> So you're not supposed to tell people where errors occur in Scala?

You're supposed to use the types `Option` and `Either` or if you're into scalaz then \/ (http://eed3si9n.com/learning-scalaz/Either.html) and Validation (http://eed3si9n.com/learning-scalaz/Validation.html). Throwing exceptions is a childish way to handle errors in FP.