import { XMLElement } from './dom-adapter';
/**
 * Strip and collapse ASCII whitespace in a string.
 * Returns empty string for null/undefined input.
 */
export declare const normalizeWhitespace: (str: string | null | undefined) => string;
/**
 * Get normalized text content of an XML element.
 */
export declare const getElementText: (el: XMLElement | null | undefined) => string;
/**
 * Simplified CSS.escape for ID selectors and attribute values.
 * Escapes special characters that need escaping in CSS selectors.
 */
export declare const cssEscape: (str: string) => string;
/**
 * Escape special regex characters in a string.
 */
export declare const regexEscape: (str: string) => string;
/**
 * Replace matches asynchronously and sequentially.
 * Useful when replacement function returns a Promise.
 *
 * @example
 * const result = await replaceSeries(
 *   'Hello {name}',
 *   /\{(\w+)\}/g,
 *   async (match, key) => await lookup(key)
 * )
 */
export declare const replaceSeries: (str: string, regex: RegExp, f: (...args: string[]) => Promise<string>) => Promise<string>;
/**
 * Escape HTML special characters in a string.
 */
export declare const escapeHTML: (str: string) => string;
/**
 * Escape HTML attribute value (quotes only).
 */
export declare const escapeAttr: (str: string) => string;
/**
 * Unescape HTML entities in a string.
 */
export declare const unescapeHTML: (str: string | undefined) => string;
/**
 * Escape XML special characters in a string.
 */
export declare const escapeXML: (str: string) => string;
export declare function extensionFromPath(path: string): string | null;
export declare function extensionFromMime(mimeType: string, path?: string): string;
export declare function getMimeTypeFromPath(path: string): string;
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