scala - 组合多个提取器对象以在一个匹配语句中使用

Question

是否可以在一个 match 语句中运行多个提取器？

object CoolStuff {
  def unapply(thing: Thing): Option[SomeInfo] = ...
}
object NeatStuff {
  def unapply(thing: Thing): Option[OtherInfo] = ...
}

// is there some syntax similar to this?
thing match {
  case t @ CoolStuff(someInfo) @ NeatStuff(otherInfo) => process(someInfo, otherInfo)
  case _ => // neither Cool nor Neat
}

这里的目的是有两个提取器，我不必做这样的事情:

object CoolNeatStuff {
  def unapply(thing: Thing): Option[(SomeInfo, OtherInfo)] = thing match {
    case CoolStuff(someInfo) => thing match {
      case NeatStuff(otherInfo) => Some(someInfo -> otherInfo)
      case _ => None // Cool, but not Neat
    case _ => None// neither Cool nor Neat
  }
}

Answer 1

可以尝试

object ~ {
  def unapply[T](that: T): Option[(T,T)] = Some(that -> that)
}

def too(t: Thing) = t match {
  case CoolStuff(a) ~ NeatStuff(b) => ???
}