Question

I thought I understood Go’s classes and Method Receivers, but apparently not. They generally work intuitively, but here’s an example where using one appears to cause an ‘undefined: Wtf’ error:

package main

type Writeable struct {
    seq int
}

func (w Writeable) Wtf() { // causes a compile error
//func Wtf() { // if you use this instead, it works
}

func Write() {
    Wtf() // this is the line that the compiler complains about
}

func main() {
}

I am using a compiler downloaded from golang within the last month or so, and LiteIDE. Please explain!

Answer 1

You’re defining Wtf() as a method of Writeable. Then you’re trying to use it without a struct instance. I changed your code below to create a struct and then use Wtf() as the method of that struct. Now it compiles. http://play.golang.org/p/cDIDANewar

package main

type Writeable struct {
    seq int
}

func (w Writeable) Wtf() { // causes a compile error
//func Wtf() { // if you use this instead, it works
}

func Write() {
    w := Writeable{}
    w.Wtf() // this is the line that the compiler complains about
}

func main() {
}