more tests

src/data/CCDeque.ml

@@ -108,6 +108,11 @@ let peek_front d = match d.cur.cell with
   | Two (x,_) -> x
   | Three (x,_,_) -> x
 
+(*$T
+  of_list [1;2;3] |> peek_front = 1
+  try (ignore (of_list [] |> peek_front); false) with Empty -> true
+  *)
+
 let peek_back d =
   if is_empty d then raise Empty
   else match d.cur.prev.cell with
@@ -116,6 +121,11 @@ let peek_back d =
     | Two (_,x) -> x
     | Three (_,_,x) -> x
 
+(*$T
+  of_list [1;2;3] |> peek_back = 3
+  try (ignore (of_list [] |> peek_back); false) with Empty -> true
+*)
+
 let take_back_node_ n = match n.cell with
   | Zero -> assert false
   | One x -> n.cell <- Zero; x
@@ -141,12 +151,20 @@ let take_back d =
     x
   )
 
+(*$T
+  let q = of_list [1;2;3] in take_back q = 3 && to_list q = [1;2]
+  *)
+
 let take_front_node_ n = match n.cell with
   | Zero -> assert false
   | One x -> n.cell <- Zero; x
   | Two (x,y) -> n.cell <- One y; x
   | Three (x,y,z) -> n.cell <- Two (y,z); x
 
+(*$T
+  let q = of_list [1;2;3] in take_front q = 1 && to_list q = [2;3]
+  *)
+
 let take_front d =
   if is_empty d then raise Empty
   else if d.cur.prev == d.cur

src/data/CCDeque.mli

@@ -48,7 +48,8 @@ val compare : ?cmp:('a -> 'a -> int) -> 'a t -> 'a t -> int
     @since NEXT_RELEASE *)
 
 val length : 'a t -> int
-(** Number of elements (linear) *)
+(** Number of elements
+    used to be linear time, now constant time *)
 
 val push_front : 'a t -> 'a -> unit
 (** Push value at the front *)
@@ -130,6 +131,8 @@ val to_rev_list : 'a t -> 'a list
 (** Efficient conversion to list, in reverse order
     @since NEXT_RELEASE *)
 
+(** {2 print} *)
+
 type 'a printer = Format.formatter -> 'a -> unit
 
 val print : 'a printer -> 'a t printer