Approximate nearest-neighbor search over region embeddings (boxes, balls).

Point-based ANN indices (HNSW, IVF, Vamana) assume queries and database entries are single vectors. Region embeddings -- axis-aligned boxes, balls, cones -- represent concepts as volumes in embedding space. precinct bridges this gap.

Core abstractions

• [Region] -- trait for geometric regions with center, point-to-region distance, and containment.
• [AxisBox], [Ball] -- concrete region types.
• [RegionIndex] -- ANN index over regions. Builds a point index over region centers, retrieves candidates, reranks with true region distance.

Usage

use precinct::{AxisBox, Region};

let b = AxisBox::new(vec![0.0, 0.0], vec![1.0, 1.0]);
assert!(b.contains(&[0.5, 0.5]));
assert!(!b.contains(&[1.5, 0.5]));
assert_eq!(b.distance_to_point(&[0.5, 0.5]), 0.0);