Java or Kotlin support functors or monads as design patterns, i.e. this is how a map/flatMap works with an Optional or a Stream. The question is: if this suppo

Java or Kotlin support functors or monads as design patterns, i.e. this is how a map/flatMap works with an Optional or a Stream. The question is: if this support is enough or should the type system be enhanced so you can abstract over/compose a functor and/or a monad ? The answer to this question is IMO still open.