小编Jun*_*Jun的帖子

// Start writing your ScalaFiddle code here
sealed trait DSL[A]{
  // def run(): A ={
  //   this match {
  //     case GetLength(something) =>
  //       something.length
  //     case ShowResult(number) =>
  //       s"the length is $number"
  //   }
  // }
}

case class GetLength(something: String) extends DSL[Int]
case class ShowResult(number: Int) extends DSL[String]

def run[A](fa:DSL[A]): A ={
  fa match {
    case GetLength(something) =>
      something.length
    case ShowResult(number) =>
      s"the length is $number"
  }
}

val dslGetLength = GetLength("123456789")
val length = run(dslGetLength)
val …