I answered this in my other answer to you: https://news.ycombinator.com/item?id=7709395 https://news.ycombinator.com/item?id=7709395 It's a common misconcepti

I answered this in my other answer to you: https://news.ycombinator.com/item?id=7709395 https://news.ycombinator.com/item?id=7709395 It's a common misconception that interfaces are the only way to do polymorphism, because that's usually the only way in Java.