(***********************************************************************)
(*                                                                     *)
(*                               TAToo                                 *)
(*                                                                     *)
(*                     Kim Nguyen, LRI UMR8623                         *)
(*                   Université Paris-Sud & CNRS                       *)
(*                                                                     *)
(*  Copyright 2010-2012 Université Paris-Sud and Centre National de la *)
(*  Recherche Scientifique. All rights reserved.  This file is         *)
(*  distributed under the terms of the GNU Lesser General Public       *)
(*  License, with the special exception on linking described in file   *)
(*  ../LICENSE.                                                        *)
(*                                                                     *)
(***********************************************************************)

include Hcons.Make (struct
  include String
  let hash s = Hashtbl.hash s
  let equal s1 s2 = s1 = s2
end)

let print pp s = Format.fprintf pp "%s" s.node

let of_string = make
let to_string = node

let document = of_string "#document"
let text = of_string "#text"
let comment = of_string "#comment"
let nil = of_string "#"

let attribute t = of_string ( "@" ^ (to_string t))
let processing_instruction t = of_string ( "?" ^ (to_string t))

let remove_prefix t =
  let s = to_string t in
  let lens = String.length s in
  if lens == 0 then t
  else
    if s.[0] == '@' || s.[0] == '?' then
      of_string (String.sub s 1 (lens-1))
    else
      t