sS format3_curly(S pat, S... args) {
  if (args.length == 0) return pat;
  
  L<S> tok = javaTok(pat);
  int argidx = 0;
  for (int i = 1; i < tok.size(); i += 2)
    if (tok.get(i).equals("*"))
      tok.set(i, curly(argidx < args.length ? args[argidx++] : "null"));
  return join(tok);
}

Began life as a copy of #1001250