fastaggregation64.go

package roaring64

// FastAnd computes the intersection between many bitmaps quickly
// Compared to the And function, it can take many bitmaps as input, thus saving the trouble
// of manually calling "And" many times.
func FastAnd(bitmaps ...*Bitmap) *Bitmap {
	if len(bitmaps) == 0 {
		return NewBitmap()
	} else if len(bitmaps) == 1 {
		return bitmaps[0].Clone()
	}
	answer := And(bitmaps[0], bitmaps[1])
	for _, bm := range bitmaps[2:] {
		answer.And(bm)
	}
	return answer
}

// FastOr computes the union between many bitmaps quickly, as opposed to having to call Or repeatedly.
func FastOr(bitmaps ...*Bitmap) *Bitmap {
	if len(bitmaps) == 0 {
		return NewBitmap()
	} else if len(bitmaps) == 1 {
		return bitmaps[0].Clone()
	}
	answer := Or(bitmaps[0], bitmaps[1])
	for _, bm := range bitmaps[2:] {
		answer.Or(bm)
	}
	return answer
}