http://stackoverflow.com/questions/14789521/object-cross-references-and-initialization-order

output

$ scalac x.scala
$ scala Test
List(Test$B$@4ce32802, Test$C$@5557c2bd)
List(Test$A$@5ef4f44a, Test$D$@23d256fa)
List(Test$A$@5ef4f44a, Test$B$@4ce32802)
List(Test$C$@5557c2bd, Test$B$@4ce32802, Test$A$@5ef4f44a)
List(Test$B$@4ce32802, Test$A$@5ef4f44a, Test$B$@4ce32802)

x.scala

object Test extends App {
  abstract class SuperClass (cs: => Seq[SuperClass]) {
    def init {
      println(cs)
    }
  }

  object A extends SuperClass(Seq(B, C))
  object B extends SuperClass(Seq(A, D))
  object C extends SuperClass(Seq(A, B))
  object D extends SuperClass(Seq(C, B, A))
  object E extends SuperClass(Seq(B, A, B))

  object Initializer {
    def init {
      A.init
      B.init
      C.init
      D.init
      E.init
    }
  }

  Initializer.init
}