/**
 * @param doc Source object or array
 * @param isArray True if `doc` is an array
 * @param keepEmptyStrings Whether to keep empty strings
 * @returns An object in which all properties with null, undefined, or empty
 *   string values have been removed, recursively.
 */
export declare function cleanNulls(doc: Record<string, any>, isArray?: boolean, keepEmptyStrings?: boolean): Record<string, any> | any[];
/**
 * @param obj Any reference to check
 * @returns True if obj is an Object as opposed to
 *   something that inherits from Object
 */
export declare function isBasicObject(obj: any): boolean;
/**
 * @method MongoObject.reportNulls
 * @public
 * @param flatDoc An object with no properties that are also objects.
 * @returns An object in which the keys represent the keys in the
 *   original object that were null, undefined, or empty strings, and the value
 *   of each key is "".
 */
export declare function reportNulls(flatDoc: Record<string, string | number | boolean | null | undefined>, keepEmptyStrings?: boolean): Record<string, string>;
export declare function appendAffectedKey(affectedKey: string | null | undefined, key: string): string | null | undefined;
export declare function extractOp(position: string): string | null;
export declare function genericKeyAffectsOtherGenericKey(key: string, affectedKey: string): boolean;
export declare function isNullUndefinedOrEmptyString(val: any): boolean;
export declare function isLength(value: any): boolean;
export declare function isArrayLike(value: any): boolean;
export declare function each(collection: any, iteratee: (item: any, keyOrIndex: number | string, obj: any) => boolean | undefined): void;
export declare function isPrototype(value: unknown): boolean;
export declare function isEmpty(value: any): boolean;
export declare function isObject(value: any): boolean;
export declare function makeKeyGeneric(key: string): string | null;
export declare function keyToPosition(key: string, wrapAll?: boolean): string;
/**
 *  Takes a string representation of an object key and its value
 *  and updates "obj" to contain that key with that value.
 *
 *  Example keys and results if val is 1:
 *    "a" -> {a: 1}
 *    "a[b]" -> {a: {b: 1}}
 *    "a[b][0]" -> {a: {b: [1]}}
 *    'a[b.0.c]' -> {a: {'b.0.c': 1}}
 * @param val Value
 * @param key Key
 * @param obj Object
 */
export declare function expandKey(val: any, key: string, obj: any): void;