Re: Min/Max attribute makes promises it can't keep

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

On Wed, 28 Apr 2010 04:47:42 -0700 (PDT), AdaMagica wrote:

>>> But the prefix of an attribute reference does not specify a
>>> constraint.
>>
>>> Integer'Min, Positive'Min, Natural'Min are all the same.
>>
>> But it should, at least in the case of Min/Max.
>> Integer'Min, Positive'Min, Natural'Min being all the same breaches the
>> spirit of the Ada language (what you see is what it means).
>> A topic for Ada 201z...
> 
> We could have had is thus and unconstrained Min as Positive'Base'Min
> when Min was introduced...
> 
> But it is as it is, and your proposal would be a severe
> incompatibility, so it won't fly.

Well, the proposal might be to fix rather the issue of the superfluous
subtype specification. Obviously Max (and many other attributes) are
primitive operations and need no subtype to specify. So:

    X'Succ, X'Pred, X'Image

Specifically max and min should be a dyadic operations:

   function "max" (Left, Right : T) return T'Base;

(and, please, no new reserved keywords!)

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