sS format_flex(IF1<O, S> argumentFormatter, S pat, O... args) {
  if (empty(args)) return pat;
  
  LS tok = javaTokPlusPeriod(pat);
  int argidx = 0;
  for (int i = 1; i < tok.size(); i += 2)
    if (tok.get(i).equals("*"))
      tok.set(i, argumentFormatter.get(argidx < args.length ? args[argidx++] : null));
  ret join(tok);
}