rust

name	Rust
description	Rust development patterns, project setup, CLI/TUI applications, error handling, and system integration

Rust Development

This skill covers Rust development with two specialized reference documents:

When Starting a New Project

Use Rust-Project-Setup.md for:

• Creating new Rust CLI/TUI applications from scratch
• Cargo.toml setup and dependency selection
• Module structure and organization
• System dependency documentation (ALSA, X11, OpenGL, etc.)
• Configuration with serde/toml
• README and documentation templates
• Step-by-step implementation workflow

When Writing Code

Use Rust-Patterns.md for:

• Trait-based abstractions for swappable implementations
• Typestate pattern for security-sensitive state machines (compile-time state enforcement)
• Error handling (anyhow vs thiserror)
• CLI argument parsing with clap
• Structured logging with tracing
• Frame timing and performance monitoring
• Linux device I/O (v4l2, video processing)
• Color space conversion (RGB to YUYV)
• Testing patterns with mocks
• Defensive programming patterns

Quick Reference

Error Handling Decision

Is this a library?
├─ Yes → Use thiserror for typed errors
└─ No (application) → Use anyhow with .context()

State Machine Decision

Is this security-sensitive? (auth, crypto, transactions)
├─ Yes → Use TYPESTATE pattern (compile-time enforcement)
│        - State encoded in type system
│        - Invalid transitions = compile errors
│        - Methods only exist for valid states
└─ No → Runtime enums are fine
         - UI state, display modes
         - States that need runtime inspection

Common Dependencies

Need	Crate	Notes
Error handling (app)	anyhow	Flexible, ergonomic
Error handling (lib)	thiserror	Typed errors
CLI parsing	clap v4	Use derive feature
TUI framework	ratatui	With crossterm
Configuration	serde + toml	Standard approach
Async runtime	tokio	Most popular
HTTP client	reqwest	High-level, async
Logging	tracing	Structured logging

Cargo Commands

cargo check          # Fast compilation check
cargo build          # Debug build
cargo build --release # Optimized build
cargo test           # Run tests
cargo clippy         # Lint code
cargo fmt            # Format code
cargo doc --open     # Generate docs

Cargo.lock Decision

• Applications/Binaries: Commit Cargo.lock (reproducible builds)
• Libraries: Don't commit (let downstream decide versions)