class parameters to existential datatypes

Ashley Yakeley ashley@semantic.org
Thu, 6 Dec 2001 13:11:07 -0800


At 2001-12-06 13:04, John Hughes wrote:

>	> data Foo c = forall a . c a => Foo a

What are you trying to say? In 'data Foo c' you are saying that c is a 
type (as a parameter). In 'c a =>' you are saying that c is a class. So 
naturally Haskell complains.

-- 
Ashley Yakeley, Seattle WA