import { SubscriptionLike } from './subscriptions.js';
export declare function firstValueFrom<T>(iterable: AsyncIterable<T>): Promise<T>;
export type EventTargetAsyncIterableOverflow = 'preserve' | 'drop' | 'error';
export interface EventTargetAsyncIterableOptions {
    signal?: AbortSignal;
    overflow?: EventTargetAsyncIterableOverflow;
    highWaterMark?: number;
}
export declare function fromEvent<E extends Event = Event>(target: EventTarget, type: string, options?: EventTargetAsyncIterableOptions): AsyncIterable<E>;
export interface AsyncIterableObserver<E> {
    next(value: E): void | Promise<void>;
    error?(error: unknown): void | Promise<void>;
    complete?(): void | Promise<void>;
}
export declare function subscribe<E>(stream: AsyncIterable<E>, observer: AsyncIterableObserver<E>): SubscriptionLike;