sequence.scala

object Utils {

  import scala.concurrent.duration._
  import play.api.libs.concurrent.Promise
  import play.api.libs.iteratee.{ Enumerator, Iteratee }

  def sequence[A, B](seq: Seq[A])(f: A => Future[B]): Future[Seq[B]] = {
    val enumerator = Enumerator[A](seq: _*)
    val consummer = Iteratee.foldM[A, Seq[B]](Seq.empty[B]) {
      case (acc, i) => f(i).map(t => t +: acc)
    }
    enumerator.run(consummer)
  }
}