update: powerdrawer interface

interfaces/04-interfaces/power/main.go

@@ -13,52 +13,38 @@ import (
 	"time"
 )
 
-// Socket has the power!
-type Socket struct {
-	power int
-}
-
-// Plug a device to draw power from the `Socket`
-func (s *Socket) Plug(device PowerDrawer) {
-	n := rand.Intn(50)
-	s.power -= n
-	device.Draw(n)
-}
-
-// PowerDrawer can be any type that can be powered
-type PowerDrawer interface {
-	Draw(power int)
-}
-
-// -----
-
-// Kettle can be powered
-type Kettle struct{}
-
-// Draw power to a Kettle
-func (Kettle) Draw(power int) {
-	fmt.Printf("Kettle is drawing %dkW of electrical power.\n", power)
-}
-
-// Mixer can be powered
-type Mixer struct{}
-
-// Draw power to a Mixer
-func (Mixer) Draw(power int) {
-	fmt.Printf("Mixer is drawing %dkW of electrical power.\n", power)
-}
-
-// -----
+// RUN IT WITH ALL THE FILES IN THE DIRECTORY LIKE SO:
+// go run .
 
 func main() {
 	rand.Seed(time.Now().UnixNano())
 
-	kettle := Kettle{}
-	mixer := Mixer{}
+	var (
+		blender Blender
+		player  Player
+		kettle  Kettle
+		mixer   Mixer
+	)
 
 	socket := &Socket{100}
-	socket.Plug(kettle)
-	socket.Plug(mixer)
+
+	fmt.Printf("Socket's available power is %d kW.\n", socket.power)
+
+	if err := socket.Plug(blender); err != nil {
+		fmt.Println("Blender cannot be powered up:", err)
+	}
+
+	if err := socket.Plug(player); err != nil {
+		fmt.Println("Player cannot be powered up:", err)
+	}
+
+	if err := socket.Plug(kettle); err != nil {
+		fmt.Println("Kettle cannot be powered up:", err)
+	}
+
+	if err := socket.Plug(mixer); err != nil {
+		fmt.Println("Mixer cannot be powered up:", err)
+	}
 
 	fmt.Printf("Socket's available power is %d kW.\n", socket.power)
 }