/**
 * Parses given string expression.
 *
 * @category Parsers
 * @example
 * ```typescript
 * parseStringQuartzExpression("1 1 1 1 1"); // ["*", "1", "1", "1", "1", "1", "*"]
 * parseStringQuartzExpression("1 1 1 1 1 1989"); // ["*", "1", "1", "1", "1", "1", "1989"]
 * parseStringQuartzExpression("1 1 1 1 1 1"); // ["1", "1", "1", "1", "1", "1", "*"]
 * parseStringQuartzExpression("1 1 1 1 1 1 1"); // ["1", "1", "1", "1", "1", "1", "1"]
 * parseStringQuartzExpression(" 1  1   1    1    1   1  1 "); // ["1", "1", "1", "1", "1", "1", "1"]
 * parseStringQuartzExpression("1 1 1 1 1 1 1 1"); // undefined
 * parseStringQuartzExpression("1 1 1 1"); // undefined
 * ```
 * @param source string to be parsed.
 * @returns An array of 7 elements or `undefined` if invalid.
 */
export declare const parseStringQuartzExpression: (
	source: string,
) =>
	| readonly [
			seconds: string,
			minutes: string,
			hours: string,
			dayOfMonth: string,
			month: string,
			dayOfWeek: string,
			year: string,
	  ]
	| undefined;