[Haskell-cafe] Mutual recursive modules with GHC: Classes, instances

[Henning Thielemann]

On Wed, 4 May 2005, Simon Peyton-Jones wrote:

> I'm afraid so, as of today.  It's the kind of thing that could get fixed
> if enough people wanted it, but at the moment it's pretty low on the
> list.

Mutual dependent classes in separate modules are a consequence of 
rigorously defining exactly one class or one principal type per module. In 
my opinion this is a very clean approach, but many library writers seems 
to dislike it. Maybe they dislike it because they risk mutual dependent 
modules ...