static Explain explainFull(S input, S rules, S className) {
  ret explainFull(javaTok(input), rules, className);
}
  
static Explain explainFull(L<S> tok, S rules, S className) {
  O parseResult = parse1(tok, rules);
  L e = cast call(parseResult, "explainFull", className);
  if (e == null) ret null;
  ret new Explain(parseResult, e);
}