index package:vector-algorithms

index :: Lexicographic e => Int -> e -> Int

vector-algorithms Data.Vector.Algorithms.AmericanFlag

Determines which bucket a given element should inhabit for a particular iteration.

sort2ByIndex :: (PrimMonad m, MVector v e) => Comparison e -> v (PrimState m) e -> Int -> Int -> m ()

vector-algorithms Data.Vector.Algorithms.Optimal

Sorts the elements at the two given indices using the comparison. This is essentially a compare-and-swap, although the first index is assumed to be the lower of the two.

sort3ByIndex :: (PrimMonad m, MVector v e) => Comparison e -> v (PrimState m) e -> Int -> Int -> Int -> m ()

vector-algorithms Data.Vector.Algorithms.Optimal

Sorts the elements at the three given indices. The indices are assumed to be given from lowest to highest, so if 'l < m < u' then 'sort3ByIndex cmp a m l u' essentially sorts the median of three into the lowest position in the array.

sort4ByIndex :: (PrimMonad m, MVector v e) => Comparison e -> v (PrimState m) e -> Int -> Int -> Int -> Int -> m ()

vector-algorithms Data.Vector.Algorithms.Optimal

Sorts the elements at the four given indices. Like the 2 and 3 element versions, this assumes that the indices are given in increasing order, so it can be used to sort medians into particular positions and so on.