score:4
Accepted answer
This appears to be a bug in the library. Do you want to file the bug or shall I?
scala> Seq.empty match {case Seq() => "yup"; case _ => "nope"}
res0: java.lang.String = yup
scala> Seq() match {case Seq.empty => "yup"; case _ => "nope"}
res1: java.lang.String = yup
scala> ("" : Seq[Char]) match {case Seq() => "yup"; case _ => "nope"}
res2: java.lang.String = yup
scala> ("" : Seq[Char]) match {case Seq.empty => "yup"; case _ => "nope"}
res3: java.lang.String = nope
score:0
In matching the unapply or unapplySeq functions are used, not apply as you seem to believe.
Source: stackoverflow.com
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