Utils: add Ring.clear

src/lib_stdlib/ring.ml

@@ -40,6 +40,12 @@ let add_and_return_erased r v =
           None in
   add r v ; replaced
 
+let clear r =
+  match !r with
+  | Empty _ -> ()
+  | Inited { data ; _ } ->
+      r := Empty (Array.length data)
+
 let add_list r l = List.iter (add r) l
 
 let last r =

src/lib_stdlib/ring.mli

@@ -27,6 +27,9 @@ val add_and_return_erased : 'a t -> 'a -> 'a option
 (** Adds the values of a list, in order. *)
 val add_list : 'a t -> 'a list -> unit
 
+(** Removes all values in the ring buffer. *)
+val clear : 'a t -> unit
+
 (** Retrieves the most recent value, or [None] when empty. *)
 val last : 'a t -> 'a option