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