Re: Studying and Maintaining GNAT, Is There Any Interest in a New Group?

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On 2018-09-01 21:42, Robert A Duff wrote:
> "Randy Brukardt" <randy@rrsoftware.com> writes:
> 
>> Note that every one of these renames was illegal in Ada 83. Someone thought
>> that it was important to allow Ren1 in Ada 95, and that led to all of these
>> bizarre cases.
> 
> I think it was mostly accidental. We needed to say that the result of
> a function call is an object (as opposed to a value, as in Ada 83),
> because it needs to get finalized. This caused renaming of
> function calls to become legal, which we viewed as harmless
> and sometimes useful.

I think distinction object vs. value is a wrong. Renaming should apply 
to named entities, e.g. *named* objects. Renaming anonymous things makes 
no sense, IMO.

> We didn't take the further step of making all the other cases
> you mentioned legal. Perhaps we should have, just for uniformity.

Uniformly counterintuitive. If an expression to be named, that 
intuitively should have semantics of a call. E.g.

    Line : String renames Get_Line (File);
begin
    loop
       Put_Line (Line); -- Dumping all the file
    end loop;
exception
    when End_Error => -- From Put_Line, not from declaration!
       null;

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