split a stream in many

Question

I'd like to know if there a elegant way to achieve something like that:

val l = Stream.from(1)

val parts = l.some_function(3)  //any number

parts.foreach( println(_) )

> 1,4,7,10... 
> 2,5,8,11...
> 3,6,9,12...

Actually I need such operation on Streams for parallelization - to split the data across multiple actors without loading the whole stuff into memory.

Answer 1

The answer from Split a scala list into n interleaving lists fully meets the conditions, a little bit modified to suit Streams:

def round[A](seq: Iterable[A], n: Int) = {
  (0 until n).map(i => seq.drop(i).sliding(1, n).flatten)
}
round(Stream.from(1),3).foreach(i => println(i.take(3).toList))
List(1, 4, 7)
List(2, 5, 8)
List(3, 6, 9)