Sabberworm\CSS\Parser::parseAtRule PHP Метод

    private function parseAtRule()
    {
        $this->consume('@');
        $sIdentifier = $this->parseIdentifier();
        $this->consumeWhiteSpace();
        if ($sIdentifier === 'import') {
            $oLocation = $this->parseURLValue();
            $this->consumeWhiteSpace();
            $sMediaQuery = null;
            if (!$this->comes(';')) {
                $sMediaQuery = $this->consumeUntil(';');
            }
            $this->consume(';');
            return new Import($oLocation, $sMediaQuery);
        } else {
            if ($sIdentifier === 'charset') {
                $sCharset = $this->parseStringValue();
                $this->consumeWhiteSpace();
                $this->consume(';');
                $this->setCharset($sCharset->getString());
                return new Charset($sCharset);
            } else {
                if ($this->identifierIs($sIdentifier, 'keyframes')) {
                    $oResult = new KeyFrame();
                    $oResult->setVendorKeyFrame($sIdentifier);
                    $oResult->setAnimationName(trim($this->consumeUntil('{', false, true)));
                    $this->consumeWhiteSpace();
                    $this->parseList($oResult);
                    return $oResult;
                } else {
                    if ($sIdentifier === 'namespace') {
                        $sPrefix = null;
                        $mUrl = $this->parsePrimitiveValue();
                        if (!$this->comes(';')) {
                            $sPrefix = $mUrl;
                            $mUrl = $this->parsePrimitiveValue();
                        }
                        $this->consume(';');
                        if ($sPrefix !== null && !is_string($sPrefix)) {
                            throw new \Exception('Wrong namespace prefix ' . $sPrefix);
                        }
                        if (!($mUrl instanceof CSSString || $mUrl instanceof URL)) {
                            throw new \Exception('Wrong namespace url of invalid type ' . $mUrl);
                        }
                        return new CSSNamespace($mUrl, $sPrefix);
                    } else {
                        //Unknown other at rule (font-face or such)
                        $sArgs = trim($this->consumeUntil('{', false, true));
                        $this->consumeWhiteSpace();
                        $bUseRuleSet = true;
                        foreach ($this->blockRules as $sBlockRuleName) {
                            if ($this->identifierIs($sIdentifier, $sBlockRuleName)) {
                                $bUseRuleSet = false;
                                break;
                            }
                        }
                        if ($bUseRuleSet) {
                            $oAtRule = new AtRuleSet($sIdentifier, $sArgs);
                            $this->parseRuleSet($oAtRule);
                        } else {
                            $oAtRule = new AtRuleBlockList($sIdentifier, $sArgs);
                            $this->parseList($oAtRule);
                        }
                        return $oAtRule;
                    }
                }
            }
        }
    }