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

Henning Thielemann schlepptop at
Wed Jan 7 16:27:09 EST 2009

kahl at schrieb:

> I plead to accelerate the already perceptible shift towards more qualified
> imports, and to treat the unqualified import as the exception.
> Ord is a particularly good candidate for that,
> since it is hogging the whole partial-order namespace
> for the special case of linear orders.
> In your example, if there is only one occurrence of Dual
> in a large module, then
>  >     sortBy (comparing `on` Ord.Dual . fst) stuff
> would be natural. In other places, that module might use ``POrd.Dual''...


> However, if a module uses only Ord duality,
> and uses that a lot, then it may become more readable to
> use an unqualified import (still preferably with an explicit import list)


> and write
>  >     sortBy (comparing `on` Dual . fst) stuff
> For this special case, I don't want to force qualified import,
> but suggest it as standard usage,
> leaving open the more concise second option.


However I don't care about Dual vs. Opposite vs. Reverse.

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