filter.scala

val l = List(Success(true), Success(false), Failure(new Exception("a")))
val good = l.filter { result: Validation[Exception, Boolean] =>
  result match {
    case Success(r) => r
    case Failure(_) => false
  }
}
// List(Success(true))
val bad = good.flatMap { r =>
  r match {
    case Failure(m) => Some(m)
    case _ => None
  }
}
// always empty