> I would appreciate pointers to an LL parser generator. It's a little
> easier to think about my project as top down.

OCaml's stream parsers make it easy to write recursive-descent
parsers.  For more advanced facilities such as precendences and
automatic left-factoring of the rules, please have a look at Camlp4:
        http://caml.inria.fr/camlp4/

Hope this helps,

- Xavier Leroy