Message-passing with channels.

message.go

package main

import "fmt"

type Greeter struct{}

func (p *Greeter) greet(s string) {
	fmt.Printf("Hello, %s!\n", s)
}

func CreateGreeter(ch chan string) *Greeter {
	greeter := &Greeter{}
	go func(ch chan string) {
		for s := range ch {
			greeter.greet(s)
		}
	}(ch)
	return greeter
}

func main() {
	ch := make(chan string)
	CreateGreeter(ch)
	ch <- "World"

	// wait for input
	var s string
	fmt.Scanln(&s)
}