Comment by panstromek

> GHC currently needs to parse+typecheck+codegen a file before it can process other files that import it. Codegen is slow. Thus, there's currently demand split compilation into "stages", so that the next file can be typechecked after its imports have been just typechecked (not codegenned).

> I would also enjoy if recompilation avoidance were to happen at the function level, not the file level.

This sounds like Rust is already doing a lot more incremental then GHC then. Rustc only needs to parse, expand macros and do name resolution. Everything else is incremental after that, on a very granular level.