A Down newtype in Data.Ord?
wren ng thornton
wren at freegeek.org
Tue Nov 22 04:04:39 CET 2011
On 11/21/11 10:23 AM, Edward Kmett wrote:
> I have to admit I don't like this color for the same reason as my dislike of the Opposite and Dual suggestions. It isn't entirely clear which operator is being reversed, so you can call me a -1.
Would Converse be any clearer?
The ambiguity of what's being inverted is the reason why I'm not a fan
of Inverse (e.g., we invert multiplication all the time, to the point
where we abuse notation and say we're inverting the numbers themselves).
But other than Reverse and Converse, I can't think of any name that
would immediately invoke the idea that the ordering relation is what's
being dualized. Unless we go the Java route and choose something verbose
like ReverseOrdering (or decide to be really perverse and choose CoOrd).
But really, what else can be reversed? Sorting and ordering functions
can have their outputs reversed. Whereas relations in general are
conversed, binary operators are commuted, arguments to functions are
flipped, components of pairs are swapped,...
More information about the Libraries