Converting Map[String, Seq[Int]] to Seq[Seq[Int]]
<p>I am trying to convert data that looks like this:</p>

<pre><code>val inputData =
  Seq(("STUDY1", "Follow-up", 1),
    ("STUDY1", "Off Study", 2),
    ("STUDY1", "Screening", 3),
    ("STUDY1", "Treatment", 4),
    ("STUDY2", "Follow-up", 5),
    ("STUDY2", "Off Study", 6),
    ("STUDY2", "Screening", 7),
    ("STUDY2", "Treatment", 8));
</code></pre>

<p>into data that looks like this:</p>

<pre><code>val desiredData =
  Seq(Seq(1,2,3,4),
    Seq(5,6,7,8));
</code></pre>

<p>The closest that I've gotten is with this:</p>

<pre><code>val result: Map[String, Seq[Int]] =
  data.groupBy(i =&gt; i._1)
    .mapValues(j =&gt; j.map(k =&gt; k._3))
    .mapValues(_.toArray)

result.values.toSeq
</code></pre>

<p>This yields:</p>

<pre><code>res0: Seq[Seq[Int]] = Stream(WrappedArray(1, 2, 3, 4), ?)
</code></pre>

<p>That last question mark is throwing me for a loop.</p>

<p><strong>EDIT</strong>
Future internet travelers who land here: my code actually <em>did</em> work ... my confusion stemmed from understanding what the <code>?</code> was all about. Answers from folks down below helped me see that <code>mapValues</code> did lazy evaluation, and that the <code>?</code> simply implies that.</p>