On Wed, Apr 12, 2023 at 02:32:43PM +0530, Harendra Kumar wrote: > instance MonadIO m => Monad (T m) where > return = pure > (>>=) = undefined > > instance MonadTrans T where > lift = undefined
I guess it's nothing to do with 9.6 per se, but rather the difference between * https://hackage.haskell.org/package/transformers-0.5.6.2/docs/Control-Monad-Trans-Class.html#t:MonadTrans * https://hackage.haskell.org/package/transformers-0.6.1.0/docs/Control-Monad-Trans-Class.html#t:MonadTrans I'm not sure I can see any solution for this. A monad transformer `T` must give rise to a monad `T m` regardless of what `m` is. If `T m` is only a monad when `MonadIO m` then `T` can't be a monad transformer (under transformers 0.6). Tom _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
