import type { Axis, Extra } from './types';
export declare const isAxis: (value: any) => value is Axis;
export declare const generateArrayIndex: (data: any[], extraIndex?: Axis[]) => Axis[];
export declare const flatObject: (obj: any, concatenator?: string) => any;
export declare const fillMissingValue: (datum: any, fillValue: any) => any;
export declare const generateSplit: (length: number) => string;
export declare const stringify: (value: any) => string;
export declare const getStringifyLength: (value: any) => number;
/**
 * Convert data to specified data type.
 * @param datum
 * @param type
 * @returns converted data
 */
export declare const convertDataType: (data: any, type: Extra['columnTypes'][number]) => any;