Re: Overloading attributes

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

anon wrote on comp.lang.ada:
> Before I get to what "Randy Brukardt" an ARG member said, let me
> give you a little language lesson:

You should not try to teach the Ada language to Jean-Pierre, who is
also an ARG member.

> If a programmer write a program using Ada programmer is author of that
> Implementation aka program. If a programmer write a system (multiple Ada
> programs), the programmer is the author of that Implementation or System.
> And as the Implementation the Standard allows the author to create her/his
> own attributes for that Implementation.

Little language lesson for you: as Peter wrote, the "implementation"
is
the compiler and run-time library, not the "program".  In fact the
"implementation" is not necessarily written in Ada.

> From previous posts by "Randy Brukardt" <ra...@rrsoftware.com>
>                       Oct 28, 2009
>
> Post 1:
>
>> First, a historical question: Was there a proposal for user attributes
>> that was considered for Ada 2005?
>
> Not seriously. It had been rejected for Ada 95, and in general, we didn't
> want to rehash that old ground.
>
> Post 2:
>
>> When it was proposed for Ada 95, I griped about the implementation cost (as
>> noted in my original message). Some other implementers agreed with me. When
>> the scope reduction was applied to the Ada 9x proposal (the original
>> language was just too large for the time, no one would ever have implemented
>> it), things that were just "nice to haves" were removed (even if they were
>> technically sound). This was in that category, so out it went. Same thing
>> happened to conditional expressions and many other useful ideas.
>> The reasoning hasn't changed, so I don't think we'll be revisiting that any
>> time soon.
>
> Really!!!
>
> Now, what Randy forgot was that "conditional expressions" have been added
> to GNAT starting in Ada 2005 and extended in Ada 2012. So, ARG does rehash
> that old ground.

Another little language lesson: GNAT is not Ada.  Randy was talking
about
the Ada language definition, i.e. the ISO standard, i.e. the ARM.  You
are
talking about one particular implementation called GNAT, which Randy
does not
work on (in fact he works on another implementation of Ada).

And conditional expressions are not attributes.

> So, people are looking for "user defined attribute" to be reintroduce
> and added to Ada 2012 since it has not been formally voted on as a
> Standard yet (which will occur between 2012 and 2020). And if not added
> will be strongly requested from the Ada community for Ada 2020 Standard.

There are no user-defined attributes.  There are implementation-
defined
attributes.  Some nut not all attributes (some standard, some
implementation-defined) allow attribute definition clauses.  Sad but
true.

> And others "nice to have" features that were once remove from the Ada 95
> Standard, will be requested or added back in Ada 2020.  Because it is
> Time, some may say

That's off-topic but for the sake of your credibility, could you name
one such "nice to have" feature that has been removed from the Ada 95
Standard? (i.e. one that was present in Ada 83 but absent in Ada 95)

> J-P. Rosen writes:
>> Please stop spreading FUD.

+1

--
Ludovic Brenta.