Proposal #2560 again: add newtype Down/ReverseOrd to Data.Ord

roconnor at roconnor at
Wed Jan 7 10:25:14 EST 2009

On Wed, 7 Jan 2009, Stefan Holdermans wrote:

> Twan,
>> How about:
>> -- intended for |qualified| import |as Ord|:
>> newtype Dual a = Dual { unDual :: a } deriving Eq
> +1 for Dual.

+1 for Dual.  The term seems common in lattice theory.  I use it myself.

Russell O'Connor                                      <>
``All talk about `theft,''' the general counsel of the American Graphophone
Company wrote, ``is the merest claptrap, for there exists no property in
ideas musical, literary or artistic, except as defined by statute.''

More information about the Libraries mailing list