1(* 2 * Copyright (c) 1997-1999 Massachusetts Institute of Technology 3 * Copyright (c) 2003, 2007-14 Matteo Frigo 4 * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 * 20 *) 21 22(* repository of unique tokens *) 23 24type unique = Unique of int 25 26let make = 27 let id = ref 0 in 28 fun () -> begin 29 id := !id + 1; 30 Unique !id 31 end 32 33let same (Unique a) (Unique b) = 34 a = b 35 36