static S mech_guessLanguage(S s) {
  try {
    S func = first(mechList_opt("List => Language | Best guessing function"));
    ifdef mech_guessLanguage_debug
    print(func);
    endifdef
    ret (S) callAndMake_extended(func, s);
  } catch e {
    ifdef mech_guessLanguage_debug
    printException(e);
    endifdef
    ret null;
  }
}