title: Haskell GHCi prints lazy sequence but Scala REPL doesn't
body: <p>I would to print out a stream of numbers but the following code only prints out the first number in the sequence:</p>
  
  <pre><code>for ( n &lt;- Stream.from(2) if n % 2 == 0 ) yield println(n)
  2
  res4: scala.collection.immutable.Stream[Unit] = Stream((), ?)
  </code></pre>
  
  <p>In Haskell the following <em>keeps</em> printing out numbers until interrupted and I would like similar behaviour in Scala:</p>
  
  <pre><code>naturals = [1..]
  [n | n &lt;- naturals, even n]
  [2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50,52,54,56,58,
  </code></pre>