Using Scalactic Or and Validation

gistfile1.scala

scala> import org.scalactic._
import org.scalactic._

scala> def reasons(x: Int): Int Or ErrorMessage =
     |   for {
     |     y <- Good(x) filter { i => if (i > 0) Pass else Fail(s"$i was <= 0") }
     |     z <- Good(y / 2) filter { i => if (i > 1) Pass else Fail(s"$y / 2 was <= 1") }
     |   } yield z
reasons: (x: Int)org.scalactic.Or[Int,org.scalactic.ErrorMessage]

scala> (0 to 4) map reasons
res0: scala.collection.immutable.IndexedSeq[org.scalactic.Or[Int,org.scalactic.ErrorMessage]] =
  Vector(Bad(0 was <= 0), Bad(1 / 2 was <= 1), Bad(2 / 2 was <= 1), Bad(3 / 2 was <= 1), Good(2))