This can be done pretty straightforwardly with the help of some of the Enumeratee
combinators:
import play.api.libs.iteratee._
def batch[A](n: Int): Enumeratee[A, List[A]] = Enumeratee.grouped(
Enumeratee.take(n) &>> Iteratee.getChunks[A]
)
We can then use this enumeratee to transform any enumerator into a new enumerator of lists:
val intsEnumerator = Enumerator(1 to 40: _*)
intsEnumerator.through(batch(7)).run(Iteratee.foreach(println))
This will print the following:
List(1, 2, 3, 4, 5, 6, 7)
List(8, 9, 10, 11, 12, 13, 14)
List(15, 16, 17, 18, 19, 20, 21)
List(22, 23, 24, 25, 26, 27, 28)
List(29, 30, 31, 32, 33, 34, 35)
List(36, 37, 38, 39, 40)
As expected.