(**************************************************************************)
(*                                                                        *)
(*                                 OCaml                                  *)
(*                                                                        *)
(*             Xavier Leroy, projet Cristal, INRIA Rocquencourt           *)
(*                                                                        *)
(*   Copyright 1996 Institut National de Recherche en Informatique et     *)
(*     en Automatique.                                                    *)
(*                                                                        *)
(*   All rights reserved.  This file is distributed under the terms of    *)
(*   the GNU Lesser General Public License version 2.1, with the          *)
(*   special exception on linking described in the file LICENSE.          *)
(*                                                                        *)
(**************************************************************************)

(* Access paths *)

type t =
  | Pident of Ident.t
  (** Examples: x, List, int *)
  | Pdot of t * string
  (** Examples: List.map, Float.Array *)
  | Papply of t * t
  (** Examples: Set.Make(Int), Map.Make(Set.Make(Int)) *)
  | Pextra_ty of t * extra_ty
  (** [Pextra_ty (p, extra)] are additional paths of types
      introduced by specific OCaml constructs. See below.
  *)
and extra_ty =
  | Pcstr_ty of string
  (** [Pextra_ty (p, Pcstr_ty c)] is the type of the inline record for
      constructor [c] inside type [p].

      For example, in
      {[
        type 'a t = Nil | Cons of {hd : 'a; tl : 'a t}
      ]}

      The inline record type [{hd : 'a; tl : 'a t}] cannot
      be named by the user in the surface syntax, but internally
      it has the path
        [Pextra_ty (Pident `t`, Pcstr_ty "Cons")].
  *)
  | Pext_ty
  (** [Pextra_ty (p, Pext_ty)] is the type of the inline record for
      the extension constructor [p].

      For example, in
      {[
        type exn += Error of {loc : loc; msg : string}
      ]}

      The inline record type [{loc : loc; msg : string}] cannot
      be named by the user in the surface syntax, but internally
      it has the path
        [Pextra_ty (Pident `Error`, Pext_ty)].
  *)

val same: t -> t -> bool
val equiv: (Ident.Unscoped.t * Ident.Unscoped.t) list -> t -> t -> bool
(** See ident.mli for the distrinction between [same] and [equiv] *)

val compare: t -> t -> int
val compare_extra: extra_ty -> extra_ty -> int
val find_free_opt: Ident.t list -> t -> Ident.t option
val exists_free: Ident.t list -> t -> bool
val scope: t -> int

val subst: (Ident.t * t) list -> t -> t
val check_for_unbound_unscoped_idents:
  Ident.Unscoped.Set.t -> t -> Ident.Unscoped.t option

val flatten : t -> [ `Contains_apply | `Ok of Ident.t * string list ]

val scrape_extra_ty: t -> t
(** Removes surrounding `Pext_ty` constructors from a path *)

val name: ?paren:(string -> bool) -> t -> string
    (* [paren] tells whether a path suffix needs parentheses *)
val head: t -> Ident.t

val print: t Format_doc.printer

val heads: t -> Ident.t list

val last: t -> string

val is_constructor_typath: t -> bool

module Map : Map.S with type key = t
module Set : Set.S with type elt = t
