Tags: tech, lisp,  Date: 2025-05-02 At the 2024 ELS, I gave a talk on adaptive hashing, which focusses on making general purpose hash tables faster and more robust at the same time. Theory vs Practice Hash table theory most concerns itself with the asymptotic worst-case cost with a hash function chosen randomly from a family of hash functions. Although these results are very relevant in practice, those pesky constant factors, that the big-O cost ignores, do matter, and we don't pick hash functio...