/** @noSelfInFile */

/**
 * System functions.
 */
declare namespace sys {
    /**
     * Get/set the minimum amount of time between each stepping of the program.
     * By default this is set to `-1`, which means that the program will only be stepped whenever there is new input.
     */
    export function stepinterval(milliseconds?: number): number;

    /**
     * Get the current local date.
     * @tupleReturn
     */
    export function date(): [year: number, month: number, date: number, weekday: number];

    /**
     * End the program with given exitcode when this step is done.
     * This will call the `_shutdown` function with the given exitcode.
     */
    export function exit(code?: number): void;

    /**
     * Load and run given program independently of this program.
     */
    export function exec(filename: string, args?: Array<string>, cwd?: string): boolean;
}