coding-guidelines

# Rust Coding Guidelines (50 Core Rules) ## Naming (Rust-Specific) | Rule | Guideline | |------|-----------| | No `get_` prefix | `fn name()` not `fn get_name()` | | Iterator convention | `iter()` / `iter_mut()` / `into_iter()` | | Conversion naming | `as_` (cheap &), `to_` (expensive), `into_` (ownership) | | Static var prefix | `G_CONFIG` for `static`, no prefix for `const` | ## Data Types | Rule | Guideline | |------|-----------| | Use newtypes | `struct Email(String)` for domain semantics | | Prefer slice patterns | `if let [first, .., last] = slice` | | Pre-allocate | `Vec::with_capacity()`, `String::with_capacity()` | | Avoid Vec abuse | Use arrays for fixed sizes | ## Strings | Rule | Guideline | |------|-----------| | Prefer bytes | `s.bytes()` over `s.chars()` when ASCII | | Use `Cow<str>` | When might modify borrowed data | | Use `format!` | Over string concatenation with `+` | | Avoid nested iteration | `contains()` on string is O(n*m) | ## Error Handling | Rule | Guideline | |------|-----------| | Use `?` propagation | Not `try!()` macro | | `expect()` over `unwrap()` | When value guaranteed | | Assertions for invariants | `assert!` at function entry | ## Memory | Rule | Guideline | |------|-----------| | Meaningful lifetimes | `'src`, `'ctx` not just `'a` | | `try_borrow()` for RefCell | Avoid panic | | Shadowing for transformation | `let x = x.parse()?` | ## Concurrency | Rule | Guideline | |------|-----------| | Identify lock ordering | Prevent deadlocks | | Atomics for primitives | Not Mutex for bool/usize | | Choose memory order carefully | Relaxed/Acquire/Release/SeqCst | ## Async | Rule | Guideline | |------|-----------| | Sync for CPU-bound | Async is for I/O | | Don't hold locks across await | Use scoped guards | ## Macros | Rule | Guideline | |------|-----------| | Avoid unless necessary | Prefer functions/generics | | Follow Rust syntax | Macro input should look like Rust | ## Deprecated → Better | Deprecated | Better | Since | |------------|--------|-------| | `lazy_static!` | `std::sync::OnceLock` | 1.70 | | `once_cell::Lazy` | `std::sync::LazyLock` | 1.80 | | `std::sync::mpsc` | `crossbeam::channel` | - | | `std::sync::Mutex` | `parking_lot::Mutex` | - | | `failure`/`error-chain` | `thiserror`/`anyhow` | - | | `try!()` | `?` operator | 2018 | ## Quick Reference ``` Naming: snake_case (fn/var), CamelCase (type), SCREAMING_CASE (const) Format: rustfmt (just use it) Docs: /// for public items, //! for module docs Lint: #![warn(clippy::all)] ``` Claude knows Rust conventions well. These are the non-obvious Rust-specific rules.