import { Observable, Subscription } from 'rxjs';
import { BlocObserver, Transition } from '../bloc';
export type NextFunction<Event, State> = (value: Event) => Observable<Transition<Event, State>>;
/**
 *
 * Takes a stream of `Events` as input and transforms them into a Stream of `States` as output.
 *
 * @export
 * @abstract
 * @class Bloc
 * @extends {Observable<State>}
 * @template Event
 * @template State
 */
export declare abstract class Bloc<Event, State> extends Observable<State> {
    private _state;
    constructor(_state: State);
    private emitted;
    private eventSubject;
    private stateSubject;
    private transitionSubscription;
    /**
     * The current `BlocObserver`.
     *
     * @static
     * @type {BlocObserver}
     * @memberof Bloc
     */
    static observer: BlocObserver;
    /**
     * Returns the current state of the bloc.
     *
     * @readonly
     * @type {State}
     * @memberof Bloc
     */
    get state(): State;
    /**
     * Adds a Subscription to the bloc's state stream.
     *
     * @param {(value: State) => void} onData
     * @param {(((onError: any) => any) | undefined)} [onError]
     * @param {((() => any) | undefined)} [onDone]
     * @return {*}  {Subscription}
     * @memberof Bloc
     */
    listen(onData: (value: State) => void, onError?: ((onError: any) => any) | undefined, onDone?: (() => any) | undefined): Subscription;
    /**
     * Notifies the bloc of a new event which triggers `mapEventToState`.
     *
     * @param {Event} event
     * @memberof Bloc
     */
    add(event: Event): void;
    /**
     * Called whenever an event is added to the bloc.
     *
     * @param {Event} event
     * @memberof Bloc
     */
    onEvent(event: Event): void;
    /**
     * Transforms the events along with a `NextFunction` into
     * an `Observable<Transition>`.
     * Events that should be processed by `mapEventToState` need to be passed to
     * the `next`.
     * By default `concatMap` is used to ensure all events are processed in
     * the order in which they are received.
     * You can override `transformEvents` for advanced usage in order to
     * manipulate the frequency and specificity with which `mapEventToState` is
     * called as well as which `events` are processed.
     *
     * @param {Observable<Event>} events
     * @param {NextFunction<Event, State>} next
     * @return {*}  {Observable<Transition<Event, State>>}
     * @memberof Bloc
     */
    transformEvents(events: Observable<Event>, next: NextFunction<Event, State>): Observable<Transition<Event, State>>;
    /**
     * Must be implemented when a class extends `Bloc`.
     * Called whenever an event is added to the bloc and
     * is responsible for converting incoming events into outgoing states.
     *
     * @abstract
     * @param {Event} event
     * @return {*}  {AsyncIterableIterator<State>}
     * @memberof Bloc
     */
    abstract mapEventToState(event: Event): AsyncIterableIterator<State>;
    /**
     * Transforms the `Observable<Transition>` into a new `Observable<Transition>`.
     * By default `transformTransitions` returns the incoming `Observable<Transition>`.
     * You can override `transformTransitions` for advanced usage in order to
     * manipulate the frequency and specificity at which `transitions`
     * (state changes) occur.
     *
     * @param {Observable<Transition<Event, State>>} transitions
     * @return {*}  {Observable<Transition<Event, State>>}
     * @memberof Bloc
     */
    transformTransitions(transitions: Observable<Transition<Event, State>>): Observable<Transition<Event, State>>;
    /**
     * Called whenever a `transition` occurs with the given `transition`.
     * A `transition` occurs when a new `event` is added and `mapEventToState` executed.
     * `onTransition` is called before a bloc's state has been updated.
     *
     * @param {Transition<Event, State>} transition
     * @memberof Bloc
     */
    onTransition(transition: Transition<Event, State>): void;
    /**
     * Called whenever an `error` is thrown within `mapEventToState`.
     * By default all errors will be ignored and bloc functionality will be unaffected.
     *
     * @param {*} error
     * @memberof Bloc
     */
    onError(error: any): void;
    /**
     * This method should be called when a `Bloc` is no longer needed.
     * Disposes the resources held by the bloc which means the `Bloc` will
     * no longer process new events after `close` has been called.
     *
     * @memberof Bloc
     */
    close(): void;
    private bindStateSubject;
}