On Mon, Jan 30, 2006 at 05:21:50PM +0300, Bulat Ziganshin wrote:
> the attached program compiles under GHC, but not with Hugs. as far as
> i see, Hugs don't use dependencies in class headers to figure out that
> there is only one "vMkIOError" that can be called in the last
> definition
The example (slightly simplified):
class (Monad m) => Stream m h | h->m where
vMkIOError :: h -> Int
data BinHandle = forall h . Stream IO h => BinH h
instance Stream IO BinHandle where
vMkIOError (BinH h) = vMkIOError h
OK, I think it's a bug (though the example is bizarre).
Sadly Hugs's support for FDs is rough around the edges (and unlikely
to improve soon).
