on Wed Oct 12 2016, Hooman Mehr <swift-users-AT-swift.org> wrote:
>> On Oct 12, 2016, at 3:21 AM, Jean-Denis Muys via swift-users
>> <swift-users@swift.org> wrote:
>>
>>
>> But this is not very DRY.
>>
>> What would be a more idiomatic way?
>>
>
> The more idiomatic way is to look at API design in a new way. Note these
> points:
>
> 1. `Countable` variant is preferred when you want to deal with integer ranges
> as it more closely
> matches the element type.
> 2. Both countable range variants share a common protocol conformance already:
> `RandomAccessCollection`
> 3. Swift API design prefers member functions to free functions.
>
> Hence a more idiomatic (Swifty) API would probably be something like this:
>
> extension RandomAccessCollection {
>
> func random() -> Iterator.Element? {
>
> guard count > 0 else { return nil }
>
> let offset = arc4random_uniform(numericCast(count))
>
> let i = index(startIndex, offsetBy: numericCast(offset))
>
> return self[i]
> }
> }
>
> Using the above, both cases work and there is no repetition:
>
> (4..<10).random()
> (4...9).random()
>
>
> It also makes a lot more possible:
>
> let people = ["David", "Chris", "Joe", "Jordan", "Tony"]
> let winner = people.random()
Hey, that is pretty awesome!
--
-Dave
_______________________________________________
swift-users mailing list
swift-users@swift.org
https://lists.swift.org/mailman/listinfo/swift-users
