On Tue, Jan 09, 2007 at 05:54:11PM -0800, David Roundy wrote:
I think you'd want a higher-kinded list type rather than a MPTC:
class List l where cons :: e -> l e -> l e -- you can't make a constructor a member of a class head :: l e -> e null :: l e -> Bool empty :: l e ...
Okay, this was stupid of me. As Spencer points out, we wouldn't actually want a list type with kind * -> *, because we'd want to support specialized lists like Data.Bytestring. So we'd want something more like
class List l e, l -> e where cons :: e -> l -> l head :: l -> e null :: l -> Bool empty :: l ...
(But I don't like functional dependencies, because they confuse me, and hope that associated types end up making it into Haskell'...) -- David Roundy http://www.darcs.net