Filtering a Scala List by type

Question

I have a class structure like this

abstract class A
class B extends A
class C extends A
class D extends A
class E extends A

and I have a co

Answer 1

flatMap that shit! (as they say):

scala> val ys = xs flatMap {
     |   case _: B | _: C => None
     |   case other => Some(other)
     | }
ys: List[A] = List(D@7ecdc97b, E@2ce07e6b, E@468bb9d1)

In your case you were getting a List[ScalaObject] because ScalaObject is the least upper bound of None, D, and E.