method 이름은 같은데 param, return 타입을 다르게 구현하기

case class GoogleRaw(content: String, crawlId: String)
case class NaverRaw(content: String)

case class GoogleParsed(sections: Seq[String], crawlId: String)
case class NaverParsed(sections: Seq[String])

trait Cralwer {
  type Raw
  type Parsed

  def fetch(url: String): Raw
  def parse(raw: Raw): Parsed
  def save(raw: Raw, parsed: Parsed): Int
}

object GoogleCrawler extends Cralwer {
  type Raw = GoogleRaw
  type Parsed = GoogleParsed

  override def fetch(url: String): GoogleRaw = GoogleRaw("g", "id123")

  override def parse(raw: GoogleRaw): GoogleParsed = GoogleParsed(Seq(raw.content), raw.crawlId)

  override def save(raw: GoogleRaw, parsed: GoogleParsed): Int = 1
}

object NaverCrawler extends Cralwer {
  type Raw = NaverRaw
  type Parsed = NaverParsed

  override def fetch(url: String): NaverRaw = NaverRaw("n")

  override def parse(raw: NaverRaw): NaverParsed = NaverParsed(Seq(raw.content))

  override def save(raw: NaverRaw, parsed: NaverParsed): Int = 2
}

@main def main(): Unit = {
//  val cralwer: Cralwer = GoogleCrawler
  val cralwer: Cralwer = NaverCrawler

  val content: cralwer.Raw = cralwer.fetch("http://www.some.com")
  val parsed: cralwer.Parsed = cralwer.parse(content)

  parsed match {
    case GoogleParsed(_, id)  => println(id)
    case NaverParsed(content) => println(content)
  }

  val savedCnt = cralwer.save(content, parsed)
  println(savedCnt)
}