Timers – running something later

If you want to do something later, use time.Timer. A Timer is a nice way of doing the following:

// This is only for illustration. Don't do this!
type TimerMockup struct {
     C chan<- time.Time
}
 
func NewTimerMockup(dur time.Duration) *TimerMockup {
     t := &TimerMockup{
          C: make(chan time.Time,1),
     }
     go func() {
          // Sleep, and then send to the channel
          time.Sleep(dur)
          t.C <- time.Now()
          }()
     return t
}

So, a timer is like a goroutine that will send a message to a channel after sleeping for...