minimumBy package:base

minimumBy :: Foldable t => (a -> a -> Ordering) -> t a -> a
base Data.List Data.Foldable
The least element of a non-empty structure with respect to the given comparison function. Structure order is used as a tie-breaker: if there are multiple least elements, the leftmost of them is chosen.

Examples

Basic usage: 
>>> minimumBy (compare `on` length) ["Hello", "World", "!", "Longest", "bar"]
"!"
WARNING: This function is partial for possibly-empty structures like lists.
minimumBy :: Foldable1 t => (a -> a -> Ordering) -> t a -> a
base Data.Foldable1
The least element of a non-empty structure with respect to the given comparison function. Structure order is used as a tie-breaker: if there are multiple least elements, the leftmost of them is chosen.
biminimumBy :: Bifoldable t => (a -> a -> Ordering) -> t a a -> a
base Data.Bifoldable
The least element of a non-empty structure with respect to the given comparison function. Structure order is used as a tie-breaker: if there are multiple least elements, the leftmost of them is chosen.

Examples

Basic usage: 
>>> biminimumBy compare (42, 17)
17

>>> biminimumBy compare (Left 17)
17

>>> biminimumBy compare (BiList [42, 17, 23] [-5, 18])
-5
On empty structures, this function throws an exception: 
>>> biminimumBy compare (BiList [] [])
*** Exception: bifoldr1: empty structure
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