import { MarshaledObjectLifetime, RpcMarshalable } from './MarshalableObject';
/**
 * An observer of some value production.
 */
export interface IObserver<T> {
    /**
     * Notifies the observer of the next object in the sequence.
     * @param value The next value in the observable sequence.
     */
    onNext(value: T): void;
    /**
     * Notifies the observer that the end of the sequence has been reached, and that no more values will be produced.
     */
    onCompleted(): void;
    /**
     * Notifies the observer that an error occurred at the value source, and that no more values will be produced.
     * @param reason The error that occurred at the value source.
     */
    onError(reason: any): void;
}
export interface IObservable<T> {
    /**
     * Adds an observer to an observable object.
     * @param observer The observer to receive values.
     * @returns A function to call to cancel the subscription.
     */
    subscribe(observer: IObserver<T>): () => void;
}
export declare class Observer<T> implements IObserver<T>, RpcMarshalable {
    private readonly next;
    private readonly completion?;
    readonly _jsonRpcMarshalableLifetime: MarshaledObjectLifetime;
    error: any;
    get completed(): boolean;
    constructor(next: (value: T) => void, completion?: ((error?: any) => void) | undefined);
    onNext(value: T): void;
    onCompleted(): void;
    onError(reason: any): void;
}