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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Strings with discriminated records
Date: Tue, 29 May 2018 12:14:26 +0200
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Xref: reader02.eternal-september.org comp.lang.ada:52760
Date: 2018-05-29T12:14:26+02:00
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On 2018-05-29 11:31 AM, AdaMagica wrote:
> Am Dienstag, 29. Mai 2018 09:49:20 UTC+2 schrieb Dmitry A. Kazakov:
>> Yes. Renaming temporary objects is probably a language design bug.
> 
> It was a consequence of making function results to objects. Before, they were mere values.
> Objects can be renamed.

Yes, but renaming objects without names is obviously charged with 
potential problems. It is best to leave anonymous objects alone for 
optimization reasons.

>> renaming is broken in so many ways that one more, one less does not make
>> much difference.
> 
> Hm, I only see one lie with renaming:
> 
> X: constant Integer := -1;
> Y: Positive renames X;
> 
> What are the other broken features?
1. Not sliding array indices even if explicitly required/implied/expected.

(This is possibly a similar problem to with Integer/Positive that 
constraints are not respected/checked/enforced/rejected.)

2. Renaming can hide/conflict with the original object and its 
renamings. This should never happen.

3. There should be no subtype specification in renaming at all. Renaming 
must deal with names only.

(I understand the motivation behind. I.e. to be able to rename 
overloaded subprograms. But that is a false place to solve an unrelated 
problem: lack unambiguous naming for subprograms)

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