BitTree.union_bits: def of mylsm-lsm-store@0.6.0.1
Import: import mylsm-lsm-store@0.6.0.1/src/BitTree.bend as BitTree
Lines 199-221 of mylsm-lsm-store@0.6.0.1/src/BitTree.bend: https://jend.leeeet.dev/read.txt?path=mylsm-lsm-store@0.6.0.1/src/BitTree.bend&start_line=199&end_line=221

import Base

# Word-wise union for chunked Bloom builds. Both sides always share the exact
# shape (same height from the same bit count); mismatched arms are unreachable
# by construction and keep the Fork side.
def union_bits(ta: WordTree, tb: WordTree) -> WordTree:
  match ta tb:
    case Empty{} Empty{}:
      Empty{}
    case Empty{} Leaf{wb}:
      Leaf{wb}
    case Empty{} Fork{lb, rb}:
      Fork{lb, rb}
    case Leaf{wa} Empty{}:
      Leaf{wa}
    case Leaf{wa} Leaf{wb}:
      Leaf{U32.or(wa, wb)}
    case Leaf{wa} Fork{lb, rb}:
      Fork{lb, rb}
    case Fork{la, ra} Empty{}:
      Fork{la, ra}
    case Fork{la, ra} Leaf{wb}:
      Fork{la, ra}
    case Fork{la, ra} Fork{lb, rb}:
      Fork{union_bits(la, lb), union_bits(ra, rb)}

Uses (2):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.or
  https://jend.leeeet.dev/definition.txt?path=mylsm-lsm-store@0.6.0.1/src/BitTree.bend&name=WordTree