LR parsing is an interesting idea - but it's just a tool. A lot of stuff in programming is stated in a way trying to induce the feeling of 'we understand *** - we are elite, while the unwashed masses still use xxx'. There is nothing wrong with learning new things - but to be honest parsing is not that important in the practice of programming any more. If you need it then it is mostly the case of a widespread language that has already good parsers. If you want to improve those parsers - then yes you need to know the theory - but you can also learn some other theory and improve other libraries or maybe learn something higher level like the stuff that Misko Hevery is blogging about and improve your over-all programming practice.