Scala: List[Future] to Future[List] disregarding failed futures

Question

I\'m looking for a way to convert an arbitrary length list of Futures to a Future of List. I\'m using Playframework, so ultimately, what I really want is a Future[Resu

Answer 1

You can also collect successful and unsuccessful results in different lists:

def safeSequence[A](futures: List[Future[A]]): Future[(List[Throwable], List[A])] = {
  futures.foldLeft(Future.successful((List.empty[Throwable], List.empty[A]))) { (flist, future) =>
    flist.flatMap { case (elist, alist) =>
      future
        .map { success => (elist, alist :+ success) }
        .recover { case error: Throwable => (elist :+ error, alist) }
    }
  }
}