Regex.close.seen: def of bend-kit-regex@0.8.0.0
Import: import bend-kit-regex@0.8.0.0/regex.bend as Regex
Lines 1043-1050 of bend-kit-regex@0.8.0.0/regex.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-regex@0.8.0.0/regex.bend&start_line=1043&end_line=1050

import Base

# ponytail: trie lookup and membership cost O(log m) per thread step, so a char costs
# O(m log m) for m instructions; a sparse set over an Array would make a step O(1).
def close.seen(hit: Bool, +prog: Trie<Inst>, +pc: U32, caps: List<&2, Maybe<&2, U32>>, stack: List<&2, Th>, seen: Trie<Unit>, out: List<&2, Th>, +pos: U32, +prev: Maybe<&2, Char>, +next: Maybe<&2, Char>) -> Cl:
  match hit:
    case True{}:
      Cl{stack, seen, out}
    case False{}:
      close.inst(trie.at(Inst, prog, pc), pc, caps, stack, trie.set(Unit, seen, pc, Unit{}), out, pos, prev, next)

Uses (13):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Char
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Unit
  https://jend.leeeet.dev/definition.txt?path=bend-kit-regex@0.8.0.0/regex.bend&name=Cl
  https://jend.leeeet.dev/definition.txt?path=bend-kit-regex@0.8.0.0/regex.bend&name=Inst
  https://jend.leeeet.dev/definition.txt?path=bend-kit-regex@0.8.0.0/regex.bend&name=Th
  https://jend.leeeet.dev/definition.txt?path=bend-kit-regex@0.8.0.0/regex.bend&name=Trie
  https://jend.leeeet.dev/definition.txt?path=bend-kit-regex@0.8.0.0/regex.bend&name=close.inst
  https://jend.leeeet.dev/definition.txt?path=bend-kit-regex@0.8.0.0/regex.bend&name=trie.at
  https://jend.leeeet.dev/definition.txt?path=bend-kit-regex@0.8.0.0/regex.bend&name=trie.set