Hi
I have just discovered Generics in Haskell and, writing some code with GHC, I wondered about the portability of my code.
If you use Data.Generics, your code is not portable - no other Haskell implementation supports the necessary bits.
I can use the -fgenerics to automatically derive instances for Something. But I could wish to have the generated source code for those instances (like, I suppose, the DrIft tool does), for instance, to compile my source with another compiler, which does not support Generics.
Use Derive, which does support Generics: http://www-users.cs.york.ac.uk/~ndm/derive/ If you care about portability, and are not using some of the more advanced features of Generics, then you might want to take a look at Uniplate: http://www-users.cs.york.ac.uk/~ndm/uniplate/ Uniplate does generic traversals, but will work on all Haskell 98 compilers, to some degree - read the paper for exact details. Thanks Neil