Monad for input generator in fp in scala

gistfile1.scala

trait Runnable[A] {
  def run: A
}

object Delay {
  def apply[A](a: => A) = new Runnable[A] {
    def run: A = a
  }

  def map[A, B](r: Runnable[A])(f: A => B): Runnable[B]  = new Runnable[B] {
    def run = f(r.run)
  }

  def flatMap[A, B](r: Runnable[A])(f: A => Runnable[B]): Runnable[B]  = new Runnable[B] {
    def run = f(r.run).run
  }

  val monad: Monad[Runnable] = new Monad[Runnable] {
    def flatMap[A, B](ma: Runnable[A])(f: (A) => Runnable[B]) = Delay.flatMap(ma)(f)

    override def map[A, B](ma: Runnable[A])(f: (A) => B) = Delay.map(ma)(f)

    def unit[A](a: => A) = Delay(a)
  }

}

//where you can run something like

object RunIO {
  def main(args: Array[String]) {
    val F = IO.monad[Runnable]
    import F._
    val s = sequence(List.fill(10000)(IO {math.random}).toList)
    println(IO.run(Delay.monad)(s).run)
  }
}