From adcff57e4c40f7176aec594cff66bb842f8adb59 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sun, 15 Mar 2015 22:20:01 +0100
Subject: [PATCH] add `--` to CCFQueue

---
 src/data/CCFQueue.ml  | 9 +++++++++
 src/data/CCFQueue.mli | 5 +++++
 2 files changed, 14 insertions(+)

diff --git a/src/data/CCFQueue.ml b/src/data/CCFQueue.ml
index 638a1617..96c62b92 100644
--- a/src/data/CCFQueue.ml
+++ b/src/data/CCFQueue.ml
@@ -358,3 +358,12 @@ let rec _equal_klist eq l1 l2 = match l1(), l2() with
       eq x1 x2 && _equal_klist eq l1' l2'
 
 let equal eq q1 q2 = _equal_klist eq (to_klist q1) (to_klist q2)
+
+let (--) a b =
+  let rec up_to q a b = if a = b
+    then snoc q a
+    else up_to (snoc q a) (a+1) b
+  and down_to q a b = if a = b then snoc q a
+    else down_to (snoc q a) (a-1) b
+  in
+  if a <= b then up_to empty a b else down_to empty a b
diff --git a/src/data/CCFQueue.mli b/src/data/CCFQueue.mli
index 397155c1..3c5d4ab4 100644
--- a/src/data/CCFQueue.mli
+++ b/src/data/CCFQueue.mli
@@ -114,6 +114,7 @@ val map : ('a -> 'b) -> 'a t -> 'b t
 (** Map values *)
 
 val (>|=) : 'a t -> ('a -> 'b) -> 'b t
+(** Synonym to {!map} *)
 
 val size : 'a t -> int
 (** Number of elements in the queue (constant time) *)
@@ -138,3 +139,7 @@ val of_seq : 'a sequence -> 'a t
 val to_klist : 'a t -> 'a klist
 val of_klist : 'a klist -> 'a t
 
+val (--) : int -> int -> int t
+(** [a -- b] is the integer range from [a] to [b], both included.
+    @since NEXT_RELEASE *)
+