Saving and incrementally updating nearest-neighbor model in R

Question

There are several nearest neighbor R packages (e.g., FNN, RANN, yaImpute) but none of them seem to allow saving off the NN data structure (cover tree, KD tree etc.) so that the

Answer 1

The nabor package lets you build a tree and subsequently perform queries on it. But I don't think it lets you update the tree incrementally.