What Iterator.iterate should have been.

gistfile1.scala

object Bah {
    def iterate[T](t: T)(f: T => Option[T]): Iterator[T] = new Iterator {
        var next = Some(t)
        override def hasNext = next.isDefined
        override def next = {
            val result = next.get
            next = f(result)
            result
        }
    }
}