[Haskell-cafe] Monad transformers (was: Is my code too complicated?)

* Andrew Coppin [2010-07-03 14:20:14+0100]

In my experience, using more than one monad transformer at once makes code utterly incomprehensible.

See X monad (xmonad) for an counterexample. -- | The X monad, 'ReaderT' and 'StateT' transformers over 'IO' -- encapsulating the window manager configuration and state, -- respectively. -- -- Dynamic components may be retrieved with 'get', static components -- with 'ask'. With newtype deriving we get readers and state monads -- instantiated on 'XConf' and 'XState' automatically. -- newtype X a = X (ReaderT XConf (StateT XState IO) a) -- Roman I. Cheplyaka :: http://ro-che.info/ "Don't let school get in the way of your education." - Mark Twain