ff_vs_shark.scala

type ErrorOr[A] = Either[String, A]

def errors(error: String): () => ErrorOr[Int] = () => {
  println(s"running $error")
  Left(error)
}

scala> val item1 = errors("error1")
item1: () => ErrorOr[Int] = $$Lambda$4361/1034150118@23f4a773

scala> val item2 = errors("error2")
item2: () => ErrorOr[Int] = $$Lambda$4361/1034150118@7c691bb6

scala> item1() >> item2()
running error1 //only runs item1
res5: ErrorOr[Int] = Left(error1)

scala> item1() *> item2() 
running error1 //runs item1
running error2 //runs item2
res6: ErrorOr[Int] = Left(error1) //only uses output from item on the right (item2)