原型模式-Swift

Prototype

原型模式是通过现有对象的所有属性来复制自身，创建一个新的对象。当类的实例间差异仅是属性值的不同时，这种做法将比手工实例化更加方便。

Prototype.png

Example

protocol ProtoType {
    func clone() -> Self;
}

class ConcretePrototype: ProtoType {

    var value: Float?
    let currency: String
    
    
    required init(currency: String) {
        self.currency = currency
    }
    
    internal func clone() -> Self{
        return type(of: self).init(currency: self.currency)
    }

}

Usage

let prototype = ConcretePrototype(currency: "RMB")

let RMB50 = prototype.clone()
RMB50.value = 50
let RMB100 = prototype.clone()
RMB100.value = 100