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(**************************************************************************)
(* *)
(* Copyright (C) 2012 Pietro Abate <pietro.abate@pps.jussieu.fr> *)
(* *)
(* This library is free software: you can redistribute it and/or modify *)
(* it under the terms of the GNU Lesser General Public License as *)
(* published by the Free Software Foundation, either version 3 of the *)
(* License, or (at your option) any later version. A special linking *)
(* exception to the GNU Lesser General Public License applies to this *)
(* library, see the COPYING file for more information. *)
(**************************************************************************)
module type UniqueType = sig
type t
type v
val create : v -> t
val value : t -> v
val uid : t -> int
end
module type OrderedType = sig type t val compare : t -> t -> int end
(* This module gives to each value a single id *)
module Make ( S : OrderedType ) : UniqueType with type v = S.t = struct
module VMap = Map.Make(S)
type v = S.t
type t = Hash of (v * int)
let gentag =
let r = ref 0 in
fun () -> incr r; !r
let cons = ref VMap.empty
let create v =
try Hash(v,VMap.find v !cons) with
Not_found -> begin
let i = gentag () in
cons := VMap.add v i !cons;
Hash (v,i)
end
let value = function Hash (v,_) -> v
let uid = function Hash (_,i) -> i
end
|
