> On Apr 9, 2016, at 4:33 AM, Haravikk via swift-evolution
> <swift-evolution@swift.org> wrote:
>
> While I’m in favour of the basic idea I think the operator selection is too
> complex, and I’m not sure about the need for negative strides. Really all I
> want are the following:
>
> (0 ... 6).striding(by: 2) // [0, 2, 4, 6] x from 0 to 6
> (0 ..< 6).striding(by: 2) // [0, 2, 4] x from 0 while
> <6
> (6 ... 0).striding(by: 2) // [6, 4, 2, 0] x from 6 to 0
> (6 ..> 0).striding(by: 2) // [6, 4, 2] x from 6 while
> >0
>
> Everything else should be coverable either by flipping the order, or using
> .reverse(). The main advantage is that there’s only one new operator to
> clarify the 6 ..> 0 case, though you could always just reuse the existing
> operator if you just interpret it as “x from 6 to, but not including, 0"
`.reverse()` returns an array, though, not a StrideTo<>, which means it’ll get
in an infinite loop on infinite sequences. This works fine:
for i in stride(from: 0.0, to: Double.infinity, by: M_PI) {
if someTestInvolving(i) { break }
...
}
But this never even starts executing the loop because of the infinite loop
inside `.reverse()`:
for i in stride(from: -Double.infinity, to: 0.0, by: M_PI).reverse() {
if someTestInvolving(i) { break }
...
}
- Dave Sweeris_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution
