foreach

[Manu via Digitalmars-d]

On 13 June 2014 19:15, Jonathan M Davis via Digitalmars-d
<digitalmars-d at puremagic.com> wrote:
> On Fri, 13 Jun 2014 01:00:11 +1000
> Manu via Digitalmars-d <digitalmars-d at puremagic.com> wrote:
>
>> I often find myself wanting to write this:
>>   foreach(; 0..n) {}
>> In the case that I just want to do something n times and I don't
>> actually care about the loop counter, but this doesn't compile.
>>
>> You can do this:
>>   for(;;) {}
>>
>> If 'for' lets you omit any of the loop terms, surely it makes sense
>> that foreach would allow you to omit the first term as well?
>> I see no need to declare a superfluous loop counter when it is unused.
>
> I'd honestly rather see for(;;) {} removed than have foreach(; 0..n) {} added.
> I don't like special cases like like these.
>
> And I really don't think that it's a big deal to have to provide a counter
> variable that you're not going to explicitly use. I can see why you'd want to
> be able to skip providing the variable, but all it's saving you is typing one
> character, which doesn't at all seem worth it to me.
>
> And if the argument is that the compiler could potentially make optimizations
> based on the lack of a variable, I would argue that the compiler should be
> able to make those same optimizations based on the fact that the variable is
> unused beyond being iterated over.

If front() is not pure, it can't be eliminated.


> So, while I can see why you might like this, it seems like an awfully small
> thing for you to try and claim it's a big improvement.

I didn't claim it's a big improvement. It just bugs me, and has done
on numerous occasions.