[Haskell-cafe] Generating AST using Parsec

Hi All, I recently came across the paper titled "Monadic Parser Combinators" - After going through it a few times, I think I am beginning to understand monads. However, the parser developed in the paper does not generate an AST - I feel, I'd grasp the whole thing a lot better if I could go over a sample that generates an AST from a simple expression (or even a standard language such as C or Java) ... Can someone please point me to a sample that generates AST - preferably with the simple parser combinator given in the paper. Regards, Kashyap