Update to Swift 4.2

- Incorporate conditional compilation blocks for Swift 4.2 into the main code, replacing older Swift code.
- Add CaseIterable to OctopusDirection
- Replace arc4random and other legacy randomization features with native Swift randomization.
- Remove CGFloat.randomInteger in favor of CGFloat(Int(CGFloat.random(in:)))
- Improve formatting in Int+OctopusKit.

Author: ShinryakuTako

Sources/OctopusKit/Apple API Extensions/CoreGraphics/CGFloat+OctopusKit.swift

@@ -10,17 +10,6 @@ import CoreGraphics
 
 extension CGFloat {
 
-    // MARK: - Random Numbers
+    // NOTE: Randomization extensions removed in favor of `CGFloat(Int(CGFloat.random(in:)))` etc.
 
-    /// Returns a random **integer** between the lower and upper bounds, **inclusive**.
-    ///
-    /// Equivalent to calling `Int.random(from:to:)` (an OctopusKit extension) and converting it to `CGFloat`.
-    ///
-    /// Uses `arc4random_uniform(_:)`. For GameplayKit-based randomization, use the extensions of `GKRandom`.
-    public static func randomInteger(from lowerBound: CGFloat, to upperBound: CGFloat) -> CGFloat {
-        // TODO: CHECK: Relevance after Swift 4.2 is released.
-        
-        // Provided as a convenience to avoid having to explicitly cast from `Int` because working with SpriteKit primarily involves `CGFloat`.
-        return CGFloat(Int.random(from: Int(lowerBound), to: Int(upperBound)))
-    }
 }

Sources/OctopusKit/Apple API Extensions/Foundation/Array+OctopusKit.swift

@@ -15,20 +15,7 @@ import GameplayKit
 extension Array {
 
     // MARK: - Randomization
-    
-    #if swift(>=4.2)
-    // TODO: Remove `randomElement()` after Swift 4.2 is released.
-    #else
-    /// Returns a random element from this array.
-    ///
-    /// Uses `arc4random_uniform(_:)`.
-    ///
-    /// Can be used with array literals, e.g.: `[4, 8, 16, 42].randomElement()`
-    public func randomElement() -> Element {
-        return self[Int(arc4random_uniform(UInt32(self.count)))]
-    }
-    #endif
-    
+        
     /// Returns a random element from this array whose index is not in `skippingIndices`.
     ///
     /// If the array is empty or if the list of exclusions prevents any acceptable value within `maximumAttempts`, `nil` is returned.

Sources/OctopusKit/Apple API Extensions/Foundation/Double+OctopusKit.swift

@@ -18,12 +18,7 @@ extension Double {
     public static func unitRandom() -> Double {
         // CREDIT: Apple Adventure Sample
 
-        #if swift(>=4.2)
-        // TODO: Remove `arc4random` variant after Swift 4.2 is released.
         let quotient = Double(Int.random(in: 0...Int.max)) / Double(Int.max) // CHECK: Is `0...Int.max` the same range as `arc4random()`?
-        #else
-        let quotient = Double(arc4random()) / Double(UInt32.max)
-        #endif
 
         return quotient
     }

Sources/OctopusKit/Apple API Extensions/Foundation/Int+OctopusKit.swift

@@ -14,22 +14,6 @@ extension Int {
 
     // MARK: - Random Numbers
 
-    /// Returns a random integer between the lower and upper bounds, **inclusive**.
-    ///
-    /// Uses `arc4random_uniform(_:)`. For GameplayKit-based randomization, use the extensions of `GKRandom`.
-    public static func random(from lowerBound: Int, to upperBound: Int) -> Int {
-        assert(lowerBound < upperBound, "`lowerBound` should be less than `upperBound`") // Assert instead of silently failing, because anything that relies on random numbers better get random numbers.
-        
-        #if swift(>=4.2)
-        // TODO: Remove `random(from:to:)` after Swift 4.2 is released.
-        return self.random(in: lowerBound...upperBound)
-        #else
-        let upperBoundInclusive = (upperBound + 1) - lowerBound // + 1 so the upper bound is included.
-        let randomNumber = Int(arc4random_uniform(UInt32(upperBoundInclusive)))
-        return randomNumber + lowerBound
-        #endif
-    }
-    
     /// Returns a random integer from `0` to `upperBound-1` (**not** including `upperBound`) that does not match any of the numbers provided in the exclusion list.
     ///
     /// This method repeatedly calls the random number generator until it returns a number that is not in the exclusions list. If no acceptable number can be generated in `maximumAttempts` then `nil` will returned.
@@ -60,31 +44,20 @@ extension Int {
         // If there are no exclusions, just return the first random number generated.
 
         if exclusions.isEmpty {
-            #if swift(>=4.2)
-            // TODO: Remove `arc4random` variant after Swift 4.2 is released.
             return self.random(in: 0 ..< upperBound)
-            #else
-            return Int(arc4random_uniform(UInt32(upperBound)))
-            #endif
         }
         else {
-            
             var randomNumber: Int
             var attempts = 0
 
             // Keep generating random numbers until we find one that's not in the exclusions list, or we've made the maximum number of attempts, so that we don't get stuck in an infinite loop.
 
             repeat {
-                
-                #if swift(>=4.2)
-                // TODO: Remove `arc4random` variant after Swift 4.2 is released.
                 randomNumber = self.random(in: 0 ..< upperBound)
-                #else
-                randomNumber = Int(arc4random_uniform(UInt32(upperBound)))
-                #endif
-                
                 attempts += 1
-            } while exclusions.contains(randomNumber) && attempts < maximumAttempts
+                
+            } while exclusions.contains(randomNumber)
+                 && attempts < maximumAttempts
 
             if !exclusions.contains(randomNumber) {
                 return randomNumber

Sources/OctopusKit/Apple API Extensions/SpriteKit/SKNode+OctopusKit.swift

@@ -18,10 +18,8 @@ extension SKNode {
     public class func nodeWithName<T>(name: String) -> T? {
         // CREDIT: Apple Adventure Sample
 
-        // TODO: Review for Swift 4.2 and iOS 12 when released.
-        // return (try? NSKeyedUnarchiver.unarchivedObject(ofClasses: [SKNode.self], from: Data(contentsOf: Bundle.main.url(forResource: name, withExtension: "sks")!))) as? T
-
-        return NSKeyedUnarchiver.unarchiveObject(withFile: Bundle.main.path(forResource: name, ofType: "sks")!) as? T
+        // TODO: Verify the functionality of this Swift 4.2/iOS 12 update.
+        return (try? NSKeyedUnarchiver.unarchivedObject(ofClasses: [SKNode.self], from: Data(contentsOf: Bundle.main.url(forResource: name, withExtension: "sks")!))) as? T
     }
 
     /// MARK: - Initializers

Sources/OctopusKit/Components/Input/ImpactVibrationComponent.swift

@@ -6,20 +6,16 @@
 //  Copyright © 2018 Invading Octopus. Licensed under Apache License v2.0 (see LICENSE.txt)
 //
 
+import SpriteKit
 import GameplayKit
 
-#if swift(>=4.2)
-// TODO: Remove this temporary alias and incorporate changes into main code after Swift 4.2 launches.
-public typealias UIImpactFeedbackStyle = UIImpactFeedbackGenerator.FeedbackStyle
-#endif
-
 #if os(iOS)
 
 public final class ImpactVibrationComponent: VibrationComponent<UIImpactFeedbackGenerator> {
 
-    public var style: UIImpactFeedbackStyle
+    public var style: UIImpactFeedbackGenerator.FeedbackStyle
 
-    public init(style: UIImpactFeedbackStyle = .light) {
+    public init(style: UIImpactFeedbackGenerator.FeedbackStyle = .light) {
         self.style = style
         super.init()
     }

Sources/OctopusKit/Core/Launch/OctopusAppDelegate-iOS.swift

@@ -28,13 +28,8 @@ class OctopusAppDelegate: UIResponder, UIApplicationDelegate {
     /// The Xcode project templates usually include a synthesized declaration of the property automatically for the app delegate. The default value of this synthesized property is `nil`, which causes the app to create a generic `UIWindow` object and assign it to the property. If you want to provide a custom window for your app, you must implement the getter method of this property and use it to create and return your custom window.
     var window: UIWindow?
 
-    #if swift(>=4.2)
-    // TODO: Remove this temporary alias and incorporate changes into main code after Swift 4.2 launches.
-    public typealias UIApplicationLaunchOptionsKey = UIApplication.LaunchOptionsKey
-    #endif
-    
     /// Override point for customization after game launch.
-    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
+    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
 
         OctopusKit.logForFramework.add()
 

Sources/OctopusKit/Core/Launch/OctopusSceneController-Universal.swift

@@ -112,16 +112,9 @@ public class OctopusSceneController: OSViewController, OctopusSceneDelegate {
         didSet { self.setNeedsUpdateOfHomeIndicatorAutoHidden() }
     }
 
-    #if swift(>=4.2)
-    // TODO: Remove this conditional compilation flag and incorporate changes into main code after Swift 4.2 launches.
     public override var prefersHomeIndicatorAutoHidden: Bool {
         return prefersHomeIndicatorAutoHiddenOverride
     }
-    #else
-    public override func prefersHomeIndicatorAutoHidden() -> Bool {
-        return prefersHomeIndicatorAutoHiddenOverride
-    }
-    #endif
 
     /// Specifies whether whether the scene controller'€™s contents should auto rotate.
     ///

Sources/OctopusKit/Miscellaneous/OctopusDirection.swift

@@ -6,13 +6,12 @@
 //  Copyright © 2018 Invading Octopus. Licensed under Apache License v2.0 (see LICENSE.txt)
 //
 
-// TODO: `CaseIterable` in Swift 4.2
-// TODO: Support for degrees
+// TODO: Support for degrees?
 // CHECK: Internationalization for string representations?
 
 import SpriteKit
 
-public enum OctopusDirection: String, CustomStringConvertible {
+public enum OctopusDirection: String, CustomStringConvertible, CaseIterable {
 
     case north
     case northEast