sS tok_formatDollarVars(S pat, MapSO vars) {
  MapSO vars2 = mapKeys addDollarPrefix(vars);
  ifdef tok_formatDollarVars_debug
    printVars tok_formatDollarVars(+pat, +vars, +vars2);
  endifdef
  LS tok = javaTok(pat);
  for (int i = 1; i < l(tok); i += 2) {
    S var = tok.get(i);
    S value = strOrNull(vars2.get(var));
    if (value != null) tok.set(i, value);
  }
  ret join(tok);
}

sS tok_formatDollarVars(S pat, O... _) {
  ret tok_formatDollarVars(pat, paramsToMap(_));
}