Blogger - Scalaz Motivation - 15

val tree: Tree[String] =
  Node("c",
    Node("b",
      Node("a", Empty(), Empty()),
      Node("a",
        Node("r", Empty(), Empty()),
        Empty()
      )
    ),
    Node("d",
      Node("a", Empty(), Empty()),
      Node("b",
        Node("a", Empty(), Empty()),
        Node("r",
          Empty(),
          Node("a", Empty(), Empty())
        )
      )
    )
  )

p(sum(tree)) // prints ###> abracadabra