Christian Maeder wrote:
> Ben Rudiak-Gould wrote:
>> I just realized that the class Ord should have an additional method:
>>
>> class Eq a => Ord a where
>> compares :: a -> a -> Ordering -> Ordering
>> compares x y d = case compare x y of { EQ -> d ; o -> o }
>> ...
>
> How about:
>
> instance (Ord a, Ord b, Ord c, Ord d) => Ord (a,b,c,d) where
> compare (a1,b1,c1,d1) (a2,b2,c2,d2) =
> compare ((a1,b1,c1),d1) ((a2,b2,c2),d2)
>
> or another tuple nesting)
>
> Christian
That works, but...
Constructing the new tuples is usually more heap allocation, and these short
lived data items can make the garbage collection load higher.
The `mappend` method avoids this pitfall.
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