From: Florian Weimer <Florian.Weimer@RUS.Uni-Stuttgart.DE>
Subject: Re: Does a null pointer always raise Constraint_Error?
Date: 13 Dec 2000 15:58:14 +0100
Date: 2000-12-13T15:58:14+01:00 [thread overview]
Message-ID: <tgn1e0mkqh.fsf@mercury.rus.uni-stuttgart.de> (raw)
In-Reply-To: slrn93f1ic.vo.lutz@taranis.iks-jena.de
lutz@iks-jena.de (Lutz Donnerhacke) writes:
> * Ken Garlington wrote:
> >"Lutz Donnerhacke" <lutz@iks-jena.de> wrote in message
> >: * Robert Dewar wrote:
> >: [access to empty arrays represent as Null (System.Address)]
> >: > subtype n is string (1 .. 0);
> >: > type np is access n;
> >: > a, b : np;
> >: >
> >: > if a.all = b.all then ...
> >: >
> >: >it is a common compiler bug to translate this as
> >: >
> >: > for j in n'range loop
> >: > if a.all (j) = b.all (j) ....
> >: >
> >: >and the null loop causes no checks to be made :-)
> Possible, but irrelevant IMHO. Two empty arrays of the same component type
> are equal per definition.
There a two language-defined checks involved prior to the array
comparison. However, 11.6(5) seems to permit the omission of these
checks, but I'm not sure about that.
next prev parent reply other threads:[~2000-12-13 14:58 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.LNX.4.10.10011301306120.793-100000@lexis.di.fct.unl.pt>
[not found] ` <tgzoihpon4.fsf@mercury.rus.uni-stuttgart.de>
[not found] ` <9074fi$93b$1@nnrp1.deja.com>
[not found] ` <3A3253B1.AD8F32CF@ebox.tninet.se>
[not found] ` <90u1vi$uah$1@nnrp1.deja.com>
[not found] ` <90ukfm$c4p$1@nnrp1.deja.com>
2000-12-12 16:23 ` Does a null pointer always raise Constraint_Error? Wayne Magor
2000-12-12 20:27 ` Keith Thompson
2000-12-13 0:46 ` Robert Dewar
2000-12-13 8:58 ` Lutz Donnerhacke
2000-12-13 13:56 ` Ken Garlington
2000-12-13 14:25 ` Lutz Donnerhacke
2000-12-13 14:58 ` Florian Weimer [this message]
2000-12-13 15:17 ` Lutz Donnerhacke
2000-12-13 15:40 ` Robert Dewar
2000-12-13 20:07 ` Florian Weimer
2000-12-14 13:08 ` Robert Dewar
2000-12-14 14:29 ` Ken Garlington
2000-12-15 1:45 ` Robert Dewar
2000-12-13 15:37 ` Robert Dewar
2000-12-12 20:31 ` Keith Thompson
2000-12-13 19:58 ` Florian Weimer
2000-12-13 0:43 ` Robert Dewar
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