[Caml-list] Forcing a Map type: setting the value type

[Hugo Ferreira <hmf@inescporto.pt>]

Hello,

I would like to make a Map with the key = int and
and the value also equal to int. Is this possible?
The example below does not work.

TIA,
Hugo F.


# module Domains : Map.S with type key = int
                          with type (+'a) t = int = Map.Make( Int );;
Error: Signature mismatch:
        Modules do not match:
          sig
            type key = Int.t
            type 'a t = 'a Map.Make(Int).t
            val empty : 'a t
            val is_empty : 'a t -> bool
            val add : key -> 'a -> 'a t -> 'a t
            val find : key -> 'a t -> 'a
            val remove : key -> 'a t -> 'a t
            val mem : key -> 'a t -> bool
            val iter : (key -> 'a -> unit) -> 'a t -> unit
            val map : ('a -> 'b) -> 'a t -> 'b t
            val mapi : (key -> 'a -> 'b) -> 'a t -> 'b t
            val fold : (key -> 'a -> 'b -> 'b) -> 'a t -> 'b -> 'b
            val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int
            val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
          end
        is not included in
          sig
            type key = int
            type 'a t = int
            val empty : 'a t
            val is_empty : 'a t -> bool
            val add : key -> 'a -> 'a t -> 'a t
            val find : key -> 'a t -> 'a
            val remove : key -> 'a t -> 'a t
            val mem : key -> 'a t -> bool
            val iter : (key -> 'a -> unit) -> 'a t -> unit
            val map : ('a -> 'b) -> 'a t -> 'b t
            val mapi : (key -> 'a -> 'b) -> 'a t -> 'b t
            val fold : (key -> 'a -> 'b -> 'b) -> 'a t -> 'b -> 'b
            val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int
            val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
          end
        Type declarations do not match:
          type 'a t = 'a Map.Make(Int).t
        is not included in
          type 'a t = int