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unapplySeq is useful when number of subvalues ISN'T fixed #188

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Merged
merged 1 commit into from
May 18, 2020
Merged

unapplySeq is useful when number of subvalues ISN'T fixed #188

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2 changes: 1 addition & 1 deletion src/main/scala/stdlib/Extractors.scala
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Expand Up @@ -59,7 +59,7 @@ object Extractors extends AnyFlatSpec with Matchers with org.scalaexercises.defi
* - If it returns a single sub-value of type `T`, return a `Option[T]`
* - If you want to return several sub-values `T1,...,Tn`, group them in an optional tuple `Option[(T1,...,Tn)]`.
*
* Sometimes, the number of sub-values is fixed and we would like to return a sequence. For this reason, you can also define patterns through `unapplySeq`. The last sub-value type `Tn` has to be `Seq[S]`. This mechanism is used for instance in pattern `case List(x1, ..., xn)`.
* Sometimes, the number of sub-values isn't fixed and we would like to return a sequence. For this reason, you can also define patterns through `unapplySeq`. The last sub-value type `Tn` has to be `Seq[S]`. This mechanism is used for instance in pattern `case List(x1, ..., xn)`.
*
* When you create a case class, it automatically can be used with pattern matching since it has an extractor:
*
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