add CCArray.to_string

src/core/CCArray.ml

@@ -540,6 +540,18 @@ let pp_i ?(sep=", ") pp_item out a =
     pp_item k out a.(k)
   done
 
+let to_string ?(sep=", ") item_to_string a =
+  Array.to_list a
+  |> List.map item_to_string
+  |> String.concat sep
+
+(*$= to_string & ~printer:(fun s -> s)
+  (to_string string_of_int [|1;2;3;4;5;6|]) "1, 2, 3, 4, 5, 6"
+  (to_string string_of_int [||]) ""
+  (to_string ~sep:" " string_of_int [|1;2;3;4;5;6|]) "1 2 3 4 5 6"
+  (to_string string_of_int [|1|]) "1"
+*)
+
 let to_seq a k = iter k a
 
 let to_gen a =

src/core/CCArray.mli

@@ -244,6 +244,11 @@ val random_choose : 'a t -> 'a random_gen
 (** [random_choose a rs] randomly chooses an element of [a].
     @raise Not_found if the array/slice is empty. *)
 
+val to_string : ?sep:string -> ('a -> string) -> 'a array -> string
+(** [to_string ~sep item_to_string a] print [a] to a string using [sep] as a separator
+    between elements of [a].
+    @since NEXT_RELEASE *)
+
 val to_seq : 'a t -> 'a sequence
 (** [to_seq a] returns a [sequence] of the elements of an array [a].
     The input array [a] is shared with the sequence and modification of it will result