[antlr-interest] newbie teething problem(s)

[Chris Black]

James Wilkinson wrote:

> I've been working my way through "An Introduction to ANTLR" and had a 
> couple of things not work as expected:
> [stuff deleted]
> 2. When I got to the AST construction section, I made the changes to 
> the grammar and the Main program and got a null pointer exception. 
> Sure enough, parser.getAST() returns a null pointer. Now I'm totally 
> derailed.
>
> Can somebody give me an idea of what to try now?

I don't know the particular examples you speak of, but for getAST to 
work you need to have an options section that includes buildAST=true; in 
your parser.

Hope that helps,
Chris