case class updates

responses.scala

  sealed trait Response
  case object Right extends Response
  case object Wrong extends Response
  case object Skip  extends Response

  case class Responses(right: Long = 0, wrong: Long = 0, skip: Long = 0) {
    def apply(r: Response) = r match {
      case Right => right
      case Wrong => wrong
      case Skip  => skip
    }

    def updated(r: Response, v: Long) = r match {
      case Right => Responses(v,wrong,skip)
      case Wrong => Responses(right,v,skip)
      case Skip  => Responses(right,wrong,v)
    }

    def inc(r: Response) = r match {
      case Right => Responses(right+1,wrong,skip)
      case Wrong => Responses(right,wrong+1,skip)
      case Skip  => Responses(right,wrong,skip+1)
    }
  }