[scala] unapplyメモ

extractorとしてのunapplyのサンプルコードメモ．

Message.scala - メッセージ　コンパニオンクラス

package tanuneko.ui2

class Message(val msg:String) {

  def this() = this(msg = "")

  override def toString():String = {
    s"msg:${msg}"
  }

  def show(): Unit = {
    println(msg)
  }

}

object Message {

  def apply(): Unit = new Message()
  def apply(msg:String) = new Message(msg)
  def unapply(res:Message) = Some(res.msg + "dayon")

}

MessageTestSpec.scala - メッセージspec2テスト

package tanuneko.test

import tanuneko.ui2.Message
import org.specs2._

class MessageTestSpec extends mutable.Specification {
  "Message unapply" should {
    "return its msg field" in {
      val resp = Message("nyanchan")
      var isOk = resp match {
        case Message(x) if x == "nyanchandayon" => true
        case _ => false
      }
      isOk must beTrue
    }
  }
}