initial commit

channel-directions/channeldirections.go

@@ -0,0 +1,25 @@
+package main
+
+import "fmt"
+
+//this func only accepts a channel for sending values.
+//it would be a compile-time error
+//to try to receive on this channel.
+func ping(pings chan<- string,msg string){
+	pings <- msg
+}
+
+//this pong function accepts one channel for receives (pings)
+//and a second for sends(pongs)
+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)
+}