(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2012     *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

module type HashedType =
sig
  type t
  val compare : t -> t -> int
  (** Total ordering *)
  val hash : t -> int
  (** Hashing function compatible with [compare], i.e. [compare x y = 0] implies
      [hash x = hash y]. *)
end

(** Hash maps are maps that take advantage of having a hash on keys. This is
    essentially a hash table, except that it uses purely functional maps instead
    of arrays.

    CAVEAT: order-related functions like [fold] or [iter] do not respect the
    provided order anymore! It's your duty to do something sensible to prevent
    this if you need it. In particular, [min_binding] and [max_binding] are now
    made meaningless.
*)
module Make(M : HashedType) : CMap.ExtS with type key = M.t
