Refinement

refine re-selects the neighbors of every stored entry against the finished graph and returns a DenseRefineReport: the entries re-selected and changed, the islands found and reconnected, and the closing audit. A cheap insertion pass followed by one refinement reaches a better graph in less total time than one expensive insertion pass. Zero changed means the graph has settled, and searches may run throughout.

while try index.on(executor).refine(config: DenseRefineConfig(expansionFactor: 128)).changed != 0 {}

§ Absorbing & Splitting

Bigger indexes come from absorbing, never mutating: absorb appends every donor’s entries with its graph, then refines across the appended part. It consumes every donor it absorbs, so every later verb on one reports uninitialized, and an absorb stopped early hands the rest back to their indexes.

try index.on(executor).absorb([shard])

split is the inverse: it hands graph-local parts of the index to empty receivers of the same configuration, one part each, keeping their edges and leaving the index empty but live. Both report the closing refines as refine does.

let report = try index.on(executor).split(into: [left, right], config: DenseSplitConfig(seed: 42))