[swift-evolution] Feature proposal: Range operator with step

[Dave Abrahams]

on Mon Mar 28 2016, Erica Sadun <swift-evolution at swift.org> wrote:

>> On Mar 28, 2016, at 3:54 PM, Dave Abrahams via swift-evolution <swift-evolution at swift.org> wrote:
>> 
>> 
>> on Mon Mar 28 2016, Erica Sadun <swift-evolution at swift.org> wrote:
>> 
>
>>>> On Mar 28, 2016, at 3:25 PM, Dave Abrahams via swift-evolution
>>>> <swift-evolution at swift.org> wrote:
>>>> 
>>>> 
>>>> on Mon Mar 28 2016, Xiaodi Wu
>>> 
>>>> <swift-evolution at swift.org
>>>> <mailto:swift-evolution at swift.org>>
>>>> wrote:
>>>> 
>>>>> Right, Countable could refine Strideable. I'm no expert on this, but
>>>>> some cursory reading suggests that the analogous feature in C++ simply
>>>>> requires the type to have operator++ defined. Obviously, that won't
>>>>> work for Swift 3.0...
>>>> 
>>>> Hmm, instead of defining a new protocol (Countable), what if we just use
>>>> “Strideable where Stride : Integer” as a constraint?
>>> 
>>> I like a differentiation between continuous and discrete things
>>> although both can have ranges, membership, fences,
>>> and a way to stride through them
>> 
>> Strideable where Stride : Integer expresses just exactly that.  Now if I
>> could only get the type-checker to cooperate...
>
> I am ridiculously excited about what you're doing there. 
> Looking forward to beautiful floating point strides if for no
> other reason than I can point out how well they work for math
> in comparison to traditional for;;loops, so maybe people will
> stop burning semicolons on my lawn.

The basics:
https://github.com/apple/swift/commit/a5c3c63c3d5d940f729c23aab342ea4d270d264a

-- 
Dave