export declare type UpdateFn<S> = (state: S) => S;
export declare type Subscriber<S> = (state: S) => void;
export declare type Cb<S> = (newV: S, oldV: S, source?: unknown) => void;
export declare type Unsubscribe = () => void;
export interface ITangleContext<S> {
    stateOf(key: KeyOf<S>): S[KeyOf<S>];
    subscribe(key: KeyOf<S>, cb: Cb<S[KeyOf<S>]>): Unsubscribe;
    /**
     * Update the given
     * @param key
     * @param source
     */
    update<C = unknown>(key: KeyOf<S>, newV: S[KeyOf<S>], caller?: C): void;
}
export declare type KeyOf<S> = keyof S;