anchor.diff:        this.rawKeyUpStream,
         this.rawKeyDownStream,
         this.rawKeyCombinedStream,
  -      { allowShiftOnlyHotKeys, allowAltKeyPress, navKeys })
  +      { allowShiftOnlyHotKeys, allowAltKeyPress, navKeys, delKeys })
             : this.allowShiftOnlyHotKeys = allowShiftOnlyHotKeys,
               this.allowAltKeyPress = allowAltKeyPress,
  -            this.navKeys = navKeys;
  +            this.navKeys = navKeys,
  +            this.delKeys = delKeys;
   
   
     Stream<String> get keyStream {
  
positive.code:     KeyCode.SINGLE_QUOTE: "'"
    };
  
    final Element _target;
    final Map<KeyCode, int> navKeys;
  
    final Stream<KeyEvent> rawKeyCombinedStream;
    final Stream<KeyEvent> rawKeyUpStream;
    final Stream<KeyEvent> rawKeyDownStream;
    final Stream<KeyEvent> rawKeyPressStream;
  
    bool allowShiftOnlyHotKeys;
    bool allowAltKeyPress;
  
    Stream<String> _keyStream;
    Stream<String> _lineStream;
    Stream<int>    _navStream;
    Stream<String> _hotKeyStream;
  
    factory ReactiveKeyboard(
        Element target, {
          bool allowShiftOnlyHotKeys: false,
          bool allowAltKeyPress: false,
          Map<int, int> navKeys
        }) {
      var rkp = KeyboardEventStream.onKeyPress(target);
      var rku = KeyboardEventStream.onKeyUp(target);
      var rkd = KeyboardEventStream.onKeyDown(target).map((key) {
        if (   key.keyCode == KeyCode.BACKSPACE
            || key.keyCode == KeyCode.DELETE
            || key.keyCode == KeyCode.NUM_DELETE) {
          key.preventDefault();
        }
  
        return key;
      });
  
      if (navKeys == null) {
        navKeys = NUM_NAV;
      }
  
      var rkc = rkp.transform(new MergeAll(3, [rku, rkd])).asBroadcastStream();
  
      return new ReactiveKeyboard._(target, rkp, rku, rkd, rkc,
          allowShiftOnlyHotKeys: allowShiftOnlyHotKeys,
          allowAltKeyPress: allowAltKeyPress, navKeys: navKeys);
    }
  
  
  
negative.code: 
  
  class ReactiveKeyboard {
    final Element _target;
    final Stream<KeyEvent> rawKeyCombinedStream;
    final Stream<KeyEvent> rawKeyUpStream;
    final Stream<KeyEvent> rawKeyDownStream;
    final Stream<KeyEvent> rawKeyPressStream;
  
    bool allowShiftOnlyHotKeys;
    bool allowAltKeyPress;
    Map<KeyCode, int> navKeys;
    List<int> delKeys;
  
    Stream<String> _keyStream;
    Stream<String> _lineStream;
    Stream<int>    _navStream;
    Stream<String> _hotKeyStream;
  
    // DOM event types consts
    static const String KEY_PRESS = 'keypress';
    static const String KEY_UP    = 'keyup';
  