Flow\Parser::parsePostfixExpression PHP Method

    protected function parsePostfixExpression($node)
    {
        $stop = false;
        while (!$stop && $this->stream->getCurrentToken()->getType() == Token::OPERATOR) {
            switch ($this->stream->getCurrentToken()->getValue()) {
                case '.':
                case '[':
                    $node = $this->parseAttributeExpression($node);
                    break;
                case '|':
                    $node = $this->parseFilterExpression($node);
                    break;
                default:
                    $stop = true;
                    break;
            }
        }
        return $node;
    }