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From: stefan-lucks@see-the.signature
Subject: Re: and then... (a curiosity)
Date: Thu, 4 Sep 2008 14:12:57 +0200
Date: 2008-09-04T14:12:57+02:00	[thread overview]
Message-ID: <Pine.LNX.4.64.0809041404570.22581@medsec1.medien.uni-weimar.de> (raw)
In-Reply-To: <48bf90bf$0$30032$dbd4d001@news.euronet.nl>

> > Thus, "if X/=0 and Y/X<100" should go into the else-branch, instead of 
> > raising an exception.
> > The shortcut version "if X/=0 and then Y/X<100" does exactly the right
> > thing.
> 
> That would be a very bad idea. With that in place, an exception raised by a 
> simple programming error, /any/ programming error, would give control to the 
> else-branch. 

You misread what I wrote. A statement such as "if Y/X<000" should 
definitively propagate an exception for X=0, and I never said anything 
otherwise.

But when "if X/=0 and Y/X<100" propagates an exception for X=0, as, alas, 
done in Ada, something is logically wrong.


BTW, why do you think that an exception, such as a Constraint_Error, 
should logically count as a contradiction? 

Dividing something by zero is undefined, not a contradiction.


-- 
------ Stefan Lucks   --  Bauhaus-University Weimar  --   Germany  ------
               Stefan dot Lucks at uni minus weimar dot de
------  I  love  the  taste  of  Cryptanalysis  in  the  morning!  ------




  reply	other threads:[~2008-09-04 12:12 UTC|newest]

Thread overview: 93+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-29 21:06 and then... (a curiosity) mockturtle
2008-08-29 21:47 ` Samuel Tardieu
2008-08-30 21:28   ` Maciej Sobczak
2008-08-31  8:28     ` Georg Bauhaus
2008-08-31 23:21       ` Ray Blaak
2008-09-01  8:05     ` Martin Krischik
2008-09-01 17:56       ` Ray Blaak
2008-09-02  6:53         ` Martin Krischik
2008-09-02 14:56           ` Adam Beneschan
2008-09-02 16:28             ` Ray Blaak
2008-09-02 16:26           ` Ray Blaak
2008-09-02 20:50             ` Robert A Duff
2008-09-03 12:35               ` Brian Drummond
2008-09-03 15:56                 ` Robert A Duff
2008-09-04 22:09                   ` Brian Drummond
2008-09-03 21:01               ` Vinzent Hoefler
2008-09-02 14:50     ` Adam Beneschan
2008-08-29 22:28 ` Adam Beneschan
2008-08-30  1:06   ` Jeffrey R. Carter
2008-08-30 11:21   ` Dmitry A. Kazakov
2008-08-30 15:35     ` Peter C. Chapin
2008-09-02 15:06       ` Adam Beneschan
2008-09-02  3:41 ` Steve
2008-09-02  7:48   ` stefan-lucks
2008-09-02  8:57     ` Martin Krischik
2008-09-02 10:50       ` stefan-lucks
2008-09-02 10:33         ` Ludovic Brenta
2008-09-02 13:32           ` stefan-lucks
2008-09-02 12:53             ` Ludovic Brenta
2008-09-02 17:32               ` Georg Bauhaus
2008-09-03 13:14               ` stefan-lucks
2008-09-03 12:44                 ` Dmitry A. Kazakov
2008-09-02 13:39             ` stefan-lucks
2008-09-02 13:40             ` stefan-lucks
2008-09-02 16:48             ` Dmitry A. Kazakov
2008-09-02 17:00             ` Keith Thompson
2008-09-02 19:15               ` Simon Wright
2008-09-02 20:37               ` Robert A Duff
2008-09-02 20:58                 ` Jeffrey R. Carter
2008-09-02 21:08                   ` Robert A Duff
2008-09-03 12:24                     ` Pascal Obry
2008-09-02 22:34                   ` Santiago Urueña
2008-09-03  5:56                     ` Robert A Duff
2008-09-03  6:55                       ` Santiago Urueña
2008-09-03 14:14                       ` Adam Beneschan
2008-09-03  0:11                 ` Randy Brukardt
2008-09-02 17:20             ` Georg Bauhaus
2008-09-04  1:05         ` Stephen Leake
2008-09-04  6:45           ` stefan-lucks
2008-09-04  7:35             ` Dmitry A. Kazakov
2008-09-04 12:04               ` stefan-lucks
2008-09-04 13:00                 ` Dmitry A. Kazakov
2008-09-04 19:05                   ` stefan-lucks
2008-09-04 20:28                     ` Dmitry A. Kazakov
2008-09-05  6:57                       ` stefan-lucks
2008-09-05  6:34                         ` Ray Blaak
2008-09-05 14:14                     ` Robert A Duff
2008-09-05 15:04                       ` Dmitry A. Kazakov
2008-09-07 16:45                         ` stefan-lucks
2008-09-05 15:14                       ` Hyman Rosen
2008-09-05 15:59                         ` Adam Beneschan
2008-09-05 16:10                           ` Hyman Rosen
2008-09-07 16:36                       ` stefan-lucks
2008-09-07 16:08                         ` Gautier
2008-09-04  7:39             ` Karel Th�nissen
2008-09-04 12:12               ` stefan-lucks [this message]
2008-09-04 15:13                 ` Georg Bauhaus
2008-09-04 15:16                 ` Karel Th�nissen
2008-09-04 15:42                   ` Dmitry A. Kazakov
2008-09-04 19:27                   ` stefan-lucks
2008-09-04 19:43                     ` stefan-lucks
2008-09-04 19:40                       ` Georg Bauhaus
2008-09-05  7:00                         ` stefan-lucks
2008-09-05  6:35                           ` Ray Blaak
2008-09-04 20:06                       ` Karel Th�nissen
2008-09-05  7:44                         ` stefan-lucks
2008-09-05  6:41                           ` Vinzent Hoefler
2008-09-04 20:09                     ` Karel Th�nissen
2008-09-05  7:25                       ` stefan-lucks
2008-09-05  6:37                         ` Ray Blaak
2008-09-05  8:20                           ` stefan-lucks
2008-09-05 13:57                         ` Robert A Duff
2008-09-04 16:33                 ` Dmitry A. Kazakov
2008-09-04 19:31                   ` stefan-lucks
2008-09-04 19:59                     ` Karel Th�nissen
2008-09-05  7:27                       ` stefan-lucks
2008-09-05  8:38                         ` Ludovic Brenta
2008-09-04 20:17                     ` Dmitry A. Kazakov
2008-09-05 13:26                 ` Robert A Duff
2008-09-05 13:49                   ` Robert A Duff
2008-09-03  1:24     ` Stephen Leake
2008-09-03  3:31       ` tmoran
2008-09-03 13:22       ` stefan-lucks
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