question on type classes

Ashley Yakeley ashley@semantic.org
Tue, 8 May 2001 03:38:25 -0700


At 2001-05-08 03:07, Markus Lauer wrote:

>Hugs sais ERROR Test.hs:20 - syntax error in instance head (constructor 
>           expected)

Invoke as 'hugs -98' to switch on extensions. Hugs will then complain of 
overlapping instances:

instance FooList Char
instance Foo a => FooList a

Yes, I know Char is not an instance of Foo. See the "Anomalous Class 
Fundep Inference" thread.

-- 
Ashley Yakeley, Seattle WA