2010/12/30 David Leimbach <[email protected]>: > > Reader Writer State is commonly needed in big applications so transformers > provides one for us: > http://hackage.haskell.org/packages/archive/transformers/0.2.2.0/doc/html/Control-Monad-Trans-RWS-Lazy.html > Pretty cool stuff if you ask me. I often wondered about the correct > stacking order of Monad transformers, or how often it mattered.
Thanks, it is very cool indeed! And it turns out that it's not simply kind of the "type RWST r w s m a = ReaderT r WriterT w StateT s m a", it has completely independent implementation. It is done in one layer, so no lifts for tell, get, put, modify and so on. _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
