Re: A few questions

[Simon Wright <simon@pushface.org>]

Simon Wright <simon@pushface.org> writes:

> "Randy Brukardt" <randy@rrsoftware.com> writes:
>
>> "Simon Wright" <simon@pushface.org> wrote in message 
>> news:ly611kmh1g.fsf@pushface.org...
>> ...
>>> I wrote the attached, using generalized iteration, which bears a
>>> strong resemblance to the standard container iteration (the names
>>> bear too strong a resemblance! but this way you can see the
>>> commonality).
>>
>> I suspect you could have written this in a lot simpler
>> fashion. Something similar to the Prime_Numbers iterator found in the
>> ACATS foundation (F552A00, look in the support subdirectory,
>> specifically
>> http://www.ada-auth.org/cgi-bin/cvsweb.cgi/acats/support/f552a00.a)
>> would be a starting point. (Thanks again to Brad Moore for creating
>> this foundation and the associated ACATS tests to give all Ada
>> implementers something to use as a correct example of iterators.)
>
> Great pointer. Though I think the Date case would be a bit more
> complicated, because you couldn't constrain a Date_Set by Times or
> Durations.

And I was hoping to write

   with Ada.Text_IO;
   with F552A00_Prime_Numbers;
   procedure Primes is
   begin
      for P of F552A00_Prime_Numbers.Prime_Number_Set'(Max_Value => 31) loop
         Ada.Text_IO.Put_Line (P'Img);
      end loop;
   end Primes;

but (surprise)

   primes.adb:5:08: cannot iterate over "Prime_Number_Set"