Method contexts

[Hannah Schroeter]

Hello!

On Sun, Jan 28, 2001 at 02:41:01PM +0000, Marcin 'Qrczak' Kowalczyk wrote:
> [...]

Why can't you write:

> ------------------------------------------------------------------------
> class Member c k where
>     member :: Eq k => c -> k -> Bool

class Eq k => Member c k where
  member :: c -> k -> Bool

> class Member c a => Seq c a

> instance Member [a] a where
>     member s x = x `elem` s

instance Eq a => Member [a] a where
  ...

> instance Seq [a] a
> ------------------------------------------------------------------------

> [...]

Kind regards,

Hannah.