public static void main(String args[]) {
        if (args.length != 1 && args.length != 2
            || (args.length == 2 && !args[0].equals("-d"))) {
            System.out.println(
                    "Incorrect usage, try: java interpreter.Interpreter [-d] <file>");
            System.exit(1);
        }
        String fileName = args[0];
        boolean debugMode = false;
        if (args.length == 2) {
            fileName = args[1];
            debugMode = true;
        }
        (new Interpreter(fileName, debugMode)).run(debugMode);
    }