export declare class AbortError extends Error {
    constructor(signal: AbortSignal);
}
/**
 * Abortable async iteration over a {@link ReadableStream}. Reads the source
 * reader directly and yields each chunk, so the consumer's `for await` drives a
 * single read loop with no intermediate stream or per-chunk enqueue.
 *
 * Unlike `stream.pipeThrough(..., { signal })`, this explicitly cancels the
 * source reader on abort or early `break`, propagating HTTP-client disconnects
 * and watchdog timeouts to the backend request instead of only stopping the
 * local consumer. On abort it throws {@link AbortError}; the lock is released
 * on completion, abort, throw, or early exit. The source is cancelled only on
 * abort or early exit — never on natural EOF.
 */
export declare function abortableSource<T>(stream: ReadableStream<T>, signal?: AbortSignal): AsyncGenerator<T>;
/**
 * Runs a promise-returning function (`pr`). If the given AbortSignal is aborted before or during
 * execution, the promise is rejected with a standard error.
 *
 * @param signal - Optional AbortSignal to cancel the operation
 * @param pr - Function returning a promise to run
 * @returns Promise resolving as `pr` would, or rejecting on abort
 */
export declare function untilAborted<T>(signal: AbortSignal | undefined | null, pr: Promise<T> | (() => Promise<T>)): Promise<T>;
/**
 * Memoizes a function with no arguments, calling it once and caching the result.
 *
 * @param fn - Function to be called once
 * @returns A function that returns the cached result of `fn`
 */
export declare function once<T>(fn: () => T): () => T;