if (d_debug_)
{
    s_out_ <<  "encountered " << symbol_(token_()) << " in state " <<
                state_() << ": ";

    if (action < 0)             // a reduction was found
        s_out_ << ": reducing by rule " << -action;
    else if (action == 0)
        s_out_ <<  "ACCEPT";
    else
        s_out_ <<  "next state: " << action;

    s_out_ << '\n' << dflush_;
}
