Types Swift:枚举依赖于另一个枚举

我正在制作一个简单的游戏来更好地了解新语言，我制作了描述游戏级别的枚举。我想做另一个枚举，描述每个级别上的敌人。（级别有不同的敌人）。所以，我想归档如下内容：

enum GameLevel : Int {

    case Forest = 0, Swamp, Castle
    ...
}

enum Enemies : Int {

   // if .Forest than
   case Stump = 0, Frog // Forest Enemies

   //esle if ...
   case Zombie = 0, Witch // Swamp Enemies
   case Knight = 0, Archer // Castle Enemies 


   //var ... some predefined properties that all enemies have but each enemy have it's own values  
}

enum GameLevel : Int {
    case Forest, Swamp, Castle
}

enum Enemies : Int {

    case Stump
    case Frog
    case Zombie
    case Witch
    case Knight
    case Archer

    static func enemiesInLevel(level: GameLevel) -> [Enemies] {
        switch level {
        case .Forest:
            return [Stump, Frog]
        case .Castle:
            return [Knight, Archer]
        default:
            return []
        }
    }

}

// this is how you can call it
let forestEnemies = Enemies.enemiesInLevel(.Forest)
let castleEnemies = Enemies.enemiesInLevel(.Castle)

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enum有错误的语法，但我正在寻找一种方法来制作类似的东西。归档此文件的最佳解决方案是什么

您可以编写一个函数，返回给定级别中的所有敌人，如下所示：

enum GameLevel : Int {

    case Forest = 0, Swamp, Castle
    ...
}

enum Enemies : Int {

   // if .Forest than
   case Stump = 0, Frog // Forest Enemies

   //esle if ...
   case Zombie = 0, Witch // Swamp Enemies
   case Knight = 0, Archer // Castle Enemies 


   //var ... some predefined properties that all enemies have but each enemy have it's own values  
}

enum GameLevel : Int {
    case Forest, Swamp, Castle
}

enum Enemies : Int {

    case Stump
    case Frog
    case Zombie
    case Witch
    case Knight
    case Archer

    static func enemiesInLevel(level: GameLevel) -> [Enemies] {
        switch level {
        case .Forest:
            return [Stump, Frog]
        case .Castle:
            return [Knight, Archer]
        default:
            return []
        }
    }

}

// this is how you can call it
let forestEnemies = Enemies.enemiesInLevel(.Forest)
let castleEnemies = Enemies.enemiesInLevel(.Castle)

---

您可以向GameLevel添加实例方法，以列出与GameLevel特定元素相关的所有敌人

enum GameLevel : Int {
    case Forest = 0, Swamp, Castle
    func enemies() -> Array<Enemy> {
        switch self {
        case .Forest: return [.Stump, .Frog]
        case .Swamp: return [.Zombie, .Witch]
        case .Castle: return [.Knight, .Archer]
    }
}

enum Enemy : Int {
    case Stump = 0, Frog, Zombie, Witch, Knight, Archer
}

let forestLevel = GameLevel.Forest
forestLevel.enemies()

摘自：苹果公司《Swift编程语言》。iBooks

---

提示：您可以在

enum

@pNre中定义函数，我知道，但我不明白这对我有什么帮助。