/**
 * Utilities for interrogating variables (e.g. checking data types).
 *
 * @public
 * @module lang/is
 */
/**
 * Returns true if the argument is a number. NaN will return false.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function number(candidate: any): boolean;
/**
 * Returns true if the argument is NaN.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function nan(candidate: any): boolean;
/**
 * Returns true if the argument is a valid 32-bit integer.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function integer(candidate: any): boolean;
/**
 * Returns true if the argument is a valid integer (which can exceed 32 bits); however,
 * the check can fail above the value of Number.MAX_SAFE_INTEGER.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function large(candidate: any): boolean;
/**
 * Returns true if the argument is a positive number.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function positive(candidate: any): boolean;
/**
 * Returns true if the argument is a negative number.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function negative(candidate: any): boolean;
/**
 * Returns true if the argument is iterable.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function iterable(candidate: any): boolean;
/**
 * Returns true if the argument is a string.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function string(candidate: any): boolean;
/**
 * Returns true if the argument is a JavaScript Date instance.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function date(candidate: any): boolean;
/**
 * Returns true if the argument is a JavaScript RegExp instance.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function regexp(candidate: any): boolean;
/**
 * Returns true if the argument is a function.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function fn(candidate: any): boolean;
/**
 * Returns true if the argument is an array.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function array(candidate: any): boolean;
/**
 * Returns true if the argument is a boolean value.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function boolean(candidate: any): boolean;
/**
 * Returns true if the argument is a non-null object.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function object(candidate: any): boolean;
/**
 * Returns true if the argument is null.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function nil(candidate: any): boolean;
/**
 * Returns true if the argument is undefined.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function undef(candidate: any): boolean;
/**
 * Returns true if the argument is a zero-length string.
 *
 * @static
 * @public
 * @param {*} candidate
 * @returns {boolean}
 */
export function zeroLengthString(candidate: any): boolean;
/**
 * Given two classes, determines if the "child" class extends
 * the "parent" class (without instantiation).
 *
 * @public
 * @param {Function} parent
 * @param {Function} child
 * @returns {boolean}
 */
export function extension(parent: Function, child: Function): boolean;