Scala Nil equivalent for Set
scala, scala-collections
Solution
`Set.empty` is that set; although you can't get at it directly, it turns out that it is just a private object in the `Set` companion object (called, obviously enough, `EmptySet`). All that `Set.empty` does is return that set with a cast to the correct type.
It is done this way, instead of with `Nil`, because sets are invariant in their parameters. `Nil` is `List[Nothing]()`, but you couldn't add anything to a `Set[Nothing]()`.
If you need to specify the type of your empty set, you can use e.g. `Set.empty[String]`.
Problem
Is there an equivalent of `Nil` for `Set` in scala? I tried using `Nil` as a value for `Set`, but I got an error (expected since the type of `Nil` is `List`) Thanks