import { ObserverCbType, Subscription } from "./Subscription";
import { SubscriptionObserver } from "./SubscriptionObserver";
export declare type NoArgsWithoutReturnFunctionType = () => void;
export declare type SubscriberCbType<T> = (subscribeObserver: SubscriptionObserver<T>) => NoArgsWithoutReturnFunctionType | void;
export declare class Observable<T> {
    private _subscriberCb;
    constructor(subscriberCb: SubscriberCbType<T>);
    subscribe(observerCb: ((val?: T) => void) | ObserverCbType<T>): Subscription<T>;
    /** 创建一个 订阅，同时与 Promise 关联 */
    forEach(nextResolveCb: (value?: T, cb?: () => void) => void): Promise<void>;
    /**
     * filter: 建立两个订阅，中间加一层过滤，不满足过滤条件的第二个订阅不发布新消息
     * map: 建立两个订阅，中间加一层处理，第一个订阅消息结果处理再通过第二个订阅发布
     */
    filter(predicate: (value?: T) => boolean): Observable<T>;
    map(callbackfn: (value?: T) => T): Observable<T>;
    /**
     * callbackFn 每次发布新消息时的回调
     * seed 起始值
     */
    reduce(callbackFn: (acc?: T, value?: T) => T, initialValue?: T): Observable<unknown>;
    static of<K>(...items: K[]): Observable<K>;
    static from<K>(iteratorObj: Iterable<K>): Observable<K>;
}