There's only one question in your post: "what kind of question is this?". I answered it. Yes, I know about lexical analyzers. Do you have any specific question? I have a couple: are you listening in class? Have you heard of Google? What is your goal? Have you tried reaching it on your own? Will 'u' and 'ur' for 'you' and 'your' pass a lexical test? Is AOL-speak and laziness endemic? Is it required of a productive programmer?