neaten the responder chain walking code

Author: mattneub

bk1ch11p472action/bk1ch11p472action/ViewController.swift

@@ -32,11 +32,8 @@ class ViewController: UIViewController {
     // rewritten to avoid use of C-style for loop
 
     @IBAction func showResponderChain(sender: UIResponder) {
-        var r : UIResponder? = sender
-        while r != nil {
-            print(r!)
-            r = r!.nextResponder()
-        }
+        var r : UIResponder! = sender
+        repeat { print(r, "\n"); r = r.nextResponder() } while r != nil
     }
 
 }

bk2ch09p476popovers/ch22p751popovers/ViewController.swift

@@ -190,9 +190,9 @@ class ViewController : UIViewController {
 
     }
 
-    func done (sender:AnyObject) {
-        var r = sender as! UIResponder
-        repeat { r = r.nextResponder()! } while !(r is UIViewController)
+    func done (sender:UIResponder) {
+        var r : UIResponder! = sender
+        repeat { r = r.nextResponder() } while !(r is UIViewController)
         (r as! UIViewController).dismissViewControllerAnimated(true, completion: {
             print("dismissed")
             })