(** A view of the top-level of a regex. This type is unstable and may change *)

module Cset : sig
  type t = Cset.t

  module Range : sig
    type t

    val first : t -> Char.t
    val last : t -> Char.t
  end

  val view : t -> Range.t list
end

module Sem : sig
  type t =
    [ `Longest
    | `Shortest
    | `First
    ]
end

module Rep_kind : sig
  type t =
    [ `Greedy
    | `Non_greedy
    ]
end

type t =
  | Set of Cset.t
  | Sequence of Ast.t list
  | Alternative of Ast.t list
  | Repeat of Ast.t * int * int option
  | Beg_of_line
  | End_of_line
  | Beg_of_word
  | End_of_word
  | Not_bound
  | Beg_of_str
  | End_of_str
  | Last_end_of_line
  | Start
  | Stop
  | Sem of Sem.t * Ast.t
  | Sem_greedy of Rep_kind.t * Ast.t
  | Group of string option * Ast.t
  | No_group of Ast.t
  | Nest of Ast.t
  | Case of Ast.t
  | No_case of Ast.t
  | Intersection of Ast.t list
  | Complement of Ast.t list
  | Difference of Ast.t * Ast.t
  | Pmark of Pmark.t * Ast.t

val view : Ast.t -> t