Marc,
Yes, it is tricky isn't it? I've worked quite hard at improving
GHC's error messages, but they are far from perfect.
So, in this case, what would you *like* the compiler to have said?
I'm the wrong person to answer that question -- you are the right one.
Do others have similar war storie
Dear implementors,
Consider the following silly module definition:
> module Proposal( C ) where
> class C p a where
> ci :: p a -> p a
> f :: (C p a) => f (p a) -> f (p a)
> f a = case ci a of
> [] -> a
Compiling this leads to the following (ghc-4.02):
Proposal.lhs:6:
Infer
