// long
sealed trait Foo
case class Bar(x: Int) extends Foo
case class Baz(y: String) extends Foo
case object Quux extends Foo
case object Bah extends Foo

// short
data Foo {
  Bar(x: Int)
  Baz(y: String)
  Quux
  Bah
}

// alterantively:
data Foo {
  class Bar(x: Int)
  class Baz(y: String)
  object Quux
  object Bah
}

// also
data Foo { Bar(x: Int); Bax(y: String); Quux; Bah }
data Foo { class Bar(x: Int); class Bax(y: String); object Quux; object Bah }