Dear Hugs-Bugsers,
As reported in Sep. last year,
there is very serious problem
in hugs when it comes to class
hierarchies. See the program
below. Is anyone maintaining
hugs and paying attention to
incoming bug reports?
Thanks,
Ralf
import Monad
class Monad m => C1 m x
-- Monad m is implied by C1 but test diverges if constraint not present
class (C1 m x) => C2 m x
where
c2 :: x -> m x
instance Monad m => C1 m Bool
instance C2 Maybe Bool
where
c2 = return
test :: Maybe Bool
test = c2 True
--
Dr.-Ing. Ralf Laemmel
CWI & VU, Amsterdam, The Netherlands
http://www.cwi.nl/~ralf/
http://www.cs.vu.nl/~ralf/
_______________________________________________
Hugs-Bugs mailing list
[EMAIL PROTECTED]
http://www.haskell.org/mailman/listinfo/hugs-bugs
