Re: Disallowing Pre-Defined Operations

[Robert Dewar <robert_dewar@my-deja.com>]

In article <38ED3145.BE3CEC68@quadruscorp.com>,
  "Marin D. Condic" <mcondic-nospam@quadruscorp.com> wrote:
> If its too hard to implement or you just don't think it has
> enough interest for ACT to support it

You missed my main point, which is that in the unlikely event
that a compiler DOES want to support this efficiently, no
change to the language is required, since Intrinsic can be
used for this purpose.

> The original question was basically "What new features would
> it benefit Ada to have?"

The fact that your compiler handled the user defined version
inefficiently may say nothing more than that you were using
an inefficient compiler, at least with respect to this
particular issue. There is no guarantee that building a
feature into the language means it will be done more
efficiently on a given compiler.

Indeed the only convincing input here from my point of view
would be some user who programs it themselves, and actually
measures that there is a performance problem.

And if such a situation arose, as I mention above, no language
change is necessary, one would simply improve the efficiency
of the feature (I am quite unconvinced that Intrinsic would
be required, since this seems something that can be programmed
perfectly efficiently in Ada, but Intrinsic is there if needed).

I actually find that very few Ada programmers properly
understand the intrinsic feature of Ada 95, or even know
of its existence. Pity -- because this is really an important
part of the language design.



 I don't know about the rest of the world but if Ada had
> saturated math data types *I* would have beaten it to death in
the
> engine control business. I'd suspect that other embedded
programmers
> would find the feature *very* useful and (here's the good
part!) it
> doesn't exist (that I am aware of) in the more popular
languages for
> that market sector. (Product distinction?)
>
> It doesn't sound to me like something that would require some
massive
> compiler rewrite or some fundamental change in Ada syntax or
semantics.
> I'm no expert, but it seems fairly small and self-contained
such that a
> compiler could provide it as an option that could be toggled
by
> switches. Syntax? Maybe "type T is saturated digits 6 ;" or
"type T is
> saturated range -128..127 ;" Maybe as a pragma? "pragma
Saturate (T) ;"
> I personally wouldn't be fussy. :-)
>
> MDC
> --
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>
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