#15566: Implement minimumOn, maximumOn to mirror sortOn -------------------------------------+------------------------------------- Reporter: Garciat | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Research | needed Component: libraries/base | Version: 8.5 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Garciat): Well, `maximumBy` and `minimumBy` are already partial by their use of `Foldable.foldl1`, so I'm thinking it's probably alright to do the more obvious: {{{#!hs import Data.Foldable import Data.Function (on) maximumOn :: (Foldable t, Ord b) => (a -> b) -> t a -> a maximumOn f = maximumBy (compare `on` f) minimumOn :: (Foldable t, Ord b) => (a -> b) -> t a -> a minimumOn f = minimumBy (compare `on` f) }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15566#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler