static S renderStructs(O... params) {
  new L<S> l;
  if (odd(l(params))) l.add(first(params));
  for (int i = l(params) & 1; i+1 < l(params); i += 2)
    l.add(params[i] + "=" + sfu(params[i+1]));
  ret joinWithSpace(l);
}