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.