[swift-evolution] [Pitch] Synthesized static enum property to iterate over cases

[Vladimir.S]

On 08.09.2017 12:56, Logan Shire via swift-evolution wrote:
> Googling ‘swift iterate over enum cases’ yields many results of various levels of hackery.
> Obviously it’s trivial to write a computed property that returns an enum’s cases as an
> array, but maintaining that is prone to error. If you add another case, you need to make sure
> you update the array property. For enums without associated types,
> I propose adding a synthesized static var, ‘cases', to the enum’s type. E.g.

Yes, this feature was discussed previously, but was not going into formal review for 
different reasons. Personally, I want this feature very much.
Currently, as I understand, if someone will implement this feature in Swift and 
raised a formal review - this addition can be accepted.
So, if someone is ready to implement this in Swift compiler code, we can discuss 
details(again) in this pitch to prepare a formal proposal.

Vladimir.

> 
> enum Suit: String {
>      case spades = "♠"
>      case hearts = "♥"
>      case diamonds = "♦"
>      case clubs = "♣"
> }
> 
> let values = (1…13).map { value in
>      switch value {
>      case 1: return “A”
>      case 11: return “J”
>      case 12: return “Q”
>      case 13: return “K”
>      default: return String(value)
>      }
> }
> 
> let cards = values.flatMap { value in Suit.cases.map { “\($0)\(value)"  } }
> 
> Yields [“♠A”, “ ♥ A”, …, “♣K”]
> Thoughts?
> 
> 
> Thanks!
> - Logan Shire
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