这个Scala代码可以使用更少的内存吗？

import scala.collection.immutable._

object SetTest extends App {
  def time[a](f: => a): (a,Double) = {
    val start = System.nanoTime()
    val result: a = f
    val end = System.nanoTime()
    (result,1e-9*(end-start))
  }

  for (n <- List(1000000,10000000)) {
    println("n = %d".format(n))
    val (s2,t2) = time((Set() ++ (1 to n)).sum)
    println("sum %d,time %g".format(s2,t2))
  }
}

编译和运行产生

tile:scalafab% scala SetTest
n = 1000000
sum 1784293664,time 0.982045
n = 10000000
Exception in thread "Poller SunPKCS11-Darwin" java.lang.OutOfMemoryError: Java heap space
...

即,Scala无法在具有8 GB内存的计算机上表示一组1000万个Int.这是预期的行为吗？有没有办法减少内存占用？