public Parser classType() {
        if (classTypeParser == null) {
           FutureParser future = scoped("classType");
           classTypeParser = future;
           future.setParser(
               choice(
                   token("NUMERIC"),
                   token("ALPHABETIC"),
                   token("ALPHABETIC-LOWER"),
                   token("ALPHABETIC-UPPER"),
                   token("DBCS"),
                   token("KANJI")
               )
           );
        }

        return classTypeParser;
    }