/**
 * 判断是否为一个 URL
 *
 * @param {*} target 目标
 */
export declare function isUrl(target: string): boolean;
/**
 * 判断是否为电子邮箱
 *
 * 参考 https://html.spec.whatwg.org/multipage/forms.html#e-mail-state-(type=email)
 *
 * @param {*} target 目标
 */
export declare function isEmail(target: string): boolean;
/**
 * 判断是否为手机号
 *
 * @param {*} target 目标
 */
export declare function isCellphone(target: string): boolean;