The particulars of Rust make this a little more difficult, I think. There’s a certain tension between making your language more concise and adding useful redundancies, and Rust has generally gone to the “concise” side, with some redundancies that can make the tooling a little more painful. Like with imports.

  impl std::fmt::Display for Blah {
  }

If your language makes you qualify your imports (like above) then your LSP can, delightfully, still reliably do certain ops like renaming, even when chunks of your project aren’t parsing. But if you glob import std::fmt, and glob import something else, you are fucked. Display could come from anywhere (maybe from a module that has a parse error at the moment). I really appreciate languages where glob imports (or their equivalent) are either disallowed entirely or where typical code doesn’t use it.

Meanwhile, if you add a new file, there’s this little dance where you say:

  mod mycoolmod;

And then you create mycoolmod.rs. Or you do it the other way around. A little redundancy (the file exists and it is declared), that seems to just create a little friction in the LSP because mycoolmod doesn’t get a working LSP until it’s declared in the parent (you have to create both, and then you get a transient diagnostic that your module is unused for a while yet). A small issue, just another little bit of friction in the tooling of Rust that has nothing to do with the type system.