Add sortOn and other *On functions
Almost all uses of sortBy
are of the form sortBy (comparing f)
, sortBy (compare
on f)
or an equivalent construction. I propose that we add the more convenient function sortOn
to Data.List:
sortOn :: Ord b => (a -> b) -> [a] -> [a]
For consistency for the other By
functions we should also add an On
equivalent:
nubOn :: Eq b => (a -> b) -> [a] -> [a]
deleteOn :: Eq b => (a -> b) -> a -> [a] -> [a]
deleteFirstsOn :: Eq b => (a -> b) -> [a] -> [a] -> [a]
unionOn :: Eq b => (a -> b) -> [a] -> [a] -> [a]
intersectOn :: Eq b => (a -> b) -> [a] -> [a] -> [a]
groupOn :: Eq b => (a -> b) -> [a] -> [[a]]
sortOn :: Ord b => (a -> b) -> [a] -> [a]
insertOn :: Ord b => (a -> b) -> a -> [a] -> [a]
maximumOn :: Ord b => (a -> b) -> [a] -> a
minimumOn :: Ord b => (a -> b) -> [a] -> a
Trac metadata
Trac field | Value |
---|---|
Version | 6.9 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | libraries/base |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |