¶Salsa persistence
Salsa was originally developed for an LSP language server, and was inspired by a similar mechanism in rustc. As such, it focuses on in-memory persistence and reuse of data.
Red Knot would very much like to have salsa query results persist across multiple invocations, so save on redundant work when type-checking a new snapshot of code that is being actively edited locally.
salsa#10 is the upstream issue tracking this work.