From b5be1d71a9154a19b8d9b03ff017f74046192f37 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Tue, 14 Mar 2017 22:45:11 +0100
Subject: [PATCH] bugfix and test for `CCZipper.is_focused` (closes #102)

---
 src/data/CCZipper.ml | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/data/CCZipper.ml b/src/data/CCZipper.ml
index 44a92db4..b978838b 100644
--- a/src/data/CCZipper.ml
+++ b/src/data/CCZipper.ml
@@ -15,8 +15,12 @@ let to_list (l,r) = List.rev_append l r
 
 let to_rev_list (l,r) = List.rev_append r l
 
+(*$inject
+  let zip_gen = Q.(pair (small_list int)(small_list int))
+  *)
+
 (*$Q
-  Q.(pair (list small_int)(list small_int)) (fun z -> \
+  zip_gen (fun z -> \
     to_list z = List.rev (to_rev_list z))
 *)
 
@@ -51,13 +55,18 @@ let modify f z = match z with
     end
 
 let is_focused = function
-  | _, [] -> true
-  | _ -> false
+  | _, _::_ -> true
+  | _, [] -> false
 
 let focused = function
   | _, x::_ -> Some x
   | _, [] -> None
 
+(*$Q
+  zip_gen (fun g -> \
+    is_focused g = (focused g |> CCOpt.is_some))
+*)
+
 let focused_exn = function
   | _, x::_ -> x
   | _, [] -> raise Not_found