Kleisli problems

gistfile1.scala

object KleisliValidation extends App {
  import scalaz._
  import Scalaz._
  import scala.util.control.Exception._

   implicit def vm = Validation.validationMonad[String]

  type EValidation[+T] = Validation[String, T]
  
  def toDouble(s: String): EValidation[Double] = allCatch.either(s.toDouble).fold(_.toString.fail, _.success)
  def sqrt(d: Double): EValidation[Double] = if (d >= 0) math.sqrt(d).success else "sqrt(%s) is too complex for me".format(d).fail
  
  val composed = Kleisli(toDouble) >==> sqrt 
  
  println(composed("2"))
  println(composed("-2"))
  println(composed("hi"))
}