Interesting choice to reply to matklad, one of rust-analyzer's primary authors, to explain how it works.

Nah, it’s a totally valid question: I indeed didn’t clarify where incrementality starts to happen.

I slapped myself in the face.

Yeah, to clarify, memoization happens after parsing. So for syntax highlighting we have a situation where from-scratch parsing is faster than incremental typechecking.

Thanks for explaining and making rust-analyzer!