// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan. // License: https://creativecommons.org/licenses/by-nc-sa/4.0/ // See page 244. // Countdown implements the countdown for a rocket launch. package main import ( "fmt" "time" ) //!+ func main() { fmt.Println("Commencing countdown.") tick := time.Tick(1 * time.Second) for countdown := 10; countdown > 0; countdown-- { fmt.Println(countdown) <-tick } launch() } //!- func launch() { fmt.Println("Lift off!") }