Claiming "fast" implies that performance is a project goal, possibly even tracked over time as a metric, and that there's probably a comparison deeper in the RE

Claiming "fast" implies that performance is a project goal, possibly even tracked over time as a metric, and that there's probably a comparison deeper in the README or elsewhere. It probably also means that when it comes to tradeoffs (compile time, code size, binary size, ergonomics, maybe even strictness/correctness), runtime speed is the preferred option.