/**
 * Converts a function into a WebWorker URL object that can be passed into
 * thread(). Note that `fn` has to be a single function with no external
 * references or bindings, so that it can be stringified using .toString().
 */
export declare function functionToWorker(fn: () => unknown): string;
/**
 * Creates a new web worker, posts it a serializable data object, and returns
 * when the worker responds (or after a fixed timeout).
 */
export declare function thread<T = unknown>(url: string | URL, data: unknown, timeout?: number): Promise<T>;