import { Stream, MemoryStream } from 'xstream';
import { Scope, Reducer } from './types';
export declare function isolateSource<T, R>(source: StateSource<T>, scope: Scope<T, R>): StateSource<R>;
export declare function isolateSink<T, R>(innerReducer$: Stream<Reducer<R>>, scope: Scope<T, R>): Stream<Reducer<T>>;
/**
 * Represents a piece of application state dynamically changing over time.
 */
export declare class StateSource<S> {
    state$: MemoryStream<S>;
    private _state$;
    private _name;
    constructor(stream: Stream<any>, name: string);
    /**
     * Selects a part (or scope) of the state object and returns a new StateSource
     * dynamically representing that selected part of the state.
     *
     * @param {string|number|lens} scope as a string, this argument represents the
     * property you want to select from the state object. As a number, this
     * represents the array index you want to select from the state array. As a
     * lens object (an object with get() and set()), this argument represents any
     * custom way of selecting something from the state object.
     */
    select<R>(scope: Scope<S, R>): StateSource<R>;
    isolateSource: typeof isolateSource;
    isolateSink: typeof isolateSink;
}