[O] Implement obj.apply {} like Kotlin

ProjectClock/AlarmActivator.swift

@@ -56,8 +56,11 @@ class AlarmActivator: UITabBarController
         guard let alarm = alarms.listActivating.first else { return }
         
         // Update alarm info
-        alarm.lastActivate = Date()
+        alarm.apply {
-        if alarm.oneTime { alarm.enabled = false }
+            $0.lastActivate = Date()
+            if $0.oneTime { $0.enabled = false }
+        }
+        
         alarms.localSave()
         
         // Segue

ProjectClock/Models.swift

@@ -100,13 +100,13 @@ class Alarms: Codable
     var list: [Alarm] = []
     
     /// Save alarms to local storage
-    func localSave() -> Alarms { localStorage.setValue(JSON.stringify(list)!, forKey: "alarms"); return self }
+    func localSave() { localStorage.setValue(JSON.stringify(list)!, forKey: "alarms") }
     
     /// Read alarms from local storage
-    func localRead() -> Alarms { list = JSON.parse([Alarm].self, localStorage.string(forKey: "alarms")!)!; return self }
+    func localRead() { list = JSON.parse([Alarm].self, localStorage.string(forKey: "alarms")!)! }
     
     /// Read an alarm object from local storage
-    static func fromLocal() -> Alarms { return Alarms().localRead() }
+    static func fromLocal() -> Alarms { return Alarms().apply { $0.localRead() } }
     
     /// Get enabled alarms
     var listEnabled: [Alarm] { return list.filter { $0.enabled } }

ProjectClock/Utils.swift

@@ -77,3 +77,17 @@ extension TimeInterval
         else { return "\(seconds)s" }
     }
 }
+
+/// Apply like Kotlin
+protocol HasApply {}
+extension HasApply
+{
+    @discardableResult
+    func apply(_ c: (Self) -> ()) -> Self
+    {
+        c(self)
+        return self
+    }
+}
+extension Alarm: HasApply {}
+extension Alarms: HasApply {}