From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: A hole in Ada type safety
Date: Sat, 30 Apr 2011 18:39:58 -0500
Date: 2011-04-30T18:39:58-05:00 [thread overview]
Message-ID: <ipi6kl$cbd$1@munin.nbi.dk> (raw)
In-Reply-To: 87tydfbtp3.fsf@mid.deneb.enyo.de
"Florian Weimer" <fw@deneb.enyo.de> wrote in message
news:87tydfbtp3.fsf@mid.deneb.enyo.de...
...
> And once there is something like this in the language, it is difficult
> to decide if a new addition (such as aliased parameters) make things
> worse or not.
Not sure how something that adds new capabilities only for elementary types
could make anything worse.
We also ran across this particular erroneousness in another case; we decided
that we had to let subprograms trust their constraints (which introduces
some additional erroneousness) as the alternative requires a lot of
additional code for discriminanted parameters. (I forget where the wording
change for that ended up.)
Cases like this is why I like to say that all real Ada programs are
erroneous, so any result is allowed. :-) If you could write an entire
program in SPARK, that could make that statement a falsehood, but the Ada
runtime is most likely erroneous for some reason (interfacing to C tends to
end up erroneous in some cases, for instance). You'd probably need a SPARK
runtime on top of a SPARK OS in order to make a non-erroneous program a
reality.
Randy.
next prev parent reply other threads:[~2011-04-30 23:39 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-30 8:41 A hole in Ada type safety Florian Weimer
2011-04-30 11:56 ` Robert A Duff
2011-04-30 15:27 ` Gavino
2011-04-30 16:16 ` Florian Weimer
2011-04-30 23:39 ` Randy Brukardt [this message]
2011-05-01 10:26 ` Florian Weimer
2011-05-03 1:40 ` Randy Brukardt
2011-05-03 16:57 ` Robert A Duff
2011-05-07 9:09 ` Florian Weimer
2011-05-07 9:28 ` Dmitry A. Kazakov
2011-05-07 9:57 ` Florian Weimer
2011-05-08 8:08 ` Dmitry A. Kazakov
2011-05-08 8:46 ` Florian Weimer
2011-05-08 9:32 ` Dmitry A. Kazakov
2011-05-08 10:30 ` Florian Weimer
2011-05-08 20:24 ` anon
2011-05-08 21:11 ` Simon Wright
2011-05-10 6:27 ` anon
2011-05-10 14:39 ` Adam Beneschan
2011-05-11 20:39 ` anon
2011-05-12 0:51 ` Randy Brukardt
2011-05-13 0:47 ` anon
2011-05-13 0:58 ` Adam Beneschan
2011-05-13 5:31 ` AdaMagica
2011-05-12 5:51 ` AdaMagica
2011-05-12 12:09 ` Robert A Duff
2011-05-12 14:40 ` Adam Beneschan
2011-05-14 0:30 ` Randy Brukardt
2011-05-09 7:48 ` Dmitry A. Kazakov
2011-05-09 20:41 ` Randy Brukardt
2011-05-14 23:47 ` anon
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