gistfile1.scala

@tailrec
  def extractor[T](resultSet: ResultSet,
              result: scala.collection.mutable.Builder[T, Vector[T]] = Vector.newBuilder[T])( process: ResultSet => T ): Vector[T] = {
    if (!resultSet.next) result.result()
    else {
      val value = process(resultSet)
      extractor(resultSet, result += value)(process)
    }
  }