RE: Empty classes of type variables which take an argument.

2000-09-11 Thread Mark P Jones
| The attached file is accepted by GHC 4.08 and Hugs 98. Here is what was in the attached file: module Foo where class A a where foo :: a value -> () class A a => B a where toList :: a value -> [value] | However if you remove the declaration of "foo" (and for Hugs, | the

Empty classes of type variables which take an argument.

2000-09-11 Thread George Russell
The attached file is accepted by GHC 4.08 and Hugs 98. However if you remove the declaration of "foo" (and for Hugs, the now unnecessary "where" in the declaration of class A), both compilers complain. It appears that in the absence of any information, GHC and Hugs assume that the subject of a c