add Fake module

src/hc.ml

@@ -19,33 +19,14 @@ module type Cache = sig
 
   val clear : 'a t -> unit
 
-  val reset : 'a t -> unit
-
-  val copy : 'a t -> 'a t
-
   val add : 'a t -> key -> 'a -> unit
 
-  val remove : 'a t -> key -> unit
-
   val find : 'a t -> key -> 'a
 
-  val find_opt : 'a t -> key -> 'a option
-
-  val find_all : 'a t -> key -> 'a list
-
-  val replace : 'a t -> key -> 'a -> unit
-
-  val mem : 'a t -> key -> bool
-
   val length : 'a t -> int
 
   val stats : 'a t -> Hashtbl.statistics
 
-  val add_seq : 'a t -> (key * 'a) Seq.t -> unit
-
-  val replace_seq : 'a t -> (key * 'a) Seq.t -> unit
-
-  val of_seq : (key * 'a) Seq.t -> 'a t
 end
 
 module Mk (Cache : Cache) : sig
@@ -92,3 +73,25 @@ end
 module MakeStrong (H : Hashtbl.HashedType) = struct
   include Mk (Hashtbl.Make (H))
 end
+
+module Fake (H : Hashtbl.HashedType) = struct
+
+  include (Mk (struct
+    type key = H.t
+    type 'a t = | Unit
+
+    let create (_size : int) = Unit
+    let clear Unit = ()
+    let add (Unit : 'a t) (_v: key) (_ : 'a) = ()
+    let find Unit (_v: key) = raise Not_found
+    let length Unit = 0
+    let stats Unit = {
+      Hashtbl.num_bindings = 0;
+      num_buckets = 0;
+      max_bucket_length = 0;
+      bucket_histogram = [||]
+    }
+  end
+  ))
+
+end

test/test.ml

@@ -36,7 +36,7 @@ let rec get_fibo n =
     let b = get_fibo (n - 2) in
     node (extract a + extract b) a b
 
-let _ =
+let () =
   (* 1 *)
   let n1 = leaf 1 in
   let n2 = leaf 2 in