routine.go

package main

import "fmt"

func sender(to chan string, done chan bool) {
	for {
		select {
		case t := <-to:
			fmt.Println(t)
		case <-done:
			break
		}
	}
}

func main() {
	strs := []string{
		"a",
		"b",
		"c",
		"d",
	}

	ch := make(chan string, len(strs))
	done := make(chan bool)

	go sender(ch, done)

	for _, v := range strs {
		ch <- v
	}
	done <- true
}