static L<S> tokSplitAtComma(S s) {
  L<S> tok = javaTok(s);
  new L<S> l;
  while (l(tok) > 1) {
    int i = smartIndexOf(tok, ",");
    l.add(trim(join(subList(tok, 0, i))));
    tok = subList(tok, i+1);
  }
  ret l;
}