Introduction - If you have any usage issues, please Google them yourself
You can start with simple actions, like printing out some message. Before defining rules, remember that you can define macros (like the provided macros LETTER, DIGIT and WHITESPACE). The action of each rule must return a java_cup.runtime.Symbol object. There are two constructors for the java_cup.runtime.Symbol class:
Symbol(int tokenNumber): this constructor is used when there is no value associated with the token (like for EOF)
Symbol(int tokenNumber, Object tokenVal): this constructor is used when the token has a value (for example, for an INT token the value is the value of the integer)