channel directions

packagemain

//channel directions

//通道作为函数参数，你需要指明通道是作为发送还是接受。

//这种指明提高了程序类型的安全

import "fmt"

func ping(pings chan<- string, msg string) {

    pings <- msg

}

// 通道作为参数

func pong(pings <-chan string, pongs chan<- string) {

    msg := <-pings

    pongs <- msg

}

func main() {

    pings := make(chan string, 1)

    pongs := make(chan string, 1)

    ping(pings, "passed message")

    pong(pings, pongs)

    fmt.Println(<-pongs)

}