rlm-rs: Instructions file for Claude Code

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

rlm_rs is a Rust crate built with modern tooling, strict type safety, and zero-cost abstractions.

Project Structure

src/
├── lib.rs           # Library entry point and public API
├── main.rs          # Binary entry point (optional)
├── error.rs         # Error types (if separated)
└── ...              # Additional modules

tests/
└── integration_test.rs  # Integration tests

benches/              # Benchmarks (with criterion)
examples/             # Example programs

Build Commands

This project uses Cargo as the build system.

# Build the project
cargo build

# Build with optimizations
cargo build --release

# Run tests
cargo test

# Run tests with output
cargo test -- --nocapture

# Run specific test
cargo test test_name

# Run benchmarks
cargo bench

# Run linting
cargo clippy --all-targets --all-features

# Format code
cargo fmt

# Check formatting
cargo fmt -- --check

# Generate documentation
cargo doc --open

# Check supply chain security
cargo deny check

# Run with MIRI (undefined behavior detection)
cargo +nightly miri test

# Run all checks (lint + format + test + doc + deny)
cargo fmt -- --check && cargo clippy --all-targets --all-features -- -D warnings && cargo test && cargo doc --no-deps && cargo deny check

Code Style Requirements

This project uses clippy with pedantic and nursery lints, and rustfmt for formatting.

Key Rules

• Line length: 100 characters
• Edition: 2024
• MSRV: 1.95
• Unsafe code: Forbidden unless explicitly justified
• Panics: Not allowed in library code (unwrap, expect, panic!)

Error Handling

Always use Result types for fallible operations. Never panic in library code:

// Good - Returns Result
pub fn parse(input: &str) -> Result<Value, ParseError> {
    if input.is_empty() {
        return Err(ParseError::EmptyInput);
    }
    // parsing logic
    Ok(value)
}

// Bad - Panics
pub fn parse(input: &str) -> Value {
    input.parse().unwrap() // Never do this in library code
}