hello, i am a bit stuck on the following problem, which seems to be GHC related. consider the following two modules:
> {-# OPTIONS -fglasgow-exts -fallow-overlapping-instances #-}
> module Test where
>
> data T m a = T (m a)
>
> class C m where get :: m a
>
> instance C (T m)
> instance C m => C (t m)
>
> obs :: T [] Int
> obs = get> module Test1 where > > import Test > > obs' :: T [] Int > obs' = get
i can load the first one (Test) without problems,
but when i load the second one (Test1) a get the error:
Test1.hs:6:
No instance for (C [])
arising from use of `get' at Test1.hs:6
In the definition of `obs'': obs' = getthis seems to indicate that the second instance is being used, but i cannot figure out why. am i doing something silly here?
-iavor ps: i am not on the GHC users list so please cc me if you replay there
--
==================================================
| Iavor S. Diatchki, Ph.D. student | | Department of Computer Science and Engineering |
| School of OGI at OHSU |
| http://www.cse.ogi.edu/~diatchki |
==================================================
_______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
