Would `sequence(mutatingState:next:)` perhaps be clearer?
> On 20 May 2016, at 10:37 AM, Trent Nadeau via swift-evolution > <[email protected]> wrote: > > Ah, yes. I apologize. The fact that state is inout, and the same instance is > always passed in confused me. Thanks for the correction. > > On Thu, May 19, 2016 at 7:46 PM, Brent Royal-Gordon <[email protected] > <mailto:[email protected]>> wrote: > > Also note that there's a typo in the second example: > > > > for view in sequence(initial: someView, next: { $0. > > superview }) { > > > > // someView, someView.superview, someView.superview.superview, ... > > > > } > > > > > > should be: > > > > for view in sequence(state: someView, next: { $0. > > superview }) { > > > > // someView, someView.superview, someView.superview.superview, ... > > > > } > > I don't think these are mistakes—in each iteration of the loop, $0 is > supposed to be the view from the previous iteration. > > If you wanted an example using `state`, here's one which is roughly > equivalent to `stride(from: 1.0, to: 2.0, by: 0.1)`, using a > non-error-accumulating algorithm: > > let start = 1.0 > let end = 2.0 > let distance = 0.1 > > for color in sequence(state: -1.0, next: { $0 += 1; let next = start > + $0 * distance; return next < end ? next : nil }) { > … > } > > -- > Brent Royal-Gordon > Architechies > > > > > -- > Trent Nadeau > _______________________________________________ > swift-evolution mailing list > [email protected] <mailto:[email protected]> > https://lists.swift.org/mailman/listinfo/swift-evolution > <https://lists.swift.org/mailman/listinfo/swift-evolution>
_______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
