sealed.scala

class Foo {
  sealed trait A
  case class A1(x: Int) extends A
  case class A2(y: String) extends A
  case class A3(z: Double) extends A

  sealed trait B
  case class B1(z: Int) extends B
  case class B2(z1: Int) extends B

  case class Carrier(a: A, b: B)
  def foo(c: Carrier): Unit = c match {
    case Carrier(A1(x), B1(y)) => println(x + y)
  }

  def bar(a: A, b: B): Unit = (a, b) match {
    case (A1(x), _) => println(x)
    case (A2(y), _) => println(y)
  }
}