(*
* Global - Mutable global variable
* Copyright (C) 2003 Nicolas Cannasse
*
* 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
*)
exception Global_not_initialized of string
type 'a t = ('a option ref * string)
let empty name = ref None,name
let name = snd
let set (r,_) v = r := Some v
let get (r,name) =
match !r with
| None -> raise (Global_not_initialized name)
| Some v -> v
let undef (r,_) = r := None
let isdef (r,_) = !r <> None
let opt (r,_) = !r