[swift-evolution] [Idea] Find alternatives to `switch self`

[Erica Sadun]

> On Mar 23, 2016, at 9:23 PM, Kevin Lundberg via swift-evolution <swift-evolution at swift.org> wrote:
> 
> This can be done today with no syntax changes (you'd have to return optional or handle the nil case though):
> 






>   var description: String? {
>     return [
>       .Hearts: "♥️",
>       .Spades: "♠️",
>       .Diamonds: "♦️",
>       .Clubs: "♣️"
>     ][self]
>   }

You could always use nil-coalescing

    return [
      .Hearts: "♥️",
      .Spades: "♠️",
      .Diamonds: "♦️",
      .Clubs: "♣️"
    ][self ] ?? "won't happen"

Or do something silly like this:

public extension Dictionary {
    public subscript(key: Key, fallback: Value) -> Value {
        return self[key] ?? fallback
    }
}

enum Suits {
    case Hearts, Spades, Diamonds, Clubs
    var description: String {
        let values: [Suits: String] =  [
            .Hearts: "♥️",
            .Spades: "♠️",
            .Diamonds: "♦️",
            .Clubs: "♣️"
            ]
        return values[self, "?"]
    }
}

Even thought they kind of sort of work, I don't like either one. 

-- E