eglot VS rust-analyzer

Recently I stumbled upon this issue:

https://github.com/joaotavora/eglot/discussions/1127

I don't know enough about emacs and LSP to see the full picture, but it seems that both eglot's and corfu's maintainers, assumably very competent programmers, can't find a solution for this.

I only skimmed the thread. My understanding is that LSP dumps a long list of completion candidates at once and they can't decide a cache strategy that works well with existing code...?

It could be. There are unfixed issues with eglot and corfu, and sadly not a lot of willingness to investigate.

Eglot errors when I add new Python code blocks. The error disappears when I reconnect the language server, but the same happens again when I add a new code block. My "workaround" now is that before I start working on the .qmd file, I just add a bunch of Python code blocks (for which I also have a function) and then reconnect the language server again. This way I can start working for a while until I need to add more code blocks again.

This discussion has helped with some performance issues: https://github.com/joaotavora/eglot/discussions/993.

I guess eglot doesn't support it yet: https://github.com/joaotavora/eglot/pull/839

This is not by pure chance, João is the developer of the Eglot LSP client and the breadcrumbs from LSP-mode had been requested as a feature, but as far as I remember João thought rightfully that this could be an independent package, see https://github.com/joaotavora/eglot/discussions/988

A substantial section of the community is using corfu instead of company, but I wouldn't say company is out of date by any means. In emacs 29 eglot will be a built in, which might act as a replacement for lsp-mode depending on what functionality you need.

I am currently running emacs 29 (built from emacs-29 branch) which – according to https://github.com/joaotavora/eglot – should contain the latest eglot.

Yep. You can use flymake or flycheck for that in combination with eglot or lsp-mode.

See https://github.com/joaotavora/eglot#diagnostics

(I have reported this (that is, ElDoc missing docs for callable things at point, when Eglot is enabled) as an issue recently: First on GitHub-discussions https://github.com/joaotavora/eglot/discussions/1200, then on Debbugs https://debbugs.gnu.org/cgi/bugreport.cgi?bug=62687. But the threads are very long, so I don't recommend reading them.)

go build 3.62s user 0.76s system 171% cpu 2.545 total

I was looking forward to parallel front-end[4], but I have not seen any improvement for these small changes.

[1]: https://github.com/rust-lang/rust-analyzer

For example, intelephense can show diagnostics in real time, there is no need to save the file to get new diagnostics. But rust-analyzer, the language server for rust, can only update diagnostics after saving the file.

6. Rust Analyzer

The rust-analyzer readme suggests you go here for support request. But even there, you'll need to provide more details to get useful help.

For example: https://github.com/rust-lang/rust-analyzer/blob/master/docs/...

> If you create an LSP, it will work best in VS Code.

Any editor can work just as well as (or even better than) VS Code.

So, apparently the reason why rust-analyzer, the LSP server for Rust does not have persistent caching is because it would make "optimizing initial passes less important".

All I want to know is: Will it have a build configuration pulldown?

I am not a Rust dev. It surely looks great.

However, from what I understand it seems to supply just a parser separate from the Rust compiler (https://github.com/rust-lang/rust-analyzer/tree/master/crate...) trying to keep up with Rust‘s development. So, in principle, it could have been just another treesitter parser plugin, too.

So, again, the LSP framework does not directly provide any magical benefit over a static parsing framework. All the semantic analysis capabilities stem from a good parser.

rust-analyzer > manual > helix > binary > rustup component add rust-analyzer