switch ($this->lexer->lookahead['type']) {
    case Lexer::T_SELECT:
        $statement = $this->SelectStatement();
        break;

    case Lexer::T_UPDATE:
        $statement = $this->UpdateStatement();
        break;

    case Lexer::T_DELETE:
        $statement = $this->DeleteStatement();
        break;

    default:
        $this->syntaxError('SELECT, UPDATE or DELETE');
        break;
}