import { Subscriber } from '../Subscriber';
import { Scheduler } from '../Scheduler';
import { Observable } from '../Observable';
/**
 * We need this JSDoc comment for affecting ESDoc.
 * @extends {Ignored}
 * @hide true
 */
export declare class IntervalObservable extends Observable<number> {
    private period;
    private scheduler;
    /**
     * Creates an Observable that emits sequential numbers every specified
     * interval of time, on a specified Scheduler.
     *
     * <span class="informal">Emits incremental numbers periodically in time.
     * </span>
     *
     * <img src="./img/interval.png" width="100%">
     *
     * `interval` returns an Observable that emits an infinite sequence of
     * ascending integers, with a constant interval of time of your choosing
     * between those emissions. The first emission is not sent immediately, but
     * only after the first period has passed. By default, this operator uses the
     * `async` Scheduler to provide a notion of time, but you may pass any
     * Scheduler to it.
     *
     * @example <caption>Emits ascending numbers, one every second (1000ms)</caption>
     * var numbers = Rx.Observable.interval(1000);
     * numbers.subscribe(x => console.log(x));
     *
     * @see {@link timer}
     * @see {@link delay}
     *
     * @param {number} [period=0] The interval size in milliseconds (by default)
     * or the time unit determined by the scheduler's clock.
     * @param {Scheduler} [scheduler=async] The Scheduler to use for scheduling
     * the emission of values, and providing a notion of "time".
     * @return {Observable} An Observable that emits a sequential number each time
     * interval.
     * @static true
     * @name interval
     * @owner Observable
     */
    static create(period?: number, scheduler?: Scheduler): Observable<number>;
    static dispatch(state: any): void;
    constructor(period?: number, scheduler?: Scheduler);
    protected _subscribe(subscriber: Subscriber<number>): void;
}
