selector

type IntroSelector interface {
	Swap(i, j int)

	// Compare entries found in slots i and j.
	// The contract for the returned value is the same as Comparator.compare(Object, Object).
	Compare(i, j int) int
}

type RadixSelector interface {
	Swap(i, j int)
	ByteAt(i, k int) int
}

type Selector interface {
	SelectK(from, to, k int)
}