Method Rank

roaring64/roaring64.go:397–411

Rank returns the number of integers that are smaller or equal to x (Rank(infinity) would be GetCardinality())

(x uint64)

// Rank returns the number of integers that are smaller or equal to x (Rank(infinity) would be GetCardinality())
func (rb *Bitmap) Rank(x uint64) uint64 {
	size := uint64(0)
	for i := 0; i < rb.highlowcontainer.size(); i++ {
		key := rb.highlowcontainer.getKeyAtIndex(i)
		if key > highbits(x) {
			return size
		}
		if key < highbits(x) {
			size += rb.highlowcontainer.getContainerAtIndex(i).GetCardinality()
		} else {
			return size + rb.highlowcontainer.getContainerAtIndex(i).Rank(lowbits(x))
		}
	}
	return size
}

// Select returns the xth integer in the bitmap
func (rb *Bitmap) Select(x uint64) (uint64, error) {