added playground page for interface segregation

Author: Sebastian Boldt

GOFSwift.xcworkspace/xcuserdata/sboldt.xcuserdatad/UserInterfaceState.xcuserstate

@@ -67,6 +67,6 @@
 
 ✅ Open Closed Principle (OCP)
 
-❌ Liskov Substitution Principle (LSP)
+✅ Interface Segregation Principle (ISP)
 
-❌ Interface Segregation Principle (ISP)
+❌ Liskov Substitution Principle (LSP)

README.md

@@ -2,6 +2,96 @@
 
 import Foundation
 
-var str = "Hello, playground"
+// Fat protocol - Problem
+
+protocol FatProtocol {
+    func tap()
+    func doubleTap()
+    func longTap()
+}
+
+struct ExtendedButton: FatProtocol {
+    func tap() {
+        
+    }
+    
+    func doubleTap() {
+        
+    }
+    
+    func longTap() {
+        
+    }
+}
+
+struct SimpleButton: FatProtocol {
+    func tap() {
+        // The SimpleButton just needs to implement this function
+        // All the other functions are irrelavant
+    }
+    
+    func doubleTap() {
+    }
+    
+    func longTap() {
+    }
+}
+
+
+// Fat protocol - Solution
+
+protocol Tappable {
+    func tap()
+}
+
+protocol DoubleTappable {
+    func doubleTap()
+}
+
+protocol LongTappable {
+    func longTap()
+}
+
+
+struct AnotherSimpleButton: Tappable {
+    func tap() {
+        // Now we just need to implement the methods we really need.
+    }
+}
+
+// Fat class - Problem
+
+struct Video {
+    var title: String
+    var description: String
+    var data: Data
+    var metaData: String
+    var fileType: String
+}
+
+// The log functions just needs title and description.
+func log(video: Video) {
+    print("\(video.title), \(video.description)")
+}
+
+// Fat class - Solution
+
+protocol Loggable {
+    var title: String { get }
+    var description: String { get }
+}
+
+struct BetterVideo: Loggable {
+    var title: String
+    var description: String
+    var data: Data
+    var metaData: String
+    var fileType: String
+}
+
+// The log functions just needs title and description.
+func betterLog(loggable: Loggable) {
+    print("\(loggable.title), \(loggable.description)")
+}
 
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