The feat/bst branch contains a reimplementation using a red-black tree instead of a simple binary-search index. The differences in the microbenchmarks were approx:
- red-black tree had 2x slower lookup than binary-search index for 10k items
- red-black tree had 2x slower insertions than binary-search index for 10k items
- red-black tree had 2x faster deletions than binary-search index for 10k items
Hence decided to continue using the binary-search index.