如何使用Swift对象方法作为闭包？ [英] How to use an Swift object method as a closure?

问题描述

我想使用对象方法作为闭包，因为我需要在对象的不同位置多次重复使用相同的闭包。让我们假设我有以下：

I'd like to use an object method as a closure because I need to reuse the same closure multiple times in different places in an object. Let's say I have the following:

class A {
    func launch(code: Int) -> Bool { return false }
}

我需要一个类型 Int - > Bool 。我如何能够使用 launch 方法作为闭包？我宁愿不做像 {self.launch（$ 0）} 如果我可以直接引用的方法。

And I need a closure that is of type Int -> Bool in the same object. How would I be able to use the launch method as the closure? I'd rather not do something like { self.launch($0) } if I can just directly reference the method.

推荐答案

实例方法是curried函数，它将实例
作为第一个参数。因此

Instance methods are curried functions which take the instance as the first argument. Therefore

class A {
    func launch(code: Int) -> Bool { return false }

    func foo() {
        let cl = A.launch(self) 
        // Alternatively:
        let cl = self.dynamicType.launch(self)

        // ...
    }
}

b $ b

给你一个类型 Int - > Bool 。

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