Box.scala

class Box[T](val value: T) {

  def map[B](f: T => B) = new Box(f(this.value))

  def flatMap[B](f: T => Box[B]) = f(this.value)

  def apply[B](f: Box[T => B]) = new Box(f.value(this.value))
}

println(new Box("cool").map((a:String) => a.toUpperCase).value)
println(new Box("cool").flatMap((a:String) => new Box(a.toUpperCase)).value)
println(new Box("cool").apply(new Box((a:String) => a.toUpperCase)).value)

println(new Box("cool")
  .map((a:String) => a.toUpperCase)
  .map((a:String) => a + " story!")
  .value)