Swift enums should be iterable using for-in loops

Originator:tim.sheridan
Number:rdar://17174768 Date Originated:20140605
Status:Duplicate/17102392 Resolved:20140611
Product:Swift Product Version:
Classification:New feature Reproducible:Always
 
One of my most common things that I do with enums is to iterate through each possible member of the enum. GuidedTour.playground even makes you do such a task to generate a deck of cards.

But, Swift doesn't have a good support to do this. The following is rejected as an error ('Suit.Type' does not conform to protocol 'Sequence'), but I propose that it should work for this purpose:

enum Suit {
    case Spades, Hearts, Diamonds, Clubs
}

for suit in Suit {
    if suit == Suit.Spades {
        println("ding")
    }
}

Comments

duplicated in 17262589

well said

By seanwolter at June 11, 2014, 2:02 a.m. (reply...)

In Haskell there is an Enumerable typeclass that can be derived for this purpose. Seems like a perfect use case for a Protocol, although it doesn't appear that Swift has such a built-in protocol or any way to automatically derive any Protocol implementation.

By bob at June 5, 2014, 11 p.m. (reply...)

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