Futures.scala

def parallelPaper(lines: List[String]): Future[Int] = {
  val computingCounts: List[Future[Int]] = lines.map(line => parallelCompute(line)) 
  val futureComputedCounts: Future[List[Int]] = Future.sequence(computingLines)
  val resultFuture: Future[Int] = 
    futureComputedCounts.map { counts =>
      val accumulatorInitialValue = 0
      counts.foldLeft(accumulatorInitialValue)((accumulator, nextCount) => accumulator + nextCount)
    }
 
  resultFuture
}