module type SF = sig
  type elt
  module S: Set.S with type elt = elt
  val of_list: S.elt list -> S.t
  val map: (S.elt -> S.elt) -> S.t -> S.t
  val ppr: Format.formatter -> S.t -> unit
end

module SetFuns (OT: Map.OrderedType) (SBLE: STRINGABLE with type t = OT.t) : (SF with type elt = OT.t) =
  struct
    module S = Set.Make(OT)

    let of_list l = List.fold_right S.add l S.empty

    (* map from Set to Set of the same type. currying heaven. *)
    let map f s = S.fold (fun x -> S.add (f x)) s S.empty

    let ppr ff s =
      Format.fprintf ff "@[{";
      ppr_list_inners (
        fun ff x ->
          Format.fprintf ff "%s" (SBLE.to_string x);
          ) ff (S.elements s);
          Format.fprintf ff "}@]"
  end