Parameterising Class Constraints in Existential Types

Ashley Yakeley
Thu, 29 Mar 2001 01:46:59 -0800

Is this valid (extended) Haskell?

class MyClass a b where
	foo :: a -> b -> Int

data Special = forall b. (MyClass Int b)=> MkSpecial b
data General a = forall b. (MyClass a b)=> MkGeneral b

Hugs complains about the 'General' line but has no problem with the 
'Special' line...

Ashley Yakeley, Seattle WA