自定义类型的Swift枚举符合哈希协议
我有这样一个枚举:自定义类型的Swift枚举符合哈希协议,swift,swift2,Swift,Swift2,我有这样一个枚举: enum Animals { case Cow (MyCowClass) case Bird (MyBirdClass) case Pig (MyPigClass) case Chicken (MyChickenClass) } 每种类型都符合哈希协议。然后,此枚举将成为另一个类的属性: class Farm { let name = "Bob's Farm" var animal = Animals
enum Animals {
case Cow (MyCowClass)
case Bird (MyBirdClass)
case Pig (MyPigClass)
case Chicken (MyChickenClass)
}
每种类型都符合哈希协议。然后,此枚举将成为另一个类的属性:
class Farm {
let name = "Bob's Farm"
var animal = Animals
required init(animal: Animals) {
self.animal = animal
}
我想从案例的实例中获取散列值,并将其用于枚举,以便使用name&animal使Farm类可散列 您可以使动物可散列,例如:
enum Animals : Hashable {
case Cow (MyCowClass)
case Bird (MyBirdClass)
case Pig (MyPigClass)
case Chicken (MyChickenClass)
var hashValue: Int {
switch self {
case .Cow(let v): return v.hashValue
case .Bird(let v): return v.hashValue
case .Pig(let v): return v.hashValue
case .Chicken(let v): return v.hashValue
}
}
}
func ==(lhs: Animals, rhs: Animals) -> Bool {
return ...
}
类农场
,例如:
class Farm : Hashable {
var hashValue: Int {
return [name.hashValue, animal.hashValue].hashValue
}
}
func ==(lhs: Farm, rhs: Farm) -> Bool {
return ...
}
最后,int的容器实现一个属性hashValue
extension CollectionType where Generator.Element: Int {
var hashValue: Int {
return ...
}
}
对于适当的算法,您可以在web上搜索-例如:假设您不希望基于关联对象的枚举,则接受答案的替代方法如下所示:
private enum AnimalType: Int {
case Cow = 0
case Bird = 1
case Pig = 2
case Chicken = 3
}
func == (lhs: Animals, rhs: Animals) -> Bool {
return lhs.hashValue == rhs.hashValue
}
enum Animals: Hashable {
case Cow (MyCowClass)
case Bird (MyBirdClass)
case Pig (MyPigClass)
case Chicken (MyChickenClass)
var hashValue: Int {
get {
switch self {
case .Cow(_):
return AnimalType.Cow.hashValue
}
}
}
}
啊,我知道你在那里做了什么。谢谢你的选择。