无法在参数time.AfterFunc中使用func（）类型的函数

Question

I can't figure out how to solve this Go algorithm problem without running into a couple nested function problems. One of them being, "cannot use func literal (type func()) as type func() string in return argument".

The solution I'm working with right now is:

// Write a function that takes in 2 numbers (a, b) and a function.
// It should execute the function after a milliseconds, 
// and then execute the function again after b milliseconds.

        package main

        import "time"                  

        func newFunc(b int, fn func() string) func() string {
                return func() {        
                        time.AfterFunc(time.Duration(b)*time.Second, fn)
                }
        } 

        func solution10(a, b int, fn func() string) string { 
                f := newFunc(b, fn)    
                time.AfterFunc(time.Duration(a)*time.Second, f)
        }

I specified the return type of solution10 as string because the function I'll be passing in will be returning a string. Not sure if this is right either. An example of how I would call this solution:

func yourFunc() string {
            return "Hello world"
    } 

---

solution10(10, 100, yourFunc);

I'd love if someone can explain to me why I am getting that error (the return types of each function I'm passing in seem to be right.) Or if someone could just please offer a right solution for it so that I could learn tricks in how to solve these type of closure-related questions?

Answer 1

Because time.AfterFunc takes a func(), but you are using a func() string.

if you want to call a func() string you could wrap it

time.AfterFunc(time.Duration(b)*time.Second, func() {
    fn()
})