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|
(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Damien Doligez, projet Para, INRIA Rocquencourt *)
(* *)
(* Copyright 1997 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the GNU Library General Public License. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Module [Lazy]: deferred computations *)
type 'a status =
| Delayed of (unit -> 'a)
| Value of 'a
| Exception of exn
;;
type 'a t = 'a status ref;;
let force l =
match !l with
| Value v -> v
| Exception e -> raise e
| Delayed f ->
try let v = f () in l := Value v; v
with e -> l := Exception e; raise e
;;
|
