On Wed, Jan 10, 2007 at 09:47:04PM -0000, Claus Reinke wrote: > Bjorn Bringert wrote: > > >The bottom line is that the instance: > > > >instance (MonadTrans t, MonadCGI m, Monad (t m)) => MonadCGI (t m) where > > > >needs both overlapping and undecidable instances, doesn't work in > >Hugs, and probably won't be Haskell'-compatible. > > but overlapping instances were also pioneered in Hugs!-) > > there are differences, eg, in how FDs combine with overlaps, or how scoped > type variables in instances are interpreted, but Hugs has both unlimited > and overlapping instances.
Yes, Hugs accepts this one with +o. Hugs does have additional restrictions on overlapping instances that GHC defers to their point of use, but this particular case is OK, because one of the overlapping instances is a substitution instance of the other. _______________________________________________ Hugs-Users mailing list Hugs-Users@haskell.org http://www.haskell.org/mailman/listinfo/hugs-users