export declare function specifierValidRange(specifier: string, version: string): string;
export declare const VERSION_EXTRACTION_REGEX: RegExp;
/**
 * This function was taken from a different semver library and slightly modified.
 * If passed to Array.prototype.sort, versions will be sorted in descending order.
 */
export declare function compareVersions(version1: string, version2: string): 0 | 1 | -1;
/**
 * Parse extra names inside extras_list
 * there can be multiple extras separated by comma
 * see https://peps.python.org/pep-0508
 *
 * @param extras the contents of an extra list, inside (but not including) the square brackets
 * @returns string array of names
 */
export declare function parseExtraNames(extras?: string): string[];