breaking virtpatmat with skolems

virtpatmat_skolems.scala

// exploring skolems/existentials that stem from scrutinee.tpe/unapply-type-params,
// and how they break virtpatmat
object Test {
  object UnBounded {
    def unapply[A](xs: UnBounded[A]): Option[A] = Some(xs.el)
  }
  class UnBounded[T](val el: T)

  object Bounded {
    def unapply[A <: Ord[A]](xs: Bounded[A]): Option[A] = Some(xs.el)
  }
  class Bounded[T <: Ord[T]](val el: T)
  class Ord[T]
  class IntO extends Ord[IntO]

  object Exist {
    def unapply(xs: Exist[_]): Option[_] = Some(xs.el)
  }
  class Exist[T](val el: T)

  val s: PartialFunction[Any, Any] = {
    case UnBounded(x) => x
    case Exist(x) => x
  }

  abstract class I {
    type x <: Ord[x]
    type B = Bounded[x]
  }
  val t :  PartialFunction[I#B, Any] = {
    case Bounded(x) => x
  }
}