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From: Jacob Sparre Andersen <sparre@nbi.dk>
Subject: Re: not null
Date: Thu, 05 Mar 2009 18:20:01 +0100
Date: 2009-03-05T18:20:01+01:00	[thread overview]
Message-ID: <ygewsb3opj2.fsf@sparre-andersen.dk> (raw)
In-Reply-To: 4282b420-25a7-47d5-859e-427485dc8bbd@a5g2000pre.googlegroups.com

Adam Beneschan wrote:
> Jacob Sparre Andersen wrote:

>> > Whatever mistakes a programmer could in the actual Ada language
>> > make by forgetting to check whether an access value is null, he
>> > could make in the above example by forgetting to check the
>> > Present discriminant.
>>
>> No.  The _compiler_ checks the discriminant.  The programmer will
>> get a Constraint_Error if he tries to use "Ref" while "Present" is
>> false.
>
> It also checks access values and raises Constraint_Error if they're
> null, so I don't understand what your point is.

Neither do I.  Must have been sleepy.

Greetings,

Jacob
-- 
A password should be like a toothbrush. Use it every day;
change it regularly; and DON'T share it with friends.



  reply	other threads:[~2009-03-05 17:20 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-04 14:44 not null Georg Bauhaus
2009-03-04 14:56 ` Hyman Rosen
2009-03-04 15:22   ` Georg Bauhaus
2009-03-04 16:16     ` Adam Beneschan
2009-03-05 14:24       ` Georg Bauhaus
2009-03-05 16:07         ` Adam Beneschan
2009-03-06  1:07       ` Hibou57 (Yannick Duchêne)
2009-03-04 16:09   ` Adam Beneschan
2009-03-04 20:38     ` Dmitry A. Kazakov
2009-03-05  1:54       ` Adam Beneschan
2009-03-05  8:42         ` Dmitry A. Kazakov
2009-03-05  1:32     ` Brian Drummond
2009-03-05  1:47       ` Adam Beneschan
2009-03-05 11:32         ` Brian Drummond
2009-03-05 15:06           ` Dmitry A. Kazakov
2009-03-05 13:57         ` Georg Bauhaus
2009-03-05 19:53       ` Jack Mitchell
2009-03-05  8:49     ` Jacob Sparre Andersen
2009-03-05 16:10       ` Adam Beneschan
2009-03-05 17:20         ` Jacob Sparre Andersen [this message]
2009-03-06  1:04     ` Hibou57 (Yannick Duchêne)
2009-03-06 12:01     ` Harald Korneliussen
2009-03-06 12:43       ` Jacob Sparre Andersen
2009-03-06 13:05         ` Harald Korneliussen
2009-03-06 15:21       ` Dmitry A. Kazakov
2009-03-06 16:59         ` Harald Korneliussen
2009-03-06 17:48           ` Dmitry A. Kazakov
2009-03-06 20:05             ` Georg Bauhaus
2009-03-06 21:31               ` Dmitry A. Kazakov
2009-03-04 16:19   ` Robert A Duff
2009-03-04 20:39 ` Colin Paul Gloster
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