Clear Rust

Write plain Rust: make behavior, ownership, failure, and control flow easy to see.

Use these design defaults within the repository's contracts, MSRV, conventions, and measured performance requirements. For reviews or diagnosis, assess the code without rewriting it unless requested. Preserve already-clear choices.

Loops and iterators, borrowing and cloning, enums and traits, and sync and async are contextual choices: favor the form whose behavior is easiest to trace.