Language servers frequently consume gigabytes of memory on modest codebases, turning developer machines into sluggish heaters. Rust Glancer reimagines this baseline by running a full language server protocol pipeline inside an envelope of under one hundred megabytes of RAM.
Created by the original author of rust-analyzer, the engine achieves this efficiency through structural persistence and aggressive type inference simplification. Instead of recalculating the entire syntax tree on every workspace change, it persists the index to disk. When an engineer restarts their editor, the LSP becomes operational immediately without triggering a redundant multi-minute re-indexing cycle.
Benchmarks demonstrate a baseline indexing time of six seconds on an older M1 machine, directly rivaling or beating heavyweight compilers while using a tiny fraction of their working set. It sacrifices macro expansion edge cases in exchange for instant code navigation, trait solving via Chalk, and reliable completion.
Developer tools do not need to consume all available resources to deliver rapid feedback.









