IsHListOfFutures object

IsHListOfFuturesObject.scala

object IsHListOfFutures {
    def apply[In <: HList, Out <: HList](implicit isHzippable: IsHListOfFutures[In, Out]): IsHListOfFutures[In, Out] = isHzippable

    implicit object HNilIsListOfFutures extends IsHListOfFutures[HNil, HNil] {
      override def hsequence(l : HNil)(implicit ec: ExecutionContext): Future[HNil] = Future.successful(HNil)
    }

    implicit def hconsIsHListOfFutures[H, In <: HList, Out <: HList]
         (implicit ev: IsHListOfFutures[In, Out]): IsHListOfFutures[Future[H] :: In, H :: Out] = new IsHListOfFutures[Future[H] :: In, H :: Out] {

      override def hsequence(l : Future[H] :: In)(implicit ec: ExecutionContext): Future[H :: Out] = {
        val head = l.head
        val tail = l.tail
        head.flatMap(h => ev.hsequence(tail).map(h :: _))
      }
    }

}