/**
 * Base utility functions shared between Node.js and Browser
 * All functions use standard Web APIs that work in both environments
 * (Node.js 16+ supports atob/btoa/TextEncoder/TextDecoder globally)
 */
/**
 * Convert base64 string to Uint8Array
 * Uses native Buffer in Node.js for better performance
 */
export declare function base64ToUint8Array(base64: string): Uint8Array;
export declare function delay(ms: number): Promise<void>;
export declare function dateToExcel(d: Date, date1904?: boolean): number;
export declare function excelToDate(v: number, date1904?: boolean): Date;
/**
 * Parse an OOXML date string into a Date object.
 * OOXML dates like "2024-01-15T00:00:00" lack a timezone suffix,
 * which some JS engines parse as local time. Appending "Z" forces UTC.
 */
export declare function parseOoxmlDate(raw: string): Date;
/**
 * Decode OOXML `_xHHHH_` escape sequences in a string.
 *
 * Used when reading text content from `<t>` elements in shared strings,
 * rich text runs, and inline strings. The replacement works left-to-right,
 * so `_x005F_x000D_` correctly decodes to the literal string `_x000D_`
 * (the `_x005F_` decodes to `_`, consuming the match).
 */
export declare function decodeOoxmlEscape(text: string): string;
/**
 * Encode literal `_xHHHH_` patterns in a string for OOXML output.
 *
 * If a string naturally contains the pattern `_xHHHH_` (e.g., the user typed
 * `_x000D_`), the leading underscore must be escaped as `_x005F_` to prevent
 * readers from misinterpreting it as an escape sequence.
 *
 * Roundtrip guarantee: `decodeOoxmlEscape(encodeOoxmlEscape(s)) === s`
 */
export declare function encodeOoxmlEscape(text: string): string;
/**
 * Encode a string for safe use in an OOXML **XML attribute** value.
 *
 * Two transformations are applied (order matters):
 * 1. Literal `_xHHHH_` patterns are escaped (`_x005F_xHHHH_`) so readers
 *    do not misinterpret them as escape sequences.
 * 2. Characters that XML attribute-value normalisation would mangle
 *    (`\t`, `\n`, `\r`) are encoded as `_x0009_`, `_x000A_`, `_x000D_`.
 *
 * This is the write-side counterpart of {@link decodeOoxmlEscape}.
 * Use `encodeOoxmlEscape` for element **text** content and this function
 * for **attribute** values.
 */
export declare function encodeOoxmlAttr(text: string): string;
export { xmlEncode, xmlDecode } from "../modules/xml/encode.js";
export declare function validInt(value: string | number): number;
/**
 * Split an Excel numFmt string by semicolons, respecting quoted strings and brackets.
 *
 * Excel numFmt can have up to 4 sections: `positive ; negative ; zero ; text`.
 * Semicolons inside `"..."` (literal text) or `[...]` (locale/color tags) must NOT
 * be treated as section separators.
 */
export declare function splitFormatSections(fmt: string): string[];
export declare function isDateFmt(fmt: string | null | undefined): boolean;
export declare function parseBoolean(value: unknown): boolean;
export declare function range(start: number, stop: number, step?: number): Generator<number>;
export declare function toSortedArray<T>(values: Iterable<T>): T[];
/**
 * Convert a Buffer, ArrayBuffer, or Uint8Array to a UTF-8 string
 * Works in both Node.js and browser environments
 */
export declare function bufferToString(chunk: ArrayBuffer | Uint8Array | string): string;
/**
 * Convert Uint8Array to base64 string
 * Uses native Buffer in Node.js, optimized chunked conversion in browser
 */
export declare function uint8ArrayToBase64(bytes: Uint8Array): string;
/**
 * Convert string to UTF-16LE Uint8Array (used for Excel password hashing)
 */
export declare function stringToUtf16Le(str: string): Uint8Array;
/**
 * Yield to the event loop via a macrotask.
 * Uses `setTimeout(0)` which works in both Node.js and browsers.
 */
export declare function yieldToEventLoop(): Promise<void>;