event: add some documentation

event/example_test.go

@@ -0,0 +1,42 @@
+package event
+
+import "fmt"
+
+func ExampleTypeMux() {
+	type someEvent struct{ I int }
+	type otherEvent struct{ S string }
+	type yetAnotherEvent struct{ X, Y int }
+
+	var mux TypeMux
+
+	// Start a subscriber.
+	done := make(chan struct{})
+	sub := mux.Subscribe(someEvent{}, otherEvent{})
+	go func() {
+		for event := range sub.Chan() {
+			fmt.Printf("Received: %#v\n", event)
+		}
+		fmt.Println("done")
+		close(done)
+	}()
+
+	// Post some events.
+	mux.Post(someEvent{5})
+	mux.Post(yetAnotherEvent{X: 3, Y: 4})
+	mux.Post(someEvent{6})
+	mux.Post(otherEvent{"whoa"})
+
+	// Stop closes all subscription channels.
+	// The subscriber goroutine will print "done"
+	// and exit.
+	mux.Stop()
+
+	// Wait for subscriber to return.
+	<-done
+
+	// Output:
+	// Received: event.someEvent{I:5}
+	// Received: event.someEvent{I:6}
+	// Received: event.otherEvent{S:"whoa"}
+	// done
+}