在Swift中使用泛型实现装饰器模式

// 1. 定义一个基础组件接口
protocol Component {
    func operation() -> String
}

// 2. 创建具体组件
class ConcreteComponent: Component {
    func operation() -> String {
        return "ConcreteComponent"
    }
}

// 3. 创建装饰者基类
class Decorator: Component {
    private let component: Component
    
    init(_ component: Component) {
        self.component = component
    }
    
    func operation() -> String {
        return component.operation()
    }
}

// 4. 创建具体装饰者
class ConcreteDecoratorA: Decorator {
    override func operation() -> String {
        return "ConcreteDecoratorA(\(super.operation()))"
    }
}

class ConcreteDecoratorB: Decorator {
    override func operation() -> String {
        return "ConcreteDecoratorB(\(super.operation()))"
    }
}

// 使用示例
let component = ConcreteComponent()
let decoratorA = ConcreteDecoratorA(component)
let decoratorB = ConcreteDecoratorB(decoratorA)

print(decoratorB.operation()) // 输出: ConcreteDecoratorB(ConcreteDecoratorA(ConcreteComponent))