Function calls

[Pelle Månsson]

On 01/27/2010 08:34 AM, bearophile wrote:
> I have written the following closure, to generate numbers in 1-7 from numbers in 1-5, as alternative implementation of this:
> http://rosettacode.org/wiki/Seven-dice_from_Five-dice#D
>
> auto dice7Gen(alias d5)() {
>      int rem = 0;
>      int max = 1;
>
>      int gen7() {
>          while (rem / 7 == max / 7) {
>              while (max<  7) {
>                  int rand5 = d5() - 1;
>                  max *= 5;
>                  rem = 5 * rem + rand5;
>              }
>
>              int groups = max / 7;
>              if (rem>=  7 * groups) {
>                  rem -= 7 * groups;
>                  max -= 7 * groups;
>              }
>          }
>
>          int result = rem % 7;
>          rem /= 7;
>          max /= 7;
>          return result + 1;
>      }
>
>      return gen7;
> }
>
> Can you spot the bug? It returns an integer instead of a closure :-)
> The correct last line has to be:
>      return&gen7;
>
> But I think the real "bug" here is in the D2 design. In D2 calling callables without () has to be disallowed:
> -&  to take their reference/address
> - () to call them
> Otherwise syntax error at compile-time.
>
> Only properties marked with @property are allowed to be called without (). (If you really want it, then even free functions may be allowed to be marked with @property. This probably will not cause many bugs).
>
> This can avoid bugs and tidy the language a little more.
>
> Bye,
> bearophile

I disagree, I find the function calls without the () to be really 
prettifying.

But maybe that's just me.

I don't think that it causes serious bugs, you would see that it's an 
integer the moment you try and use it. It also helps changing code 
from/to functions.

I really like this feature, and would miss it should it go away.