static boolean hadError = false;

        // Indicate an error in the exit code.
        if (hadError)
            System.exit(65);

            hadError = false;

    static void error(int line, String message) {
        report(line, "", message);
    }
    private static void report(int line, String where,
            String message) {
        System.err.println(
                "[line " + line + "] Error" + where + ": " + message);
        hadError = true;
    }