[Haskell-cafe] Typechecking Using GHC API

Hi, I do some pre-processing on a normal Haskell code ( -F ). The pre-processor needs to know the type of each expression. What are the possibilities to do so? Can I use GHC API to employ GHC type checker? If yes, any good tutorial? Is it too naive to think of a function, f :: String -> AnnotatedAST , that takes Haskell code and returns its corresponding abstract syntax tree annotated with types? Thanks, /shayan