GoKawiilI want to present a project that I've been working on for the past 4 months: an alternative Rust LSP implementation that is built with a focus on low memory usage.
It has two main features:
It can use very little memory (target <100mb for reasonable projects). There are caveats, these are described below.
It allows immediate indexing after restart: if your project was indexed, restarting the editor will not require re-indexing.
Your browser does not support embedded videos. You can download the recording instead.
Note: throughout this video, the used RAM remained under 100mb
These features make Rust Glancer suitable for the older computers: I have tested it on my old MacBook Pro M1 2020 with 8GB RAM, and it was pretty good.
Machine LSP Base indexing (engine usable) Full indexing MacBook Pro M4 Max, 36GB (2025) Rust Glancer 5 seconds 8 seconds MacBook Pro M4 Max, 36GB (2025) rust-analyzer 6 seconds 13 seconds MacBook Pro M1, 8GB (2020) Rust Glancer 6 seconds 9 seconds MacBook Pro M1, 8GB (2020) rust-analyzer 7 seconds 14 seconds
As you can imagine, 4 months is not a lot of time for a project as big as a Rust LSP. Rust Glancer is not a complete LSP yet, it has a lot of missing functionality, it has some known bugs, and it has a lot of things I want to improve.
At the same time, it is already pretty capable: it has a full indexing pipeline with type inference and a trait solver (chalk), most of the "normal" Rust syntax is supported, and most of the "normal" LSP actions do work as well: goto definition, hover, inlay hints, completions, you name it.
... continue reading