nl_tokens: Helper function for finding the view - sequence node at the given position .
pl_tokens: function _getViewSequenceAtIndex ( index , startViewSequence ) { if ( this . _viewSequence . getAtIndex ) { return this . _viewSequence . getAtIndex ( index , startViewSequence ) ; } var viewSequence = startViewSequence || this . _viewSequence ; var i = viewSequence ? viewSequence . getIndex ( ) : index ; if ( index > i ) { while ( viewSequence ) { viewSequence = viewSequence . getNext ( ) ; if ( ! viewSequence ) { return undefined ; } i = viewSequence . getIndex ( ) ; if ( i === index ) { return viewSequence ; } else if ( index < i ) { return undefined ; } } } else if ( index < i ) { while ( viewSequence ) { viewSequence = viewSequence . getPrevious ( ) ; if ( ! viewSequence ) { return undefined ; } i = viewSequence . getIndex ( ) ; if ( i === index ) { return viewSequence ; } else if ( <mask> > i ) { return undefined ; } } } return viewSequence ; }