From e2bb0e93cbfad0b2b216603c932fd770fc8e037e Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Sat, 14 Jun 2014 14:30:15 +0200
Subject: [PATCH] CCArray.find

---
 core/CCArray.ml  | 8 ++++++++
 core/CCArray.mli | 4 ++++
 2 files changed, 12 insertions(+)

diff --git a/core/CCArray.ml b/core/CCArray.ml
index 2838c7cc..7d2d6dfa 100644
--- a/core/CCArray.ml
+++ b/core/CCArray.ml
@@ -57,6 +57,14 @@ let reverse_in_place a =
     a = [| 6;5;4;3;2;1 |]
 *)
 
+let find f a =
+  let rec find i =
+    if i = Array.length a then None
+    else match f a.(i) with
+      | Some _ as res -> res
+      | None -> find (i+1)
+  in find 0
+
 let filter_map f a =
   let rec aux acc i =
     if i = Array.length a
diff --git a/core/CCArray.mli b/core/CCArray.mli
index e31ce665..5ed08de1 100644
--- a/core/CCArray.mli
+++ b/core/CCArray.mli
@@ -41,6 +41,10 @@ val filter : ('a -> bool) -> 'a t -> 'a t
 val reverse_in_place : 'a t -> unit
 (** Reverse the array in place *)
 
+val find : ('a -> 'b option) -> 'a t -> 'b option
+(** [find f a] returns [Some y] if there is an element [x] such
+    that [f x = Some y], else it returns [None] *)
+
 val filter_map : ('a -> 'b option) -> 'a t -> 'b t
 (** Map each element into another value, or discard it *)