import * as Interface from '../interface';

import { Writable } from './writable';

/**

* Create a `Writable` store that allows both updating and reading by subscription.

* @param {*=}value initial value

* @param {StartStopNotifier=}start start and stop notifications for subscriptions

*/

export declare const writable: <T>(value: T, start?: Interface.StartStopNotifier<T>) => Writable<T>;

/**

* Creates a `Readable` store that allows reading by subscription.

* @param value initial value

* @param {StartStopNotifier}start start and stop notifications for subscriptions

*/

export declare const readable: <T>(value?: T | undefined, start?: Interface.StartStopNotifier<T>) => Interface.Readable<T>;

/**

* Derived value store by synchronizing one or more readable stores and

* applying an aggregation function over its input values.

*

* @param stores - input stores

* @param fn - function callback that aggregates the values

* @param initialValue - when used asynchronously

*/

export declare function derived<S extends Interface.Stores, T>(stores: S, callback: (values: Interface.StoresValues<S>, set: (value: T) => void) => Interface.Unsubscriber | void, initialValue?: T): Interface.Readable<T>;