/**
 * Checks if provided formula expression is escaped.
 *
 * @param {*} expression Expression to check.
 * @returns {boolean}
 */
export declare function isEscapedFormulaExpression(expression: unknown): boolean;
/**
 * Replaces escaped formula expression into valid non-unescaped string.
 *
 * @param {string} expression Expression to process.
 * @returns {string}
 */
export declare function unescapeFormulaExpression(expression: unknown): unknown;
/**
 * Checks whether string looks like formula or not. Corresponds to {@link https://hyperformula.handsontable.com/api/globals.html#isformula|HyperFormula's implementation}.
 *
 * @param {string} value Checked value.
 * @returns {boolean}
 */
export declare function isFormula(value: unknown): boolean;
/**
 * Checks if provided value is a date according to cell meta.
 *
 * @param {*} value Checked value.
 * @param {string} cellType Type of a cell.
 * @returns {boolean}
 */
export declare function isDate(value: unknown, cellType: unknown): value is string;
/**
 * Checks if provided date is a valid ISO 8601 date string.
 *
 * @param {*} date Checked date.
 * @returns {boolean}
 */
export declare function isDateValid(date: string): boolean;
/**
 * Returns date formatted for HyperFormula (ISO 8601 passthrough).
 *
 * @param {string} date Date string in ISO 8601 format.
 * @returns {string}
 */
export declare function getDateInHfFormat(date: string): string;
/**
 * Returns date formatted for Handsontable (ISO 8601 passthrough).
 *
 * @param {string} date Date string in ISO 8601 format.
 * @returns {string}
 */
export declare function getDateInHotFormat(date: string): string;
/**
 * Converts an HF day-fraction representation of a time value into a string formatted as HH:mm:ss.
 * HyperFormula represents date-time values as a single number, where the integer part
 * encodes the date (days since the HF epoch) and the fractional part encodes the time. This helper
 * ignores the integer part and formats the fractional part as a time string.
 *
 * @param {number} numericTime A number whose fractional part represents the time as a fraction of a day.
 * @returns {string}
 */
export declare function getTimeFromHfTimeFraction(numericTime: number): string;
/**
 * Converts Excel-like dates into ISO 8601 date strings.
 *
 * @param {unknown} numericDate An integer representing numbers of days from the HF epoch (1899-12-30).
 * @returns {string}
 */
export declare function getDateFromExcelDate(numericDate: unknown): string;
/**
 * Converts a Handsontable cell value to a value accepted by HyperFormula.
 * HyperFormula doesn't accept arrays as direct cell values, so they are converted to a
 * comma-separated string.
 *
 * @param {*} value Value to normalize.
 * @returns {*} Value normalized for HyperFormula.
 */
export declare function normalizeValueForFormulaEngine(value: unknown): unknown;