From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: Operation can be dispatching in only one type
Date: Wed, 2 Dec 2009 23:29:49 -0600
Date: 2009-12-02T23:29:49-06:00 [thread overview]
Message-ID: <hf7icf$ffm$1@munin.nbi.dk> (raw)
In-Reply-To: 1jcbtmi5rztyp$.norvlhez9i9$.dlg@40tude.net
"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
news:1jcbtmi5rztyp$.norvlhez9i9$.dlg@40tude.net...
...
> No the problem is whether to treat a call to the body as legal. The
> problem
> is that you could not rely on its contract (out Car), in order to be able
> to decide whether this call would "initialize" the object.
>
> BTW, you consider ":=" as an initialization, but why? Where is a guaranty
> that it initializes the object by a "valid" value? I feel that very
> concept
> is somewhat inconsistent with ADT.
To expand on this point, there are a number of places in Ada where objects
can become "deinitialized". (Compilation strategies can prevent some of
these, but at a cost of more checks with the associated loss of performance.
For instance, Janus/Ada prevents Unchecked_Conversion from deinitializing
scalar objects -- but to do so requires that range/validity checks be done
on the results of some conversions -- hardly "unchecked").
Other places (such as the result of Stream'Read and the results of
Sequential_IO.Read for composite types, and especially abort) can't be
eliminated in any reasonable way.
If you really care about this topic, I suggest you read and reread 13.9.1
until you understand it. (Then join the ARG and explain it to the rest of
us. ;-)! This is not at all a simple topic, and the sort of simple rule used
by Java does little other than give a false sense of security (and a lot of
annoying errors in code that has no problems).
Randy.
next prev parent reply other threads:[~2009-12-03 5:29 UTC|newest]
Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-13 20:12 Operation can be dispatching in only one type xorque
2009-11-13 20:34 ` Dmitry A. Kazakov
2009-11-13 20:43 ` xorque
2009-11-13 21:14 ` Dmitry A. Kazakov
2009-11-13 20:44 ` xorque
2009-11-16 17:43 ` Adam Beneschan
2009-11-16 20:28 ` Dmitry A. Kazakov
2009-11-16 20:32 ` Dmitry A. Kazakov
2009-11-16 21:35 ` Adam Beneschan
2009-11-16 22:28 ` Dmitry A. Kazakov
2009-11-17 22:10 ` Adam Beneschan
2009-11-18 9:46 ` Dmitry A. Kazakov
2009-11-18 16:39 ` Adam Beneschan
2009-11-18 19:21 ` Dmitry A. Kazakov
2009-11-19 0:27 ` Randy Brukardt
2009-11-19 2:11 ` Robert A Duff
2009-11-19 15:57 ` Adam Beneschan
2009-11-19 19:39 ` Robert A Duff
2009-11-19 23:43 ` Randy Brukardt
2009-11-19 8:50 ` Dmitry A. Kazakov
2009-11-19 23:54 ` Randy Brukardt
2009-11-20 8:34 ` Dmitry A. Kazakov
2009-11-20 10:58 ` Jean-Pierre Rosen
2009-11-21 6:02 ` Randy Brukardt
2009-11-21 13:07 ` Dmitry A. Kazakov
2009-11-22 5:45 ` xorque
2009-11-22 11:25 ` Georg Bauhaus
2009-11-22 11:30 ` xorque
2009-11-22 16:25 ` Dmitry A. Kazakov
2009-11-22 16:27 ` xorque
2009-11-22 16:42 ` Dmitry A. Kazakov
2009-11-22 16:52 ` xorque
2009-11-22 17:41 ` Dmitry A. Kazakov
2009-11-22 18:03 ` xorque
2009-11-22 18:08 ` xorque
2009-11-22 18:28 ` Dmitry A. Kazakov
2009-11-22 18:41 ` xorque
2009-11-22 21:47 ` Robert A Duff
2009-11-23 3:42 ` stefan-lucks
2009-11-30 20:36 ` Robert A Duff
2009-11-30 23:54 ` (see below)
2009-12-01 12:13 ` Georg Bauhaus
2009-12-01 12:23 ` Georg Bauhaus
2009-12-01 12:44 ` Georg Bauhaus
2009-12-01 13:48 ` Dmitry A. Kazakov
2009-12-01 15:02 ` Georg Bauhaus
2009-12-01 16:18 ` Dmitry A. Kazakov
2009-12-01 17:52 ` Georg Bauhaus
2009-12-01 18:47 ` Dmitry A. Kazakov
2009-12-01 21:53 ` John B. Matthews
2009-12-02 0:32 ` Georg Bauhaus
2009-12-02 11:18 ` John B. Matthews
2009-12-02 14:29 ` Jean-Pierre Rosen
2009-12-02 15:35 ` Georg Bauhaus
2009-12-02 1:13 ` Georg Bauhaus
2009-12-02 9:07 ` Dmitry A. Kazakov
2009-12-02 12:35 ` John B. Matthews
2009-12-02 13:35 ` Dmitry A. Kazakov
2009-12-03 5:23 ` Randy Brukardt
2009-12-03 20:21 ` John B. Matthews
2009-12-03 5:29 ` Randy Brukardt [this message]
2009-12-03 11:24 ` Georg Bauhaus
2009-12-03 23:08 ` Randy Brukardt
2009-12-04 8:52 ` Dmitry A. Kazakov
2009-12-05 2:45 ` Randy Brukardt
2009-12-05 10:32 ` Dmitry A. Kazakov
2009-12-08 0:19 ` Randy Brukardt
2009-12-08 4:30 ` stefan-lucks
2009-12-08 9:12 ` Dmitry A. Kazakov
2009-12-10 4:09 ` Randy Brukardt
2009-12-11 0:10 ` Robert A Duff
2009-12-08 9:22 ` Dmitry A. Kazakov
2009-12-08 10:06 ` Georg Bauhaus
2009-12-08 10:23 ` Dmitry A. Kazakov
2009-12-08 10:33 ` Georg Bauhaus
2009-12-08 10:49 ` Dmitry A. Kazakov
2009-12-01 23:51 ` Randy Brukardt
2009-11-23 8:52 ` Dmitry A. Kazakov
2009-11-30 20:43 ` Robert A Duff
2009-12-01 9:00 ` Dmitry A. Kazakov
2009-12-01 5:45 ` stefan-lucks
2009-12-01 11:12 ` Dmitry A. Kazakov
2009-12-01 8:01 ` stefan-lucks
2009-12-01 13:37 ` Dmitry A. Kazakov
2009-12-15 23:54 ` Robert A Duff
2009-11-23 7:48 ` Georg Bauhaus
2009-11-23 7:58 ` Georg Bauhaus
2009-11-19 16:04 ` Adam Beneschan
2009-11-19 2:23 ` tmoran
2009-11-19 8:32 ` Dmitry A. Kazakov
-- strict thread matches above, loose matches on Subject: below --
2015-11-23 10:23 operation " Serge Robyns
2015-11-23 11:29 ` Dmitry A. Kazakov
2015-11-23 13:05 ` Serge Robyns
2015-11-23 13:48 ` Dmitry A. Kazakov
2015-11-23 14:16 ` Serge Robyns
2015-11-23 14:59 ` G.B.
2015-11-23 15:52 ` Dmitry A. Kazakov
2015-11-23 17:40 ` Jeffrey R. Carter
2015-11-24 9:08 ` Serge Robyns
2015-11-24 16:44 ` AdaMagica
2015-11-24 17:09 ` Jeffrey R. Carter
2015-11-24 18:37 ` Serge Robyns
2015-11-24 20:18 ` Jeffrey R. Carter
2015-11-24 20:40 ` Serge Robyns
2015-11-24 20:25 ` Niklas Holsti
2015-11-24 21:48 ` Jeffrey R. Carter
2015-11-25 8:24 ` Dmitry A. Kazakov
2015-11-25 11:22 ` Serge Robyns
2015-11-25 17:38 ` Dmitry A. Kazakov
2015-11-26 11:30 ` Serge Robyns
2015-11-26 13:14 ` Dmitry A. Kazakov
2015-11-26 14:27 ` Serge Robyns
2015-11-26 15:16 ` J-P. Rosen
2015-11-26 18:27 ` Serge Robyns
2015-11-26 21:20 ` J-P. Rosen
2015-11-27 8:37 ` Dmitry A. Kazakov
2015-11-27 12:58 ` J-P. Rosen
2015-11-27 13:39 ` Dmitry A. Kazakov
2015-11-30 22:22 ` Randy Brukardt
2015-12-01 8:46 ` Dmitry A. Kazakov
2015-12-01 11:19 ` G.B.
2015-12-01 13:56 ` Dmitry A. Kazakov
2015-12-01 16:05 ` G.B.
2015-12-01 17:58 ` Dmitry A. Kazakov
2015-12-02 13:06 ` G.B.
2015-12-02 13:31 ` Dmitry A. Kazakov
2015-12-02 19:33 ` Randy Brukardt
2015-12-02 19:27 ` Randy Brukardt
2015-11-29 17:59 ` Jacob Sparre Andersen
2015-11-30 22:29 ` Randy Brukardt
2015-11-25 12:27 ` G.B.
2015-11-25 17:25 ` Dmitry A. Kazakov
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