Hub.heard.at: def of ezx@1.11.0.0
Import: import ezx@1.11.0.0/src/add/hub.bend as Hub
Lines 62-69 of ezx@1.11.0.0/src/add/hub.bend: https://jend.leeeet.dev/read.txt?path=ezx@1.11.0.0/src/add/hub.bend&start_line=62&end_line=69

import Base
import ezx@1.11.0.0/src/lock/world.bend as W

# this reply's answer when it is about the key, else the rest's. The rest
# arrives as a thunk, so the first answer ends the scan.
def heard.at(hit: Bool, answer: W.Answer, rest: Unit -> Maybe<&2, W.Answer>) -> Maybe<&2, W.Answer>:
  match hit:
    case True{}:
      Some{answer}
    case False{}:
      rest(Unit{})

Uses (4):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Unit
  https://jend.leeeet.dev/definition.txt?path=ezx@1.11.0.0/src/lock/world.bend&name=Answer