無限Streamのgrouped

gistfile1.scala

scala> val s: Stream[Int] = Stream.continually {1}
s: Stream[Int] = Stream(1, ?)

scala> val i = s.grouped(3)
i: Iterator[scala.collection.immutable.Stream[Int]] = non-empty iterator

scala> i take 5 foreach println
Stream(1, ?)
Stream(1, ?)
Stream(1, ?)
Stream(1, ?)
Stream(1, ?)

scala> i take 5 foreach {x => x foreach println}
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

scala>