In fact, if you just want Read-like functionality for a set of Haskell datatypes, use polyparse: the DrIFT tool can derive polyparse's Text.Parse class (the equivalent of Read) for you, so you do not even need to write the parser yourself!
Cabal install DrIFT-cabalized complains. What is the module "Rules"? I've never seen it before. Is there a quick fix? I didn't see a "build-depends" line in my ~/.cabal/config file. e0082888@e0082888-laptop:~$ cabal install DrIFT-cabalized Resolving dependencies... Configuring DrIFT-cabalized-2.2.3.1... Preprocessing executables for DrIFT-cabalized-2.2.3.1... Building DrIFT-cabalized-2.2.3.1... src/DrIFT.hs:19:17: Could not find module `Rules': It is a member of the hidden package `ghc-6.12.2'. Perhaps you need to add `ghc' to the build-depends in your .cabal file. Use -v to see a list of the files searched for. cabal: Error: some packages failed to install: DrIFT-cabalized-2.2.3.1 failed during the building phase. The exception was: ExitFailure 1