| // +build ignore,OMIT |
| |
| package main |
| |
| import ( |
| "fmt" |
| "math/rand" |
| "time" |
| ) |
| |
| // START1 OMIT |
| func main() { |
| c := fanIn(boring("Joe"), boring("Ann")) // HL |
| for i := 0; i < 10; i++ { |
| fmt.Println(<-c) // HL |
| } |
| fmt.Println("You're both boring; I'm leaving.") |
| } |
| // 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(1e3)) * 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() { // HL |
| for { |
| select { // HL |
| case s := <-input1: c <- s // HL |
| case s := <-input2: c <- s // HL |
| } // HL |
| } |
| }() |
| return c |
| } |
| // STOP3 OMIT |