Delimiters are spaces, so in principle, a space would already put you in the `ROUTE_URL` partition type. I don't think the partitioner should try to understand anything *inside* partitions, but simply divide the document in what makes sense ("sense" being the functionality we want to attach to partitions, such as completion proposals and auto-edits). Not a big deal right now, but when we'll have different behaviors for each partition, we might need to re-visit this case.