Re: Gnat 2013 is out!

[Georg Bauhaus <rm.dash-bauhaus@futureapps.de>]

On 11.06.13 04:39, Randy Brukardt wrote:
> "Adam Beneschan" <adam@irvine.com> wrote in message
> news:33025e6c-b893-4c66-98f6-0fb469016583@googlegroups.com...
>> On Saturday, June 1, 2013 4:51:01 AM UTC-7, Georg Bauhaus wrote:
>>> On 01.06.13 00:07, Randy Brukardt wrote:
>>>
>>>> Unless the syntax makes it pretty obvious that this is a dummy,
>>>> discarded
>>>> parameter, this idea is going nowhere. (And it might very well go
>>>> nowhere
>>>> even if the syntax is perfect.)
>>>
>>> Can you perhaps employ the new subpools mechanism? To provide
>>> constraints for an anonymous, "boxed object", we'd write
>>>
>>>      My_Proc (Obj1, Obj2, Result => <> String'(1..80 => <>));
>>>
>>> Then, if __ stands for a subpool known only to the compiler
>>> such as, ahem, the stack, the expansion is the impossible
>>>
>>>      My_Proc (Obj1, Obj2, Result => (new(__) String'(1..80 => <>)).all);
>>
>> I'm beginning to regret opening this subject up.
>
> I feel your pain, after I encouraged it. What part of "really simple" don't
> people understand?

Two parts (and please note that the subpools are inessential):

First, "really simple" is always a little suspicious when the
author of a compiler emphasizes simplicity. ;-) ;-) ;-)

Second, concerning the constraints that need to be supplied,
is there *any* way in Ada that allows them to be stated
"really simply"?

If the dummy syntax is for expressions of substitutes of a regular
declaration, how can a dummy expression be so much more simple
than a dummy declaration?

About the only thing I can imagine towards simplified syntax
is inference of type *and* range constraints, with the help
of context (the subprograms' declarations). Is that double
inference part of Ada right now?

If not, the closest level of syntactic simplicity would be that
of aggregates, with constraints, wouldn't it?