Thanks Jason. Correct me if i'm wrong but doesn't yacc (or the parser) need something before it (like lex or a tokenizer) to 'tokenize' the text? I can identify the tokens in parse.y but i was looking for a "specification" for them. Example: if i see "class" probably i want to create the token kCLASS, but i wanted to be sure.. Vasco Andrade e Silva -- Posted via http://www.ruby-forum.com/.