// a cast B ? a.b : ...
// => a instanceof B ? ((B) a).b : ...
svoid tok_castQuestionDot(L<S> tok) {
  for (int i : jfind_all_reversed(tok, "<id> cast <id> ?")) {
    int iEndOfType = indexOf(tok, i, "?");
    int iColon = indexOf(tok, iEndOfType, ":");
    S var = tok.get(i), type = joinSubList(tok, i+4, iEndOfType-1);
    S rawType = tok_dropTypeParameters(type);
    
    tok_insertCasts_reTok(tok, iEndOfType, iColon, var, type);
    tok.set(i+2, "instanceof");
  }
}