class Widget {
  fn describe(mut active: Bool) -> Text {
    if active {
      let inner = Widget { active: false }
      return "on-plain"
    }
    while active {
      active = false
    }
    for part in active {
      return "loop"
    }
    if (Widget { active: true }).active {
      return "on-parenthesized"
    }
    if make(Widget { active: true }) {
      return "on-call-arg"
    }
    if items[Widget { active: true }] {
      return "on-index"
    }
    let w = Widget { active: true, label: "hello" }
    return "off"
  }
}