State monad in scalaz

gistfile1.scala

scala> state[Int, Int](10)
res9: scalaz.State[Int,Int] = scalaz.package$State$$anon$1@3bbe242c

scala> res9.run(0)
res10: (Int, Int) = (0,10)

scala> res9 map (_ * 2)
res11: scalaz.StateT[scalaz.Id.Id,Int,Int] = scalaz.StateT$$anon$7@31a9253

scala> res11.run(0)
res12: (Int, Int) = (0,20)

scala> res9 flatMap {a => state(a * 3)}
res14: scalaz.StateT[scalaz.Id.Id,Int,Int] = scalaz.StateT$$anon$7@18ee131f

scala> res14.run(12)
res15: (Int, Int) = (12,30)

scala> for {
     |   r <- res14
     |   p <- state(r * 8)
     | } yield p
res19: scalaz.StateT[scalaz.Id.Id,Int,Int] = scalaz.StateT$$anon$7@5ef21bc4

scala> res19.run(0)
res20: (Int, Int) = (0,240)

scala>