将枚举案例与参数进行比较答案

【问题标题】：Compare enum cases with parameters将枚举案例与参数进行比较
【发布时间】：2017-02-06 11:59:45
【问题描述】：

我正在使用 Swift 3 开发 iOS 应用程序，但遇到了一个问题。我有一个枚举：

enum MapMode: Equatable {
    case scenes
    case temperature
    case editingScene
    case editingWaterfall(waterfall: Waterfall, mode: PumpEditorMode, waterfallScene: WaterfallScene?)
    case editingWaterfallScenes(waterfall: Waterfall)
    case editingTemperature(thermostate: Thermostat)
    case editingShutter(shutter: Device, doorDirection: DoorDirection)
    case editingDoor
    case comfortScenesList

    public static func ==(lhs: MapMode, rhs: MapMode) -> Bool {
        switch (lhs, rhs) {
        case let (.editingTemperature(ther01), .editingTemperature(ther02)):
            return ther01.deviceId ?? 0 == ther02.deviceId ?? 0
        case let (a, b) where a.rawValue == b.rawValue:
            return true
        default:
            return false
        }
    }
}

我收到一个错误Value of type 'MapMode' has no member 'rawValue'，所以我意识到我需要为枚举添加原始值，所以我编辑了一个代码：

enum MapMode: Int, Equatable {
    case scenes = 0
    case temperature = 1
    case editingScene = 2
    case editingWaterfall(waterfall: Waterfall, mode: PumpEditorMode, waterfallScene: WaterfallScene?) = 3
    case editingWaterfallScenes(waterfall: Waterfall) = 4
    case editingTemperature(thermostate: Thermostat) = 5
    case editingShutter(shutter: Device, doorDirection: DoorDirection) = 6
    case editingDoor = 7
    case comfortScenesList = 8

    public static func ==(lhs: MapMode, rhs: MapMode) -> Bool {
        switch (lhs, rhs) {
        case let (.editingTemperature(ther01), .editingTemperature(ther02)):
            return ther01.deviceId ?? 0 == ther02.deviceId ?? 0
        case let (a, b) where a.rawValue == b.rawValue:
            return true
        default:
            return false
        }
    }
}

而且它也没有编译。 Enum with raw type cannot have cases with arguments 我的问题是：如何使带参数的枚举成为 Equatable？

编辑 1：临时（工作）解决方案

enum MapMode: Equatable {
    case scenes
    case temperature
    case editingScene
    case editingWaterfall(waterfall: Waterfall, mode: PumpEditorMode, waterfallScene: WaterfallScene?)
    case editingWaterfallScenes(waterfall: Waterfall)
    case editingTemperature(thermostate: Thermostat)
    case editingShutter(shutter: Device, doorDirection: DoorDirection)
    case editingDoor
    case comfortScenesList

    public static func ==(lhs: MapMode, rhs: MapMode) -> Bool {
        switch (lhs, rhs) {
        case (.scenes, .scenes), (.temperature, .temperature), (.editingScene, .editingScene), (.editingDoor, .editingDoor), (.comfortScenesList, .comfortScenesList):
            return true
        case let (.editingTemperature(ther01), .editingTemperature(ther02)):
            return ther01.deviceId ?? 0 == ther02.deviceId ?? 0
        case let (.editingWaterfall(waterfall01, _, _), .editingWaterfall(waterfall02, _, _)):
            return waterfall01.deviceId == waterfall02.deviceId
        case let (.editingWaterfallScenes(waterfall01), .editingWaterfallScenes(waterfall02)):
            return waterfall01.deviceId == waterfall02.deviceId
        case let (.editingShutter(shutter01, _), .editingShutter(shutter02, _)):
            return shutter01.deviceId == shutter02.deviceId
        default:
            return false
        }
    }
}

我决定中止rawValues 并扩展== 函数。这个解决方案有一个效果。每当我添加新的case 时，我需要记住扩展== 功能。

我正在寻找更通用的解决方案。

【问题讨论】：

你可以只指定第一个值（= 0），每个连续的值都会递增
@Ashley Mills 不工作它会生成错误消息Enum with raw type cannot have cases with arguments

标签： ios swift enums swift3

【解决方案1】：

您可能希望将它们分成两个枚举：

enum MapMode: Equatable {
    case mapMode(mode:ModeType)
    case editingWaterfall(waterfall: Waterfall, mode: PumpEditorMode, waterfallScene: WaterfallScene?)
    case editingWaterfallScenes(waterfall: Waterfall)
    case editingTemperature(thermostate: Thermostat)
    case editingShutter(shutter: Device, doorDirection: DoorDirection)

    public static func ==(lhs: MapMode, rhs: MapMode) -> Bool {
        switch (lhs, rhs) {
        case let (.editingTemperature(ther01), .editingTemperature(ther02)):
            return ther01.deviceId ?? 0 == ther02.deviceId ?? 0
        case let (mapMode(a), mapMode(b)) where a.rawValue == b.rawValue:
            return true
        default:
            return false
        }
    } 
}

enum ModeType: Int, Equatable {
    case scenes = 0
    case temperature
    case editingScene
    case editingWaterfall
    case editingWaterfallScenes
    case editingTemperature
    case editingShutter
    case editingDoor
    case comfortScenesList

    public static func ==(lhs: ModeType, rhs: ModeType) -> Bool {
        switch (lhs, rhs) {
        case let (a, b) where a.rawValue == b.rawValue:
            return true
        default:
            return false
        }
    } 
}

【讨论】：