import type { SimpleData } from '../../common';
/**
 * 维值转为字符串时, 如果是null/undefined, 则添加标记, 便于转回来.
 * null/undefined => "$$null$$/$$undefined$$"
 */
export declare const generateNillString: (value: SimpleData) => string;
/**
 * 维值如果含有空值标记, 则转换为 null/undefined.
 * "$$null$$/$$undefined$$"" => null/undefined
 */
export declare const resolveNillString: (value: string) => string | null | undefined;
export declare const generateId: (...ids: SimpleData[]) => string;
export declare const resolveId: (id?: string) => SimpleData[];