[swift-evolution] For-loop revisited

[David Waite]

> On Feb 26, 2016, at 9:07 AM, Ted F.A. van Gaalen via swift-evolution <swift-evolution at swift.org> wrote:
> 
> >>  Does .stride(), which in the end uses a descendant of SequenceType, just calculate a new value each time   for..in..   uses .next() on this collection? 

this.

>     for  x from xmin to xmax by xstep  { }
> 
>     for x from xmax to xmin by -xstep  { } 
> 
>     for apple from 1 to applesInTruck  { }
> 
> No need for collections in these cases,

As the thread for removal of C-style for showed in benchmarks, using a range or stride does not have a performance impact under optimization. Such new syntax would need to stand on its own as a second alternative to using ranges/strides. 

Considering that it would require reserving three new keywords (‘from’, ‘to’, and ‘by’) this will be a hard argument to make.

-DW

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