/// <reference types="@rbxts/compiler-types" />
export declare type Actions<S, K> = {
    [P in keyof K]: K[P] extends (state: S, ...a: infer P) => void ? (...a: P) => void : never;
};
export declare type Subscriber<S> = (newState: S, oldState: S) => void;
export declare type Selector<S, T> = (state: S) => T;
export declare type Observer<T> = (value: T) => void;
export declare type SelectionChanged<T> = (newValue: T, oldValue: T) => boolean;
export interface Silo<S extends object, M extends object> {
    /** The initial state of the Silo. */
    initialState: Readonly<S>;
    /** Actions associated with the silo. These are used to modify the state. */
    actions: Actions<S, M>;
    /** Get the current state. */
    getState: () => Readonly<S>;
    /** Subscribe to changes to the state. */
    subscribe: (subscriber: Subscriber<S>) => () => void;
    /** Observe a selection of the state. Optional `changed` callback can be used to check if the given value actually changed. */
    /**
     * Observe a selection of the state. The selector is called immediately as well
     * as after every state change. The observer is called with the given selected
     * value anytime the selected value changes.
     *
     * Optional `changed` callback can be used to check if the given value actually
     * changed. If not supplied, a simple equality check (`old !== new`) is used instead.
     * The observer will only only be called if the value has changed.
     */
    observe: <T>(selector: Selector<S, T>, observer: Observer<T>, changed?: SelectionChanged<T>) => () => void;
    /** Disconnect subscribers and observers. */
    destroy: () => void;
}