public Parser valueOf() {
        if (valueOfParser == null) {
           FutureParser future = scoped("valueOf");
           valueOfParser = future;
           future.setParser(
               sequence(
                   token("VALUE"),
                   token("OF"),
                   plus(
                       sequence(
                           choice(
                               token("IDENTIFICATION"),
                               token("ID"),
                               cobolWord()
                           ),
                           optional(
                               token("IS")
                           ),
                           choice(
                               dataName(),
                               literal()
                           )
                       )
                   )
               )
           );
        }

        return valueOfParser;
    }