For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt, and this page is available as Markdown at /reference/control.md.

Control

Asserts that a given condition is true.Executes a synchronous function and wraps the outcome in a Result, so callers can handle failure without try/catch.Executes an asynchronous function and wraps the outcome in a Result.Constructs a failure Result.Asserts that a given condition is true.Type guard that narrows a Result to Err.Type guard that narrows a Result to Ok.Constructs a success Result.Marks a code path you intend to implement later and throws if execution reaches it.Marks a code path as intentionally unsupported and throws if execution reaches it.Marks a code path as logically impossible and throws if execution reaches it.Extract the value from an Ok result, or throw on Err.