Why not allow empty code blocks?

[Marko Rauhamaa]

"D'Arcy J.M. Cain" <darcy at Vex.Net>:

> On Sat, 23 Jul 2016 14:13:46 +0300
> Marko Rauhamaa <marko at pacujo.net> wrote:
>> I don't see an ambiguity: obviously the print call takes place after
>> finishing the loop.
>
> It's ambiguous to the reader what was actually meant.  Forcing a "pass"
> there shows the reader that the empty block was not a mistake.

Just let the syntax speak for itself. The code means what the language
definition says it means.

>> I wonder if there is any true case of ambiguity. I guess this is all
>> about an enforced aesthetic principle: GvR doesn't like the looks of
>> an empty block.
>
> I don't think that he would be alone.

Then just appeal to that subjective preference instead of some objective
necessity.

BTW, the standard shell requires a dummy statement in a block even
though the block boundaries are clearly marked:

   while not quit; do
   done

is a syntax error. This works:

   while not quit; do
       :
   done

> If you allow empty blocks and you use it I hope that you would add a
> comment so that the reader knows that you meant it.

Once you learn the idioms of a language, you don't need to comment the
obvious.

> for x in sequence: # this is an empty block
>
> Is that better than "pass"?

Er, in that hypothetical world, the right answer would be simply:

   for x in sequence:


Note that I'm not arguing for the removal of "pass." I'm just saying
it isn't strictly necessary.


Marko