Hmap.HMap.join: def of bend-kit-collections@0.1.4.1
Import: import bend-kit-collections@0.1.4.1/hmap.bend as Hmap
Lines 156-170 of bend-kit-collections@0.1.4.1/hmap.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-collections@0.1.4.1/hmap.bend&start_line=156&end_line=170

import Base

# Rebuilds a branch; one with two empty subtries becomes HNil.
def HMap.join(-K: Data, -V: Data, lo: HMap<K, V>, hi: HMap<K, V>) -> HMap<K, V>:
  match lo:
    case HNil{}:
      match hi:
        case HNil{}:
          HNil{}
        case HLeaf{h, es}:
          HBranch{HNil{}, HLeaf{h, es}}
        case HBranch{a, b}:
          HBranch{HNil{}, HBranch{a, b}}
    case HLeaf{h, es}:
      HBranch{HLeaf{h, es}, hi}
    case HBranch{a, b}:
      HBranch{HBranch{a, b}, hi}

Uses (1):
  https://jend.leeeet.dev/definition.txt?path=bend-kit-collections@0.1.4.1/hmap.bend&name=HMap