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From: stefan-lucks@see-the.signature
Newsgroups: comp.lang.ada
Subject: Re: and then... (a curiosity)
Date: Thu, 4 Sep 2008 14:12:57 +0200
Organization: Bauhaus-Universitaet Weimar
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Date: 2008-09-04T14:12:57+02:00
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> > 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!  ------