LGTM, but I'll let others take a look too in case I missed something. I'll also need to update the 2.0 grammar sometime soon after this lands..

I actually want to change some of the whitespace rules now that I look at it. It's missing whitespace after =>, I think whitespace should be allowed in more places, and I want to allow newlines in all/most whitespace if that's okay with you.

I'm fine with that

Should this be a breaking change? Or just make it non-normative until a new major release?

I tried to split the patch but everything got sent at once so the commit message is a bit misleading, but I:

• added support for newlines to any whitespace
• added some places where whitespace is allowed (around most if not all operators)
• added the two accessors unique to mappings (props(), values())
• added a notice that this grammar is not normative for now

I think we should just make KQL 2.0.0 and be done with it, instead of trying to incrementally improve 1.0, but that's just me. wdyt?

That's fine with me too but I think that should be after/together with KDL 2.0.0, not before (given the pending changes to identifiers). I guess KQL 2.0.0 would also include the new selector operators? I'm excited for those.

Can you update this PR to target kdl-v2 instead, then? You'll have to rebase, but idk if you'll run into conflicts.

Nevermind, that didn't really work I think. I'll rebase locally and force-push.

Then I've removed the part of the grammar concerning the map operator too, since that was removed.