import { type Maybe } from '../value/maybe.type';
import { type StoredDataStorageKey } from './storage';
/**
 * Limited Class/Interface for storing string values synchronously.
 */
export declare abstract class SimpleStorageObject {
    /**
     * Retrieves an item from storage.
     *
     * @param key The key of the item to retrieve.
     * @returns The item string if found, otherwise null or undefined.
     */
    abstract getItem(key: StoredDataStorageKey): Maybe<string>;
    /**
     * Sets an item in storage.
     *
     * @param key The key of the item to set.
     * @param item The item string to store. If null or undefined, the item may be removed depending on implementation.
     */
    abstract setItem(key: StoredDataStorageKey, item: Maybe<string>): void;
    /**
     * Removes an item from storage.
     *
     * @param key The key of the item to remove.
     */
    abstract removeItem(key: StoredDataStorageKey): void;
}
/**
 * Synchronous Class/Interface for storing string values.
 *
 * Has the same interface as localStorage for the web.
 */
export declare abstract class StorageObject extends SimpleStorageObject {
    /**
     * The number of items stored in the storage object.
     */
    abstract readonly length: number;
    /**
     * Returns the string key for the index.
     *
     * Returns null if no key available.
     *
     * @param index The index of the key to retrieve.
     * @returns The key string if found, otherwise null.
     */
    abstract key(index: number): string | null;
}
/**
 * Extended synchronous Class/Interface for storing string values with additional properties.
 */
export declare abstract class FullStorageObject extends StorageObject {
    /**
     * Whether or not the storage is persistant.
     */
    abstract readonly isPersistant: boolean;
    /**
     * Whether or not the storage is available for use.
     */
    abstract readonly isAvailable: boolean;
    /**
     * Removes all items from storage.
     *
     * @returns An array of keys that were removed.
     */
    abstract removeAll(): string[];
}
/**
 * Utility class for working with StorageObject instances.
 */
export declare class StorageObjectUtility {
    /**
     * Retrieves all keys from a StorageObject, optionally filtering by a prefix.
     *
     * @param storageObject The StorageObject to retrieve keys from.
     * @param prefix Optional prefix to filter keys by.
     * @returns An array of StoredDataStorageKey.
     */
    static allKeysFromStorageObject(storageObject: StorageObject, prefix?: string): StoredDataStorageKey[];
}