Score.scala

sealed trait Score {
  def isEmpty = this match {
    case SetScore(_, _) => false
    case NoScore => true
  }

  def isDefined = !isEmpty

  def toOption: Option[(Int, Int)] = this match {
     case NoScore => None
     case SetScore(home, away) => Some(home -> away)
  }
}

case object NoScore extends Score

case class SetScore(home: Int, away: Int) extends Score