hello, Ben Escoto wrote:
Maybe eventually I will see a need for mapWriter. As a passing thought, I wonder how many programmers can read the mapWriterT documentation:
mapWriterT :: (m (a, w) -> n (b, w')) -> WriterT w m a -> WriterT w' n b
and start pounding the code out? Anyway, once I get this all sorted out, I figure my program will have really nice logging, better than fprintf(stderr, ...) even.
you should not use mapWriterT, usually you can get the same behaviour in a different way (i think it should not be exported by the module). by the way once you learn how the tranformers work, you'll be able to guess what that does from its type. however i think it is nice if you can use the transformers witout knowing how they are implemented. if you have access to cvs you might want to look at the revamped monad transformer library in the haskell cvs (fptools/libraries/monads). it is more docuemnted then the current one, but otherwise it is very similar. bye iavor -- ================================================== | Iavor S. Diatchki, Ph.D. student | | Department of Computer Science and Engineering | | School of OGI at OHSU | | http://www.cse.ogi.edu/~diatchki | ==================================================