs by the first element of the pair. *)
 
+val sort_uniq : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list
+(** [sort_uniq xs] returns the list [xs], sorted and with all duplicate
+    elements removed. *)
+
+val uniq : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list
+(** [uniq xs] removes adjacent duplicate elements from a list, like
+    the Unix uniq(1) command. *)
+
 val range : int -> int -> int list
 (** [range a b] returns the list of integers [a <= i < b].
     If [a >= b] then the empty list is returned.
-- 
1.8.3.1