Swift中的多行语句 [英] Multiline statement in Swift

问题描述

我正在研究Swift教程，发现Swift有一种奇怪的方式来处理多行语句.

I was working on a Swift tutorial and found that Swift has a strange way to handle multi-line statement.

首先，我定义了对标准String类的一些扩展:

First, I defined some extension to the standard String class:

extension String {
    func replace(target: String, withString: String) -> String {
        return self.stringByReplacingOccurrencesOfString(target, withString: withString)
    }

    func toLowercase() -> String {
        return self.lowercaseString
    }
}

这可以按预期工作:

let str = "HELLO WORLD"
let s1 = str.lowercaseString.replace("hello", withString: "goodbye") // -> goodbye world

这不起作用:

let s2 = str
            .lowercaseString
            .replace("hello", withString: "goodbye")
// Error: could not find member 'lowercaseString'

如果我用函数调用替换对lowercaseString属性的引用，它将再次起作用:

If I replace the reference to the lowercaseString property with a function call, it works again:

let s3 = str
            .toLowercase()
            .replace("hello", withString: "goodbye") // -> goodbye world

Swift语言规范中是否有任何东西可以防止某个属性折断在自己的行上?

Is there anything in the Swift language specifications that prevent a property to be broken onto its own line?

位于快速存根的代码.

推荐答案

这绝对是编译器错误. Xcode 7 beta 3中的问题已解决.

This is definitely a compiler bug. Issue has been resolved in Xcode 7 beta 3.

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