ANTLR tip: Member variables for Lexer and Parser

As I mentioned earlier, I’m in the earliest of early stages when it comes to learning ANTLR and all that it offers. As I’ve been working through an assignment for my Compilers course, I learned another thing that I wanted to share.

Much of the documentation on the web states that an ANTLR grammar file can only add member variables for the parser. I am here to say that this is not true.

Using the @member syntax will only add member variables to the parser, however there is another way.

In your ANTLR grammar, simply change the syntax to: @parser::members {} and @lexer::members {}. This will allow you to declare member variables for the parser and lexer, and reference those member variables in the rules defined within your grammar.

Do you have an ANTLR tip that you can teach me about? Please leave one for me in the comments.