Custom extractors with nested types.

case class Foo(val x: Int, val y: Int)
    
class Bar(val f: Foo, val s: String)
object Bar {
  def apply(x: Int, y: Int, s: String): Bar = new Bar(Foo(x, y), s)
  def unapply(b: Bar): Option[(Int, Int, String)] = Some((b.f.x, b.f.y, b.s))
}

val a = Bar(1, 2, "A")

a match {
  case Bar(x, y, s) => println(x + "" + y + s) // prints "12A"
}