Declaration of a wrap function using Scala.

wrapFunction.scala

  type Text = Option[String]
  case class ColumnWidth(width: Int)

  sealed trait WrapError
  case class InvalidText(text: Text) extends WrapError
  case class InvalidColumnWidth(width: ColumnWidth) extends WrapError

  def wrap(text: Text, width: ColumnWidth): Either[WrapError, Text] = ???

  def foo(): Unit = {
    val text = Some("Hello!")
    val columnWidth = ColumnWidth(1)
    val result = wrap(text, columnWidth)
    result match {
      case Left(InvalidText(text)) => ???
      case Left(InvalidColumnWidth(width)) => ???
      case Right(Some(text)) => ???
      case _ => ???
    }
  }