Add Down newtype wrapper for reversing orderings
In the same spirit as the newtypes in Data.Monoid, we can also add a newtype for reversing the ordering of a type:
newtype Down a = Down { getDown :: a }
instance Ord a => Ord (Down a) where
Down x < Down y = y < x
-- etc.This newtype is especially useful in combination with sortOn (ticket #2629 (closed)).
Trac metadata
| Trac field | Value |
|---|---|
| Version | 6.8.3 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | libraries/base |
| Test case | |
| Differential revisions | |
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| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |