hello,
sorry for the many posts, today seems to have turned
into a bug reporting day.  there seems to be
a probelm with the type checker of the
current cvs version:

> class {-(Monad m, Monad n) =>-} HasBaseMonad m n | m -> n where
>  mapBase :: (forall a. n a -> n a) -> m a -> m a
>
> instance HasBaseMonad IO IO where
>  mapBase f x = f x

ERROR "hugs-bug.lhs":10 - Illegal type in class constraint

if i comment-in the commented-out part (the Monad constraints)
i get the following:

ERROR "hugs-bug.lhs":11 - Inferred type is not general enough
*** Expression : mapBase
*** Expected type : HasBaseMonad IO IO => (forall c. a c -> a c) -> IO b -> IO b
*** Inferred type : HasBaseMonad IO IO => (forall b. IO b -> IO b) -> IO a -> IO a


if i remove the instance the script loads fine.

-iavor

--
==================================================
| Iavor S. Diatchki, Ph.D. student | | Department of Computer Science and Engineering |
| School of OGI at OHSU |
| http://www.cse.ogi.edu/~diatchki |
==================================================


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