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    <p>Standard pattern-matching will always match on only exactly one case. You can get close to what you want by using the fact that patterns can be treated as partial functions (see the <a href="http://www.scala-lang.org/docu/files/ScalaReference.pdf" rel="nofollow noreferrer">Language Specification</a>, Section 8.5, <em>Pattern Matching Anonymous Functions</em>) and by defining your own matching operator, though:</p> <pre><code>class MatchAll[S](scrutinee : =&gt;S) { def matchAll[R](patterns : PartialFunction[S,R]*) : Seq[R] = { val evald : S = scrutinee patterns.flatMap(_.lift(evald)) } } implicit def anyToMatchAll[S](scrut : =&gt;S) : MatchAll[S] = new MatchAll[S](scrut) def testAll(x : Int) : Seq[String] = x matchAll ( { case 2 =&gt; "two" }, { case x if x % 2 == 0 =&gt; "even" }, { case x if x % 2 == 1 =&gt; "neither" } ) println(testAll(42).mkString(",")) // prints 'even' println(testAll(2).mkString(",")) // prints 'two,even' println(testAll(1).mkString(",")) // prints 'neither' </code></pre> <p>The syntax is slightly off the usual, but to me such a construction is still a witness to the power of Scala.</p> <p>Your example is now written as:</p> <pre><code>// prints both 'foo' and 'bar' "both" matchAll ( { case "both" | "foo" =&gt; println("foo") }, { case "both" | "bar" =&gt; println("bar") } ) </code></pre> <p>(<strong>Edit</strong> <a href="https://stackoverflow.com/users/257449/huynhjl">huynhjl</a> pointed out that he gave a frighteningly similar answer to <a href="https://stackoverflow.com/questions/6720205/idiomatic-way-to-convert-a-seqb">this question</a>.)</p>
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    1. COThis is an amazingly clean solution. Well done!
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    2. COThis reminds me of http://stackoverflow.com/questions/6720205/idiomatic-way-to-convert-a-seqb/6720659#6720659. What's the benefit of the by name `=> S`?
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    3. COWow. I had no idea this was there. Thanks for adding the link. I use the by name argument for the (unlikely) case someone would construct the MatchAll instance before using it, so that the potential effects resulting from the evaluation of the scrutinee appear in the right place.
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