Method Rank

roaring.go:1259–1273

Rank returns the number of integers that are smaller or equal to x (Rank(infinity) would be GetCardinality()). If you pass the smallest value, you get the value 1. If you pass a value that is smaller than the smallest value, you get 0. Note that this function differs in convention from the Select fu

(x uint32)

// value, you get 0. Note that this function differs in convention from the Select function since it
// return 1 and not 0 on the smallest value.
func (rb *Bitmap) Rank(x uint32) 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 += uint64(rb.highlowcontainer.getContainerAtIndex(i).getCardinality())
		} else {
			return size + uint64(rb.highlowcontainer.getContainerAtIndex(i).rank(lowbits(x)))
		}
	}
	return size
}

// CardinalityInRange returns the number of integers that are in the half-open range [start, end).
// It is equivalent to Rank(uint32(end-1)) - Rank(uint32(start-1)) for start > 0,