Fan In demonstration

fan.go

package main

import (
	"fmt"
	"math/rand"
	"time"
)

func main() {
	fmt.Println("start main")

	c := dostuff("Raymond")
	d := dostuff("Brandy")

	fanned := myFanIn(c, d)

	for i := 0; ; i++ {
		fmt.Printf("This is stuff: %s\n", <-fanned)
	}

	fmt.Println("Done")
}

func dostuff(word string) <-chan string {

	c := make(chan string)

	// If there is no go func here, it will not run..
	// Reason:
	go func() {

		for i := 0; ; i++ {
			c <- word
			time.Sleep(time.Duration(rand.Intn(10)) * time.Millisecond)
		}
	}()
	return c
}

func myFanIn(a, b <-chan string) <-chan string {
	result := make(chan string)
	go func() {

		for {
			select {
			case fromA := <-a:
				result <- fromA
			case fromB := <-b:
				result <- fromB
			}
		}
	}()

	return result
}