From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: GNAT GPL 2013 bug?
Date: Mon, 12 Aug 2013 15:12:51 -0500
Date: 2013-08-12T15:12:51-05:00 [thread overview]
Message-ID: <kubfk3$krm$1@loke.gir.dk> (raw)
In-Reply-To: k71biho5pjg7.16zreugtnwyc6$.dlg@40tude.net
"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
news:k71biho5pjg7.16zreugtnwyc6$.dlg@40tude.net...
> On Fri, 09 Aug 2013 16:04:02 -0400, Robert A Duff wrote:
...
> BTW, why Ada 2005 used incompatible null-exclusion instead of compatible
> null-permission, e.g.
>
> procedure P (X : null or access T); -- I accept null
>
> or something like that?
Because that would make the syntax for named access and anonymous access
different, or would simply move the incompatibility to named access types.
The difference between the default behavior for anonymous and named access
in Ada 95 was unjustifiable once we had null exclusions. That meant we had
to break something, and the least painful was the implicit "not null" on
controlling access parameters (something best avoided anyway, IMHO).
Randy.
next prev parent reply other threads:[~2013-08-12 20:12 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-09 9:47 GNAT GPL 2013 bug? Dmitry A. Kazakov
2013-08-09 10:38 ` sbelmont700
2013-08-09 11:01 ` Dmitry A. Kazakov
2013-08-09 11:06 ` sbelmont700
2013-08-09 11:36 ` Dmitry A. Kazakov
2013-08-09 15:48 ` Adam Beneschan
2013-08-09 16:11 ` Simon Wright
2013-08-09 16:52 ` Adam Beneschan
2013-08-09 18:25 ` Simon Wright
2013-08-09 18:39 ` Adam Beneschan
2013-08-09 19:28 ` Adam Beneschan
2013-08-09 20:05 ` Robert A Duff
2013-08-09 20:30 ` Adam Beneschan
2013-08-09 21:35 ` Simon Wright
2013-08-10 15:10 ` Shark8
2013-08-09 16:03 ` Simon Wright
2013-08-09 18:55 ` Randy Brukardt
2013-08-09 19:27 ` Dmitry A. Kazakov
2013-08-09 20:04 ` Robert A Duff
2013-08-10 6:51 ` Dmitry A. Kazakov
2013-08-12 16:52 ` Adam Beneschan
2013-08-12 17:03 ` Dmitry A. Kazakov
2013-08-12 17:20 ` Adam Beneschan
2013-08-12 18:34 ` Dmitry A. Kazakov
2013-08-12 20:12 ` Randy Brukardt [this message]
2013-08-13 6:43 ` Dmitry A. Kazakov
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