Tour: Concurrency: Step 4: Channel should have not capacity

[rolandtritsch]

Context: https://tour.golang.org/concurrency/4

Hi All,

I think in the context of what this step is suppose to illustrate creating the channel with the capacity of the number of fibs you want to calculate is miss-leading.

For this to work the channel needs to have (and should have) a capacity of one (basically synchronizing the fib goroutine with the main goroutine (between calculating one number and displaying it)).

func main() {
	c := make(chan int)
	go fibonacci(10, c)
	for i := range c {
		fmt.Println(i)
	}
}

[crisman]

The code shows how range on a channel will continue until the channel is closed by the sending side. The capacity in the channel is there to allow fibonacci() to complete, sending all output over the channel, and close the channel if that (by scheduling chance) happens before the for loop starts reading from the channel.