(* This file is free software, part of containers. See file "license" for more details. *)

(** {1 Wrapper around Set} *)

type 'a sequence = ('a -> unit) -> unit
type 'a printer = Format.formatter -> 'a -> unit

module type S = sig
  include Set.S

  val of_seq : elt sequence -> t

  val add_seq : t -> elt sequence -> t
  (** @since 0.14 *)

  val to_seq : t -> elt sequence

  val of_list : elt list -> t

  val add_list : t -> elt list -> t
  (** @since 0.14 *)

  val to_list : t -> elt list

  val pp :
    ?start:string -> ?stop:string -> ?sep:string ->
    elt printer -> t printer
end

module Make(O : Map.OrderedType) = struct
  include Set.Make(O)

  let add_seq set seq =
    let set = ref set in
    seq (fun x -> set := add x !set);
    !set

  let of_seq s = add_seq empty s

  let to_seq s yield = iter yield s

  let add_list = List.fold_left (fun set x -> add x set)

  let of_list l = add_list empty l

  let to_list = elements

  let pp ?(start="") ?(stop="") ?(sep=", ") pp_x fmt m =
    Format.pp_print_string fmt start;
    let first = ref true in
    iter
      (fun x ->
         if !first then first := false
         else (
           Format.pp_print_string fmt sep;
           Format.pp_print_cut fmt ()
         );
         pp_x fmt x)
      m;
    Format.pp_print_string fmt stop
end