第二十章 嵌套类型

struct BlackjackCard {

   // 嵌套的 Suit 枚举

    enum Suit: Character {

        case Spades = "♠", Hearts = "♡", Diamonds = "♢", Clubs = "♣"

    }

    // 嵌套的 Rank 枚举

    enum Rank: Int {

         case Two = 2, Three, Four, Five, Six, Seven, Eight, Nine, Ten

        case Jack, Queen, King, Ace

        struct Values {

             let first: Int, second: Int?

         }

        var values: Values {

            switch self {

            case .Ace:

                return Values(first: 1, second: 11)

            case .Jack, .Queen, .King:

                return Values(first: 10, second: nil)

             default:

                return Values(first: self.rawValue, second: nil)

              }

        }

    }

    // BlackjackCard 的属性和方法

    let rank: Rank, suit: Suit

    var description: String {

        var output = "suit is \(suit.rawValue),"

        output += " value is \(rank.values.first)"

        if let second = rank.values.second {

           output += " or \(second)"

        }

        return output

    }

}

let theAceOfSpades = BlackjackCard(rank: .Ace, suit: .Spades)

print("the ace of spades: \(theAceOfSpades.description)")

let theQueenOfClubs = BlackjackCard(rank: .Queen, suit: .Clubs)

print("the queen of clubs: \(theQueenOfClubs.description)")

let heartsSymbol = BlackjackCard.Suit.Hearts.rawValue

print(BlackjackCard.Rank.init(rawValue: 14)?.values)