[Haskell-cafe] Type families again

[Roman Leshchinskiy]

On 2 Dec 2010, at 21:29, Andrew Coppin <andrewcoppin at btinternet.com> wrote:

> Does anybody have any suggestions?

class Mappable t a b where
 type Rebind t a b
 map :: (a -> b) -> t -> Rebind a b

This is based on an old C++ trick.

Roman

>