very cool. I'm writing a compiler and language myself and I was on the fence about anonymous structs / tuples vs multiple returns, and seeing multiple returns in your examples nudged me that way.

I'm also influenced by Lua and I picked it up in your grammar right away : )

It's a bit of pain to implement in some cases, but worth it :)

Let me know, if you have questions or need hints where to find some relevant details in my code.