[Haskell-cafe] Flow Graphs for Language-independent Code Representation

Hi *^o^*, I'm working on a source code transformation project for numerical automatic differentiation for Fortran and C. I would love to know the best Haskell way/package available today to represent procedural (non-OO) code in a language-independent manner. Any tips or resource, paper references are most welcome! Regards, Cetin Sert