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Created June 4, 2014 05:03
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Possible Solution for Swift Enum conforming to a protocol
enum testEnum: ExampleProtocol{
case a, b, c
var simpleDescription: String{
get{
return "an example enum"
}
set {
simpleDescription = newValue
}
}
mutating func adjust() {
simpleDescription += " (whatever)"
}
}
var protoEnum = testEnum.a
let test = protoEnum.simpleDescription
@kasei
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kasei commented Jun 4, 2014

Or, as a self-contained enumeration using associated values:

enum testEnum: ExampleProtocol{
    case a(String)
    case b(String)
    var simpleDescription: String {
        get{
            switch self {
            case a(let v):
                return "a: \(v)"
            case b(let v):
                return "b: \(v)"
            }
        }
        set {
            switch self {
            case a(let v):
                self = a(newValue)
            case b(let v):
                self = b(newValue)
            }
        }
    }
    mutating func adjust() {
        switch self {
        case a(let v):
            self = a(v + " (mutated)")
        case b(let v):
            self = b(v + " (mutated)")
        }
    }
}

var protoEnum = testEnum.b("test enum")
protoEnum.adjust()
println(protoEnum.simpleDescription)
# prints: b: test enum (mutated)

@MrSpockDe
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I am not exacly sure, how a conforming enum would look like.
I tried:

enum SimpleEnum: String {
        case simpleDescription = "A simple enum type."
        func adjust() ->String {
            return self.toRaw() + " - finally adjusted"
        }
    }

    var myEnum = SimpleEnum.simpleDescription
    let descr = myEnum.adjust()

because my understanding from reading the book was, that you only can use the expression after the collon as associated value. But probaby my solution is not conform to the protocol

@tempelmann
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Here's how I solved it based on kasei's code:

enum ServerResponse: ExampleProtocol {
    case Result(String, String)
    case Error(String)
    var simpleDescription: String {
        get {
            switch self {
            case let .Result(sunrise, sunset):
                return "Sunrise is at \(sunrise) and sunset is at \(sunset)."
            case let .Error(error):
                return "Failure...  \(error)"
            }
        }
    }
    mutating func adjust() {
        switch self {
            case Result(let v1, let v2):
                self = Result(v1 + " (adjusted)", v2 + " (adjusted)")
            case Error(let v1):
                self = Error(v1 + " (adjusted)")
        }
    }
}

var success = ServerResponse.Result("6:00 am", "8:09 pm")
var failure = ServerResponse.Error("Out of cheese.")
success.adjust()
failure.adjust()
print(success.simpleDescription)
print(failure.simpleDescription)

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