Limitations

Rust Glancer is incomplete, and has a bunch of quirks that are worth knowing about.

Ultimate advice

If something unexpected happens: you start getting a lot of errors, index is messed up, LSP stops responding, etc:

• Try hitting ctrl/cmd+shift+P and sending Rust Glancer: Reindex workspace command.
• Try restarting the server: click on Rust Glancer on the bottom left of VS Code.
• If that doesn’t help, stop the editor, remove target/rust_glancer, and start again.

If you know how to reproduce the issue, it would be great if you also report it.

It shouldn’t happen often, but you know how it is with young software. I intentionally don’t implement any sophisticated recovery mechanisms: the idea is that the LSP should never fail, so when it does, it has to be loud. So if you meet a crash or indexing issue – sorry, but I hope that it will help us build a very reliable project long term.

Dirty buffers

Frozen workspace analysis can work on each keystroke, and it is actually usable, but it falls into a category that is workable but annoying enough to drive one insane. So to mitigate that, dirty buffers use partial analysis: we recompute the bodies that were affected, and we perform a somewhat “shallow” analysis.

It means that we can infer types as you type inside of the function, the completions for already known structures/functions/traits will work, but we cannot see new items. If you type the following without saving:

#![allow(unused)]
fn main() {
struct FooBar;

impl Foo$
}

you will not see FooBar in completions, because adding structure to analysis will require doing a lot of extra work. Similarly, we cannot add imports to the scope as you type, so the HashMap will not be suggested if you will type the following without saving:

#![allow(unused)]
fn main() {
use std::collections::HashMap;

fn foo(h: HashMa$)
}

So it’s important to obtain a mental model where you need to save whenever you add something meaningful – struct, trait, import, function.

It might take a bit of time to adjust, but if your flow wasn’t like this already, I can promise that it might feel pretty natural after a bit of time.