compareBy

Update: This function is now available in the Data.Ord module under the name comparing.

compareBy :: Ord b => (a -> b) -> a -> a -> Ordering
compareBy f x y = f x `compare` f y

Usage

sortBy (compareBy length) ["abc", "a", "ab"]
↪ ["a","ab","abc"]

This page was created on 2007-10-02 and is filed under Haskell.

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