As a newcomer to the Scala language, I find [this section](https://github.com/scala/docs.scala-lang/blob/main/_overviews/scala3-book/taste-control-structures.md?plain=1#L375-L385) difficult to follow. It would help if `Person` and `name`were defined somewhere to be able to compile at least but it's not at all clear what is going on to me. Is anyone able to shed some light, happy to improve the docs myself once I understand what's trying to be demonstrated here.