anchor.diff:  
   
       member this.HandleSwipe(gr : UISwipeGestureRecognizer) =
  -        printfn "%A" gr.Direction
  +        this.MySnakeView.MoveTowards <| 
  +        match gr.Direction with
  +        | UISwipeGestureRecognizerDirection.Up -> Up
  +        | UISwipeGestureRecognizerDirection.Left -> Left
  +        | UISwipeGestureRecognizerDirection.Right -> Right
  +        | UISwipeGestureRecognizerDirection.Down -> Down
  +        | _ -> Up
   
       // Return true for supported orientations
       override this.ShouldAutorotateToInterfaceOrientation(orientation) = 
  
positive.code:         | Left -> (x - 1, y)
          | Right -> (x + 1, y)
  
  
  [<Register("smallViewController")>]
  type smallViewController() = 
      inherit UIViewController()
  
      // Release any cached data, images, etc that aren't in use.
      override this.DidReceiveMemoryWarning() = 
  
negative.code:             this.View.Bounds.Height - 50.0f,
              100.0f,
              44.0f)
          b.TouchUpInside.Add (fun x -> this.MySnakeView.Step())
          this.View.AddSubview(b)
  
          let lft = new UISwipeGestureRecognizer(Action<_> this.HandleSwipe)
  