Rust Compass

Experimental.
The extension is in alpha.

Contextual Rust guidance for VS Code. Get explanations from official documentation while you code.

Overview

Why

You know Rust syntax and you've done the tutorials. But in a real project, you want to make good decisions while staying in flow and sometimes you just need a quick reminder of what .iter() vs .into_iter() actually does... again.

• .iter() or .into_iter()?
• Do I need .peekable() here?
• Is .unwrap() okay here or should I handle the error?

Rust Compass answers these questions right in your editor, pulling explanations from official Rust documentation with examples showing when to use what—or just explains a concept so you can make a better decision.

Features

Pattern Detection — Recognizes common Rust patterns in your code: iterators, error handling, ownership, and more.

Hover Hints — Hover over detected patterns for a quick explanation and link to details.

Learn Panel — Click "Learn more" to open a sidebar with:

• Beginner-friendly explanation (simplified via Copilot)
• Official documentation from docs.rust-lang.org
• Comparison of related methods (e.g., all the ways to iterate)

Note: The beginner-friendly explanation requires GitHub Copilot for simplification. Without it, you'll still get the official documentation.

Bulb — Quick fixes via the lightbulb menu when improvements are available.

Settings

Commands

Open the command palette (Cmd+Shift+P / Ctrl+Shift+P):

• Rust Compass: Show Hint Panel
• Rust Compass: Toggle Hints
• Rust Compass: Set Project Context

How It Works

1. Rules in rules/*.json define patterns to detect (regex) and metadata
2. When you open a Rust file, the extension scans for matches
3. Hover triggers show inline hints
4. "Learn more" fetches the official docs and optionally simplifies them using VS Code's language model API

Adding Rules

Create or edit files in rules/. Each rule needs:

{
  "id": "iterator-collect",
  "pattern": "\\.collect\\s*[<:(]",
  "title": "Collecting an Iterator",
  "rustTerm": "Iterator::collect()",
  "explanation": "Transforms an iterator into a collection.",
  "example": "let v: Vec<_> = iter.collect();",
  "officialDoc": "https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.collect",
  "confidence": 0.8,
  "contexts": ["general"]
}

License

MIT