VecHlist.scala

VecHlist.scala

final object F {
  type HList //<: Product with Serializable
  type HNil <: HList
  type #:[+H, +T <: HList] <: HList

  implicit class HListBuilder[T <: HList](h: T) {
    def #:[H](a: H): H #: T = F.#:(a, h)
  }

  object #: {

    def unapply[H, T <: HList](h: H #: T): Option[(H, T)] = {
      val v = h.asInstanceOf[Vector[Any]]
      val head = v.head.asInstanceOf[H]
      val tail = v.tail.asInstanceOf[T]
      Option((head, tail))
    }

    def apply[H, T <: HList](h: H, t: T): H #: T =
      (h +: t.asInstanceOf[Vector[Any]])
        .asInstanceOf[H #: T]
  }

  val HNil: HNil = Vector().asInstanceOf[HNil]
}