SKILL.md
$2b
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.