Merge pull request mouredev#4978 from hozlucas28/Solution-29-Go

#29 - Go

Roadmap/29 - SOLID ISP/go/hozlucas28.go

@@ -0,0 +1,272 @@
+package main
+
+import (
+	"fmt"
+)
+
+/* -------------------------------------------------------------------------- */
+/*                                 INTERFACES                                 */
+/* -------------------------------------------------------------------------- */
+
+type BadVehicle interface {
+	Drive()
+	Fly()
+}
+
+type AirVehicle interface {
+	Fly()
+}
+
+type LandVehicle interface {
+	Drive()
+}
+
+type BlackAndWhitePrinter interface {
+	Print()
+}
+
+type ColorPrinter interface {
+	Print()
+}
+
+type MultifunctionalPrinter interface {
+	Print()
+	Scan()
+	SendFax()
+}
+
+/* -------------------------------------------------------------------------- */
+/*                                   CLASSES                                  */
+/* -------------------------------------------------------------------------- */
+
+/* ------------------------------- BadAirplane ------------------------------ */
+
+type badAirplane struct{}
+
+func NewBadAirplane() BadVehicle {
+	var airplane badAirplane = badAirplane{}
+	return &airplane
+}
+
+func (airplane *badAirplane) Drive() {
+	panic("Airplanes do not drive")
+
+}
+
+func (airplane *badAirplane) Fly() {
+	fmt.Println("The airplane is flying!")
+}
+
+/* --------------------------------- BadCar --------------------------------- */
+
+type badCar struct{}
+
+func NewBadCar() BadVehicle {
+	var car badCar = badCar{}
+	return &car
+}
+
+func (car *badCar) Drive() {
+	fmt.Println("The car is driving!")
+}
+
+func (car *badCar) Fly() {
+	panic("Cars do not fly")
+}
+
+/* ------------------------------ GoodAirplane ------------------------------ */
+
+type goodAirplane struct{}
+
+func NewGoodAirplane() AirVehicle {
+	var airplane goodAirplane = goodAirplane{}
+	return &airplane
+}
+
+func (airplane *goodAirplane) Fly() {
+	fmt.Println("The airplane is flying!")
+}
+
+/* --------------------------------- GoodCar -------------------------------- */
+
+type goodCar struct{}
+
+func NewGoodCar() LandVehicle {
+	var car goodCar = goodCar{}
+	return &car
+}
+
+func (car *goodCar) Drive() {
+	fmt.Println("The car is driving!")
+}
+
+/* -------------------------- BlackAndWhitePrinter -------------------------- */
+
+type blackAndWhitePrinter struct{}
+
+func NewBlackAndWhitePrinter() BlackAndWhitePrinter {
+	var printer blackAndWhitePrinter = blackAndWhitePrinter{}
+	return &printer
+}
+
+func (printer *blackAndWhitePrinter) Print() {
+	fmt.Println("Paper printed in black and white!")
+}
+
+/* ------------------------------ ColorPrinter ------------------------------ */
+
+type colorPrinter struct{}
+
+func NewColorPrinter() ColorPrinter {
+	var printer colorPrinter = colorPrinter{}
+	return &printer
+}
+
+func (printer *colorPrinter) Print() {
+	fmt.Println("Paper printed in color!")
+}
+
+/* ------------------------- MultifunctionalPrinter ------------------------- */
+
+type multifunctionalPrinter struct{}
+
+func NewMultifunctionalPrinter() MultifunctionalPrinter {
+	var printer multifunctionalPrinter = multifunctionalPrinter{}
+	return &printer
+}
+
+func (printer *multifunctionalPrinter) Print() {
+	fmt.Println("Paper printed!")
+}
+
+func (printer *multifunctionalPrinter) Scan() {
+	fmt.Println("Scan completed!")
+}
+
+func (printer *multifunctionalPrinter) SendFax() {
+	fmt.Println("Fax sent!")
+}
+
+/* -------------------------------------------------------------------------- */
+/*                                    MAIN                                    */
+/* -------------------------------------------------------------------------- */
+
+func main() {
+	/*
+		Interface Segregation Principle (ISP)...
+	*/
+
+	fmt.Println("Interface Segregation Principle (ISP)...")
+
+	fmt.Println("\nBad implementation of Interface Segregation Principle (ISP)...")
+
+	fmt.Println("\n```\n" + `type BadVehicle interface {
+  Drive()
+  Fly()
+}
+
+type badAirplane struct{}
+
+func NewBadAirplane() BadVehicle {
+  var airplane badAirplane = badAirplane{}
+  return &airplane
+}
+
+func (airplane *badAirplane) Drive() {
+  panic("Airplanes do not drive")
+
+}
+
+func (airplane *badAirplane) Fly() {
+  fmt.Println("The airplane is flying!")
+}
+
+type badCar struct{}
+
+func NewBadCar() BadVehicle {
+  var car badCar = badCar{}
+  return &car
+}
+
+func (car *badCar) Drive() {
+  fmt.Println("The car is driving!")
+}
+
+func (car *badCar) Fly() {
+  panic("Cars do not fly")
+}` + "\n```")
+
+	fmt.Println(
+		"\nThis is a bad implementation of Interface Segregation Principle (ISP),\n" +
+			"because the 'badAirplane' class and the 'badCar' class should not implement\n" +
+			"an interface with methods that they are going to never use. So, the implemented\n" +
+			"interface ('BadVehicle') is to general for both classes.",
+	)
+
+	fmt.Println("\nGood implementation of Interface Segregation Principle (ISP)...")
+
+	fmt.Println("\n```\n" + `type AirVehicle interface {
+  Fly()
+}
+
+type LandVehicle interface {
+  Drive()
+}
+
+type goodAirplane struct{}
+
+func NewGoodAirplane() AirVehicle {
+  var airplane goodAirplane = goodAirplane{}
+  return &airplane
+}
+
+func (airplane *goodAirplane) Fly() {
+  fmt.Println("The airplane is flying!")
+}
+
+type goodCar struct{}
+
+func NewGoodCar() LandVehicle {
+  var car goodCar = goodCar{}
+  return &car
+}
+
+func (car *goodCar) Drive() {
+  fmt.Println("The car is driving!")
+}` + "\n```")
+
+	fmt.Println(
+		"\nThis is a good implementation of Interface Segregation Principle (ISP),\n" +
+			"because the 'goodAirplane' class and the 'goodCar' class only implements\n" +
+			"the necessary methods, without any extras.",
+	)
+
+	fmt.Println(
+		"\n# ---------------------------------------------------------------------------------- #",
+	)
+
+	/*
+	   Additional challenge...
+	*/
+
+	fmt.Println("\nAdditional challenge...")
+
+	var blackAndWhitePrinter BlackAndWhitePrinter = NewBlackAndWhitePrinter()
+	var colorPrinter ColorPrinter = NewColorPrinter()
+	var multifunctionalPrinter MultifunctionalPrinter = NewMultifunctionalPrinter()
+
+	fmt.Println()
+	blackAndWhitePrinter.Print()
+
+	fmt.Println()
+	colorPrinter.Print()
+
+	fmt.Println()
+	multifunctionalPrinter.Print()
+
+	fmt.Println()
+	multifunctionalPrinter.Scan()
+
+	fmt.Println()
+	multifunctionalPrinter.SendFax()
+}