| I've fixed some of the warnings in transformers, but there are still | 14 of them, triggered by Applicative becoming a superclass of Monad. In GHC's own source code I did this #if __GLASGOW_HASKELL__ < 710 -- Pre-AMP change runGhcT :: (ExceptionMonad m, Functor m) => #else runGhcT :: (ExceptionMonad m) => #endif | I think some of the changes already made are of this sort, exposing | details of the GHC implementation, e.g. the changes to the public | interface of Array and Ratio. For example, it's probably reasonable | to remove the Ix constraint from Data.Array.bounds, but the portable | reference implementation of Data.Array.elems requires Ix, even though | the GHC implementation doesn't. Similarly a portable implementation | of the Functor instance for Array i requires Ix, but the GHC | implementation doesn't. Fair enough. If the Core Libraries Committee wants to add some of these constraints back in, that's fine with me. They just need a comment to explain. (We have a trick, now in the user manual, for how to add a redundant constraint without triggering a complaint.) Simon