Add `sortOn` function to Data.List
This passed the vote on the libraries list a while ago, but I forget to add a ticket. The request was to add sortOn
to Data.List
:
-- | Sort a list using a key on each element. This implements the
-- decorate-sort-undecorate paradigm, also called a Schwarzian transform.
sortOn :: Ord b => (a -> b) -> [a] -> [a]
sortOn f = map snd . sortBy (comparing fst) . map (\x -> (f x, x))
Trac metadata
Trac field | Value |
---|---|
Version | 7.8.3 |
Type | FeatureRequest |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | libraries/base |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | ekmett, hvr |
Operating system | |
Architecture |