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copied!<p>The signature of the normally-used <code>collect</code> on, say, <code>Seq</code>, is</p> <pre><code>collect[B](pf: PartialFunction[A,B]): Seq[B] </code></pre> <p>which is really a particular case of</p> <pre><code>collect[B, That](pf: PartialFunction[A,B])( implicit bf: CanBuildFrom[Seq[A], B, That] ): That </code></pre> <p>So if you use it in default mode, the answer is no, assuredly not: you get exactly one sequence out from it. If you follow <code>CanBuildFrom</code> through <code>Builder</code>, you see that it would be possible to make <code>That</code> actually be two sequences, but it would have no way of being told which sequence an item should go into, since the partial function can only say "yes, I belong" or "no, I do not belong".</p> <p>So what do you do if you want to have multiple conditions that result in your list being split into a bunch of different pieces? One way is to create an indicator function <code>A => Int</code>, where your <code>A</code> is mapped into a numbered class, and then use <code>groupBy</code>. For example:</p> <pre><code>def optionClass(a: Any) = a match { case None => 0 case Some(x) => 1 case _ => 2 } scala> List(None,3,Some(2),5,None).groupBy(optionClass) res11: scala.collection.immutable.Map[Int,List[Any]] = Map((2,List(3, 5)), (1,List(Some(2))), (0,List(None, None))) </code></pre> <p>Now you can look up your sub-lists by class (0, 1, and 2 in this case). Unfortunately, if you want to ignore some inputs, you still have to put them in a class (e.g. you probably don't care about the multiple copies of <code>None</code> in this case).</p>

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