Cli.descendant: def of cli@0.2.0.0
Import: import cli@0.2.0.0/cli.bend as Cli
Lines 5925-5935 of cli@0.2.0.0/cli.bend: https://jend.leeeet.dev/read.txt?path=cli@0.2.0.0/cli.bend&start_line=5925&end_line=5935

import Base

# T2: the first subcommand in pre-order whose args take the long.
def descendant(items: List<&2, Item>, +prefix: String, +long: String,
    found: Maybe<&2, String>) -> Maybe<&2, String>:
  match items found:
    case _ Some{path}: Some{path}
    case Nil{} None{}: None{}
    case Sub{name, about, +children} <> tail None{}:
      +path = String.concat([prefix, " ", name])
      descendant(tail, prefix, long, descendant(children, path, long,
        owned(find_option(children, long), path)))
    case head <> tail None{}: descendant(tail, prefix, long, None{})

Uses (7):
  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=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.concat
  https://jend.leeeet.dev/definition.txt?path=cli@0.2.0.0/cli.bend&name=Item
  https://jend.leeeet.dev/definition.txt?path=cli@0.2.0.0/cli.bend&name=find_option
  https://jend.leeeet.dev/definition.txt?path=cli@0.2.0.0/cli.bend&name=owned