| // +build OMIT |
| |
| package main |
| |
| import ( |
| "fmt" |
| "math/rand" |
| "time" |
| ) |
| |
| // START1 OMIT |
| func main() { |
| c := boring("Joe") |
| for { |
| select { |
| case s := <-c: |
| fmt.Println(s) |
| case <-time.After(1 * time.Second): // HL |
| fmt.Println("You're too slow.") |
| return |
| } |
| } |
| } |
| // STOP1 OMIT |
| |
| // START2 OMIT |
| func boring(msg string) <-chan string { // Returns receive-only channel of strings. // HL |
| c := make(chan string) |
| go func() { // We launch the goroutine from inside the function. // HL |
| for i := 0; ; i++ { |
| c <- fmt.Sprintf("%s: %d", msg, i) |
| time.Sleep(time.Duration(rand.Intn(1500)) * time.Millisecond) |
| } |
| }() |
| return c // Return the channel to the caller. // HL |
| } |
| // STOP2 OMIT |
| |
| |
| // START3 OMIT |
| func fanIn(input1, input2 <-chan string) <-chan string { // HL |
| c := make(chan string) |
| go func() { |
| for { |
| select { |
| case s := <-input1: |
| c <- s |
| case s := <-input2: |
| c <- s |
| } |
| } |
| }() |
| return c |
| } |
| // STOP3 OMIT |