reactive look-and-say sequence w/ RxScala

LookAndSay.scala

import rx.lang.scala.Observable
import rx.lang.scala.subjects.BehaviorSubject

object LookAndSay {

  def main(args: Array[String]) {
    val pipe = BehaviorSubject(Observable.just('1'))
    pipe.map(next).foreach(x => {
      x.doOnCompleted(println()).foreach(print(_))
      pipe.onNext(x)
    })
    readLine()
  }

  def next(cs: Observable[Char]): Observable[Char] =
    cs.scan ((0, ' ')) ((s, c) => if (s._2 != c) (1, c) else (s._1+1, c))
      .drop(1)
      .slidingBuffer(2,1)
      .filter(x => x.size == 1 || x(0)._2 != x(1)._2)
      .flatMap(x => Observable.from(x(0)._1.toString :+ x(0)._2))

}

http://en.wikipedia.org/wiki/Look-and-say_sequence