From: stt@henning.camb.inmet.com (Tucker Taft)
Subject: Re: Ada Objects Help!
Date: Fri, 27 Jan 1995 19:58:54 GMT
Date: 1995-01-27T19:58:54+00:00 [thread overview]
Message-ID: <D32y67.78C@inmet.camb.inmet.com> (raw)
In-Reply-To: D30tDn.41x@world.std.com
In article <D30tDn.41x@world.std.com>,
Robert A Duff <bobduff@world.std.com> wrote:
> ...
>By the way, dispatching on result is an interesting twist that most OOP
>languages don't have:
>
> function Union(X, Y: Set) return Set;
> function Empty_Set return Set;
>
> X: Set'Class := ...;
> Y: Set'Class := Union(X, Empty_Set);
>The appropriate version of function Empty_Set to call is determined (at
>run time) based on the tag of Y, since Empty_Set itself doesn't have any
^^ "X"
>controlling parameters.
Although I presume Bob meant "X" in the above paragraph,
you actually *can* use the left-hand side of an assignment statement
(rather than an initialization) to control the dispatching.
For example, presuming Y was declared as above, we can later
assign into Y again as follows:
Y := Union(Empty_Set, Empty_Set);
In this example, Y is the only thing with a pre-determined tag, and it
controls all dispatching.
>- Bob
-Tucker Taft stt@inmet.com
Intermetrics, Inc.
next prev parent reply other threads:[~1995-01-27 19:58 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <3f9g1u$j4m@nps.navy.mil>
[not found] ` <D2H5un.FEr@nntpa.cb.att.com>
[not found] ` <3fcs59$70s@nps.navy.mil>
[not found] ` <3ff186$c19@gnat.cs.nyu.edu>
1995-01-17 17:57 ` ADA Objects Help! Mats Weber
1995-01-18 17:47 ` Robert Dewar
1995-01-20 16:04 ` Mats Weber
1995-01-21 18:59 ` Robert Dewar
1995-01-23 12:03 ` Robb Nebbe
1995-01-25 20:44 ` Mats Weber
1995-01-25 20:44 ` Mats Weber
1995-01-27 4:03 ` Robert Dewar
1995-01-26 3:36 ` swdecato
[not found] ` <3fhggr$11dp@watnews1.watson.ibm.com>
[not found] ` <Mats.Weber-1901951739360001@mlma11.matrix.ch>
1995-01-20 17:22 ` Norman H. Cohen
1995-01-23 16:37 ` Mats Weber
1995-01-25 20:44 ` Mats Weber
1995-01-27 4:05 ` Robert Dewar
1995-01-19 11:57 ` Robert M. Wilkinson
1995-01-22 18:06 ` Robert Dewar
1995-01-24 22:18 ` Norman H. Cohen
1995-01-25 1:26 ` swdecato
1995-01-25 18:18 ` Bob Kitzberger
1995-01-25 20:11 ` Bob Kitzberger
1995-01-26 15:31 ` Norman H. Cohen
[not found] ` <D330pK.M1@nntpa.cb.att.com>
1995-01-28 21:46 ` John DiCamillo
1995-01-30 14:13 ` David Emery
1995-01-30 22:50 ` Subject/Object Confusion Syndrome [was: Ada Objects Help] John Volan
1995-02-01 14:33 ` Norman H. Cohen
[not found] ` <D3DpJu.4nK@swlvx2.msd.ray.com>
[not found] ` <D3H7J3.B2x@inmet.camb.inmet.com>
1995-02-06 10:32 ` Robb Nebbe
[not found] ` <3gu21g$ch@portal.gmu.edu>
1995-02-06 14:01 ` John Volan
1995-02-01 22:37 ` Maarten Landzaat
[not found] ` <3h1ahp$gf5@gnat.cs.nyu.edu>
[not found] ` <3h3jmp$1h1@Starbase.NeoSoft.COM>
1995-02-07 14:39 ` John Volan
1995-02-09 2:25 ` David Weller
1995-01-29 18:19 ` ADA Objects Help! mat
[not found] ` <1995Feb5.180601@hobbit>
1995-02-07 23:04 ` Subject/Object Confusion Syndrome [was: Ada Objects Help] John Volan
1995-01-25 9:48 ` ADA Objects Help! mat
1995-01-23 10:01 ` calling syntax (was Re: Ada Objects) Robb Nebbe
1995-01-23 18:08 ` John DiCamillo
1995-01-23 23:47 ` ADA Objects Help! Ed Osinski
1995-01-25 6:19 ` David O'Brien
[not found] ` <1995Jan16.132400@lglsun.epfl.ch>
[not found] ` <131279@cup.portal.com>
1995-01-20 16:52 ` Ada " Robert Dewar
1995-01-22 18:30 ` Tucker Taft
1995-01-24 22:09 ` Jacob Sparre Andersen
1995-01-26 16:20 ` Robert A Duff
1995-01-27 17:04 ` Robert A Duff
1995-01-27 19:58 ` Tucker Taft [this message]
1995-01-20 17:41 ` Mark S. Hathaway
1995-01-23 10:41 ` Robb Nebbe
1995-01-23 11:53 ` Stephane Barbey
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