函数声明/Function Declarations

Keep short function declarations on one line including the opening brace:

保持函数的声明语句在一行以内，包括左括号：

func reticulateSplines(spline: [Double]) -> Bool {
  // reticulate code goes here
}

For functions with long signatures, put each parameter on a new line and add an extra indent on subsequent lines:

对于函数名较长的情况，需要保证每个参数新起一行，且在该行的开始处添加一个缩进符：

func reticulateSplines(
  spline: [Double],
  adjustmentFactor: Double,
  translateConstant: Int, 
  comment: String
) -> Bool {
  // reticulate code goes here
}

Don't use (Void) to represent the lack of an input; simply use (). Use Void instead of () for closure and function outputs.

不要使用 (Void) 来表示入参为空的情况，用 () 即可。在闭包和函数的输出参数为空的情况时，推荐使用 Void, 而不是 ()。

推荐（Preferred）:

func updateConstraints() -> Void {
  // magic happens here
}

typealias CompletionHandler = (result) -> Void

不推荐（Not Preferred）:

func updateConstraints() -> () {
  // magic happens here
}

typealias CompletionHandler = (result) -> ()

函数调用/Function Calls

Mirror the style of function declarations at call sites. Calls that fit on a single line should be written as such:

调用代码应该和函数声明风格一致。如果调用函数只需要一行就可以完成，应当像下面这样组织代码：

let success = reticulateSplines(splines)

If the call site must be wrapped, put each parameter on a new line, indented one additional level:

当函数调用必须换行时，需要让每个参数新起一行并添加缩进：

let success = reticulateSplines(
  spline: splines,
  adjustmentFactor: 1.3,
  translateConstant: 2,
  comment: "normalize the display")