> However an optional is really just a list constrained to size 0 or 1.
True, but you've only written about them as data types, which misses the monadic part. What makes them monads is that you can join any Optional<Optional<T>> into an Optional<T>. Likewise you can join a List<List<T>> into a List<T>. It is that principled 'smooshing down' of the data types that makes them monads.
True, but you've only written about them as data types, which misses the monadic part. What makes them monads is that you can join any Optional<Optional<T>> into an Optional<T>. Likewise you can join a List<List<T>> into a List<T>. It is that principled 'smooshing down' of the data types that makes them monads.