[swift-evolution] [Discussion] stride behavior and a little bit of a call-back to digital numbers

[Curt Clifton]

Cheers,

Curt

> On Feb 27, 2016, at 10:03 PM, Erica Sadun via swift-evolution <swift-evolution at swift.org> wrote:
> 
> I've updated the proposal to take this into account: https://gist.github.com/erica/03c398c06f6c47824429
> 
> It makes two core recommendations:
> 
> 1. Adjust stride function semantics to expand from two to three functions, renaming them appropriately.
> 2. Break floating point strides away from Strideable to provide their own stride method implementations.

I don't have a strong opinion on the proposal. These sorts of strides are rare in the problem domains I work in. I would like to nitpick the proposed documentation for the new stride(through:,by:). The revised proposal gives the new documentation as:

A Strideable through sequence currently returns the sequence of values (self, self + stride, self + stride + stride, ... last) where last is the last value in the progression greater than or equal to end. There is no guarantee that end is an element of the sequence.


That should read “where last is the **first** value in the progression that is greater than or  equal to end.“ As proposed, last would be the largest number representable in self’s type that is a multiple of stride greater than self. That’s not the intent.

Cheers, 

Curt

-------------------------
Curt Clifton, PhD 
Software Developer 
The Omni Group 
www.curtclifton.net 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160228/a1e09703/attachment.html>