Go 中的函数声明语法

Function declaration syntax in Go

下面函数声明中的(c App)是什么?

func (c App) SaveSettings(setting string) revel.Result {
--------------------------------------------------------------------------------------
func                                                      Keyword to define a function
     (c App)                                              ????
             SaveSettings                                 Function name
                         (setting string)                 Function arguments
                                          revel.Result    Return type

(c App) 给出 receiver 的名称和类型,Go 等价于 C++ 或 JavaScript 的 this 或 Python 的 selfc 是接收者的名字,因为 in Go it's conventional to use a short, context-sensitive name instead of something generic like this. See http://golang.org/ref/spec#Method_declarations --

A method is a function with a receiver. The receiver is specified via an extra parameter section preceeding the method name.

及其示例:

func (p *Point) Length() float64 {
    return math.Sqrt(p.x * p.x + p.y * p.y)
}