import type { ChartExcelCellValue } from "./chartExcelData.types.js";
/**
 * Coerces a series value into something exceljs writes natively.
 * Numbers and dates are passed through so Excel formats them itself.
 */
export declare function toCell(value: unknown): ChartExcelCellValue;
/**
 * Prefixes text Excel would otherwise evaluate as a formula.
 * Mirrors the Data Grid's Excel serializer.
 */
export declare function escapeFormula(value: ChartExcelCellValue): ChartExcelCellValue;
export declare function toSafeCell(value: unknown, escape: boolean): ChartExcelCellValue;