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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Ada 2012 Constraints (WRT an Ada IR)
Date: Thu, 15 Dec 2016 09:44:50 +0100
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Xref: news.eternal-september.org comp.lang.ada:32841
Date: 2016-12-15T09:44:50+01:00
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On 14/12/2016 23:53, Randy Brukardt wrote:
> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
> news:o2r1ca$184u$1@gioia.aioe.org...
> ...
>> Others tried to argue that such bodies are not bodies but magically
>> "preconditions". No, they are still bodies, just misplaced ones.
>
> Body /= implementation!! (Using "implementation" here in your sense as the
> entire execution of a subprogram.) A body is just the hidden part of the
> implementation; the part that is exposed to callers includes constraint,
> null exclusion, and predicate checks, and the precondition. The caller has a
> need to know about part of the implementation, and hopefully not about the
> rest. Exactly where the split between the specification and the body goes
> clearly depends on a need to know basis, and it has nothing to do with
> whether it is static or dynamic or provable.

This pretty good summarizes why I consider it such a bad idea.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de