(* 

 * UChar - Unicode (ISO-UCS) characters

 * Copyright (C) 2002, 2003 Yamagata Yoriyuki

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version,

 * with the special exception on linking described in file LICENSE.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *)

type t = int

exception Out_of_range

external unsafe_chr_of_uint : int -> t = "%identity"

external uint_code : t -> int = "%identity"

let char_of c = 

  if c >= 0 && c < 0x100 then Char.chr c else raise Out_of_range

let of_char = Char.code

let code c = if c >= 0 then c else raise Out_of_range

let chr n =

  if n >= 0 && n lsr 31 = 0 then n else invalid_arg "UChar.chr"

let chr_of_uint n = if n lsr 31 = 0 then n else invalid_arg "UChar.uint_chr"

let eq (u1 : t) (u2 : t) = u1 = u2

let compare u1 u2 =

  let sgn = (u1 lsr 16) - (u2 lsr 16) in

  if sgn = 0 then (u1 land 0xFFFF) -  (u2 land 0xFFFF) else sgn

type uchar = t

let int_of_uchar u = uint_code u

let uchar_of_int n = chr_of_uint n