champ-trie
Copyright 2026 Yuriy Krasilnikov

Persistent hash map based on Compressed Hash-Array Mapped Prefix-tree (CHAMP).
Canonical form. O(1) structural equality via AdHash. COW structural sharing.

References:
  Steindorfer & Vinju, 2015 — "Optimizing Hash-Array Mapped Tries
    for Fast and Lean Immutable JVM Collections", OOPSLA 2015
  Bagwell, 2001 — "Ideal Hash Trees"
