Hi! There are some use cases where we need to find vectors with the distance (by some metric) to the given vector V less than the given threshold T. That task is very similar to the knn problem, but in this case we don't have a quantity of the nearest neighbours *k*.
As I see, the current implementation of knn doesn't provide such functionality. But at the first glance it is not very difficult to modify the method *search* of *HnswGraph *to implement that feature (do not limit *result* size and get rid of candidates which exceed threshold). But maybe that idea has some not obvious problems which I haven't noticed, and in reality an implementation of that idea would have fundamental difficulties?
