add plist::flatten

  return prop.kind == PropertyKind::VALUE && prop.value == cmp;

}

std::vector<std::string> flatten(const Property& prop) {

  switch (prop.kind) {

    case PropertyKind::VALUE_LITERAL:

    case PropertyKind::VALUE:

      return {prop.value};

    case PropertyKind::TUPLE:

    case PropertyKind::LIST:

      break;

    default:

      return {};

  }

  std::vector<std::string> flat;

  for (const auto& n : *prop.next) {

    auto next = flatten(n);

    flat.insert(flat.end(), next.begin(), next.end());

  }

  return flat;

}

} // namespace plist

bool is_value_quoted(const Property& prop);

bool is_value_quoted(const Property& prop, const std::string& cmp);

std::vector<std::string> flatten(const Property& prop);

} // namespace plist