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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: Generic-Package Elaboration Question / Possible GNAT Bug.
Date: Thu, 24 Nov 2011 08:07:45 +0000
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Date: 2011-11-24T08:07:45+00:00
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"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:

> On Wed, 23 Nov 2011 15:12:07 +0000, Simon Wright wrote:
>
>> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
>> 
>>> P.S. I hope everybody agrees that dynamic pre-/post-conditions are a
>>> part of the implementation?
>> 
>> I think I don't actually care that much!
>
> Should it mean that you don't care about separation of implementation
> and interface?

What I think I was trying to say was that it doesn't seem to me to make
a lot of difference whether the pre/post-conditions are
dynamic. Providing, of course, I've understood your point.

To take Georg's example of the stack, I don't see how you're going to
express the fact that its capacity is bounded other than by comments
about constraint errors or by preconditions.

I seem to be tempted into speculations about SPARK at this point. Stacks
seem to be a rather dangerous construct from the point of view of
proving correctness, logic not being very good at counting.