From 22826b249c0cb98f9a62f361eb8faf3f28d8d2f3 Mon Sep 17 00:00:00 2001
From: raxbg <crownandthering@gmail.com>
Date: Fri, 5 Oct 2018 16:41:05 +0300
Subject: [PATCH 01/13] Add prepend and replace methods

---
 lib/Sabberworm/CSS/CSSList/CSSList.php | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/lib/Sabberworm/CSS/CSSList/CSSList.php b/lib/Sabberworm/CSS/CSSList/CSSList.php
index bc90460b..84113058 100644
--- a/lib/Sabberworm/CSS/CSSList/CSSList.php
+++ b/lib/Sabberworm/CSS/CSSList/CSSList.php
@@ -31,6 +31,10 @@ public function getLineNo() {
 		return $this->iLineNo;
 	}
 
+	public function prepend($oItem) {
+		array_unshift($this->aContents, $oItem);
+	}
+
 	public function append($oItem) {
 		$this->aContents[] = $oItem;
 	}
@@ -48,6 +52,19 @@ public function remove($oItemToRemove) {
 		return false;
 	}
 
+	/**
+	 * Replaces an item from the CSS list.
+	 * @param RuleSet|Import|Charset|CSSList $oItemToRemove May be a RuleSet (most likely a DeclarationBlock), a Import, a Charset or another CSSList (most likely a MediaQuery)
+	 */
+	public function replace($oOldItem, $oNewItem) {
+		$iKey = array_search($oOldItem, $this->aContents, true);
+		if ($iKey !== false) {
+			array_splice($this->aContents, $iKey, 1, $oNewItem);
+			return true;
+		}
+		return false;
+	}
+
 	/**
 	 * Set the contents.
 	 * @param array $aContents Objects to set as content.

From 9ed24ad97b6586029fa23af7daaebbbe3eaf6251 Mon Sep 17 00:00:00 2001
From: Raphael Schweikert <any@sabberworm.com>
Date: Fri, 19 Oct 2018 09:28:07 +0200
Subject: [PATCH 02/13] Refactor parsing logic
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

• Extract parser state into its own instance
• Every type should be able to parse its own structure
---
 lib/Sabberworm/CSS/CSSList/CSSList.php        | 149 +++-
 lib/Sabberworm/CSS/CSSList/Document.php       |   8 +
 lib/Sabberworm/CSS/Parser.php                 | 788 +-----------------
 lib/Sabberworm/CSS/Parsing/ParserState.php    | 310 +++++++
 lib/Sabberworm/CSS/Property/AtRule.php        |   5 +-
 lib/Sabberworm/CSS/Rule/Rule.php              |  41 +-
 .../CSS/RuleSet/DeclarationBlock.php          |  13 +-
 lib/Sabberworm/CSS/RuleSet/RuleSet.php        |  41 +-
 lib/Sabberworm/CSS/Value/CSSString.php        |  34 +
 lib/Sabberworm/CSS/Value/CalcFunction.php     |  54 ++
 lib/Sabberworm/CSS/Value/Color.php            |  54 ++
 lib/Sabberworm/CSS/Value/LineName.php         |  23 +
 lib/Sabberworm/CSS/Value/Size.php             |  48 ++
 lib/Sabberworm/CSS/Value/URL.php              |  18 +
 lib/Sabberworm/CSS/Value/Value.php            | 118 ++-
 15 files changed, 902 insertions(+), 802 deletions(-)
 create mode 100644 lib/Sabberworm/CSS/Parsing/ParserState.php

diff --git a/lib/Sabberworm/CSS/CSSList/CSSList.php b/lib/Sabberworm/CSS/CSSList/CSSList.php
index bc90460b..20b1b6a0 100644
--- a/lib/Sabberworm/CSS/CSSList/CSSList.php
+++ b/lib/Sabberworm/CSS/CSSList/CSSList.php
@@ -2,11 +2,22 @@
 
 namespace Sabberworm\CSS\CSSList;
 
+use Sabberworm\CSS\Comment\Commentable;
+use Sabberworm\CSS\Parsing\ParserState;
+use Sabberworm\CSS\Parsing\SourceException;
+use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+use Sabberworm\CSS\Property\AtRule;
+use Sabberworm\CSS\Property\Charset;
+use Sabberworm\CSS\Property\CSSNamespace;
+use Sabberworm\CSS\Property\Import;
+use Sabberworm\CSS\Property\Selector;
 use Sabberworm\CSS\Renderable;
+use Sabberworm\CSS\RuleSet\AtRuleSet;
 use Sabberworm\CSS\RuleSet\DeclarationBlock;
 use Sabberworm\CSS\RuleSet\RuleSet;
-use Sabberworm\CSS\Property\Selector;
-use Sabberworm\CSS\Comment\Commentable;
+use Sabberworm\CSS\Value\CSSString;
+use Sabberworm\CSS\Value\URL;
+use Sabberworm\CSS\Value\Value;
 
 /**
  * A CSSList is the most generic container available. Its contents include RuleSet as well as other CSSList objects.
@@ -24,6 +35,140 @@ public function __construct($iLineNo = 0) {
 		$this->iLineNo = $iLineNo;
 	}
 
+	public static function parseList(ParserState $oParserState, CSSList $oList) {
+		$bIsRoot = $oList instanceof Document;
+		if(is_string($oParserState)) {
+			$oParserState = new ParserState($oParserState);
+		}
+		$bLenientParsing = $oParserState->getSettings()->bLenientParsing;
+		while(!$oParserState->isEnd()) {
+			$comments = $oParserState->consumeWhiteSpace();
+			$oListItem = null;
+			if($bLenientParsing) {
+				try {
+					$oListItem = self::parseListItem($oParserState, $oList);
+				} catch (UnexpectedTokenException $e) {
+					$oListItem = false;
+				}
+			} else {
+				$oListItem = self::parseListItem($oParserState, $oList);
+			}
+			if($oListItem === null) {
+				// List parsing finished
+				return;
+			}
+			if($oListItem) {
+				$oListItem->setComments($comments);
+				$oList->append($oListItem);
+			}
+			$oParserState->consumeWhiteSpace();
+		}
+		if(!$bIsRoot && !$bLenientParsing) {
+			throw new SourceException("Unexpected end of document", $oParserState->currentLine());
+		}
+	}
+
+	private static function parseListItem(ParserState $oParserState, CSSList $oList) {
+		$bIsRoot = $oList instanceof Document;
+		if ($oParserState->comes('@')) {
+			$oAtRule = self::parseAtRule($oParserState);
+			if($oAtRule instanceof Charset) {
+				if(!$bIsRoot) {
+					throw new UnexpectedTokenException('@charset may only occur in root document', '', 'custom', $oParserState->currentLine());
+				}
+				if(count($oList->getContents()) > 0) {
+					throw new UnexpectedTokenException('@charset must be the first parseable token in a document', '', 'custom', $oParserState->currentLine());
+				}
+				$oParserState->setCharset($oAtRule->getCharset()->getString());
+			}
+			return $oAtRule;
+		} else if ($oParserState->comes('}')) {
+			$oParserState->consume('}');
+			if ($bIsRoot) {
+				if ($oParserState->getSettings()->bLenientParsing) {
+					while ($oParserState->comes('}')) $oParserState->consume('}');
+					return DeclarationBlock::parse($oParserState);
+				} else {
+					throw new SourceException("Unopened {", $oParserState->currentLine());
+				}
+			} else {
+				return null;
+			}
+		} else {
+			return DeclarationBlock::parse($oParserState);
+		}
+	}
+
+	private static function parseAtRule(ParserState $oParserState) {
+		$oParserState->consume('@');
+		$sIdentifier = $oParserState->parseIdentifier();
+		$iIdentifierLineNum = $oParserState->currentLine();
+		$oParserState->consumeWhiteSpace();
+		if ($sIdentifier === 'import') {
+			$oLocation = URL::parse($oParserState);
+			$oParserState->consumeWhiteSpace();
+			$sMediaQuery = null;
+			if (!$oParserState->comes(';')) {
+				$sMediaQuery = $oParserState->consumeUntil(';');
+			}
+			$oParserState->consume(';');
+			return new Import($oLocation, $sMediaQuery, $iIdentifierLineNum);
+		} else if ($sIdentifier === 'charset') {
+			$sCharset = CSSString::parse($oParserState);
+			$oParserState->consumeWhiteSpace();
+			$oParserState->consume(';');
+			return new Charset($sCharset, $iIdentifierLineNum);
+		} else if (self::identifierIs($sIdentifier, 'keyframes')) {
+			$oResult = new KeyFrame($iIdentifierLineNum);
+			$oResult->setVendorKeyFrame($sIdentifier);
+			$oResult->setAnimationName(trim($oParserState->consumeUntil('{', false, true)));
+			CSSList::parseList($oParserState, $oResult);
+			return $oResult;
+		} else if ($sIdentifier === 'namespace') {
+			$sPrefix = null;
+			$mUrl = Value::parsePrimitiveValue($oParserState);
+			if (!$oParserState->comes(';')) {
+				$sPrefix = $mUrl;
+				$mUrl = Value::parsePrimitiveValue($oParserState);
+			}
+			$oParserState->consume(';');
+			if ($sPrefix !== null && !is_string($sPrefix)) {
+				throw new UnexpectedTokenException('Wrong namespace prefix', $sPrefix, 'custom', $iIdentifierLineNum);
+			}
+			if (!($mUrl instanceof CSSString || $mUrl instanceof URL)) {
+				throw new UnexpectedTokenException('Wrong namespace url of invalid type', $mUrl, 'custom', $iIdentifierLineNum);
+			}
+			return new CSSNamespace($mUrl, $sPrefix, $iIdentifierLineNum);
+		} else {
+			//Unknown other at rule (font-face or such)
+			$sArgs = trim($oParserState->consumeUntil('{', false, true));
+			$bUseRuleSet = true;
+			foreach(explode('/', AtRule::BLOCK_RULES) as $sBlockRuleName) {
+				if(self::identifierIs($sIdentifier, $sBlockRuleName)) {
+					$bUseRuleSet = false;
+					break;
+				}
+			}
+			if($bUseRuleSet) {
+				$oAtRule = new AtRuleSet($sIdentifier, $sArgs, $iIdentifierLineNum);
+				RuleSet::parseRuleSet($oParserState, $oAtRule);
+			} else {
+				$oAtRule = new AtRuleBlockList($sIdentifier, $sArgs, $iIdentifierLineNum);
+				CSSList::parseList($oParserState, $oAtRule);
+			}
+			return $oAtRule;
+		}
+	}
+
+		/**
+	 * Tests an identifier for a given value. Since identifiers are all keywords, they can be vendor-prefixed. We need to check for these versions too.
+	 */
+	private static function identifierIs($sIdentifier, $sMatch) {
+		return (strcasecmp($sIdentifier, $sMatch) === 0)
+			?: preg_match("/^(-\\w+-)?$sMatch$/i", $sIdentifier) === 1;
+	}
+
+
 	/**
 	 * @return int
 	 */
diff --git a/lib/Sabberworm/CSS/CSSList/Document.php b/lib/Sabberworm/CSS/CSSList/Document.php
index bd4a23ee..873df755 100644
--- a/lib/Sabberworm/CSS/CSSList/Document.php
+++ b/lib/Sabberworm/CSS/CSSList/Document.php
@@ -2,6 +2,8 @@
 
 namespace Sabberworm\CSS\CSSList;
 
+use Sabberworm\CSS\Parsing\ParserState;
+
 /**
  * The root CSSList of a parsed file. Contains all top-level css contents, mostly declaration blocks, but also any @-rules encountered.
  */
@@ -14,6 +16,12 @@ public function __construct($iLineNo = 0) {
 		parent::__construct($iLineNo);
 	}
 
+	public static function parse(ParserState $oParserState) {
+		$oDocument = new Document($oParserState->currentLine());
+		CSSList::parseList($oParserState, $oDocument);
+		return $oDocument;
+	}
+
 	/**
 	 * Gets all DeclarationBlock objects recursively.
 	 */
diff --git a/lib/Sabberworm/CSS/Parser.php b/lib/Sabberworm/CSS/Parser.php
index adc0d390..a50a3592 100644
--- a/lib/Sabberworm/CSS/Parser.php
+++ b/lib/Sabberworm/CSS/Parser.php
@@ -2,45 +2,18 @@
 
 namespace Sabberworm\CSS;
 
-use Sabberworm\CSS\CSSList\CSSList;
 use Sabberworm\CSS\CSSList\Document;
-use Sabberworm\CSS\CSSList\KeyFrame;
-use Sabberworm\CSS\Parsing\SourceException;
-use Sabberworm\CSS\Property\AtRule;
-use Sabberworm\CSS\Property\Import;
-use Sabberworm\CSS\Property\Charset;
-use Sabberworm\CSS\Property\CSSNamespace;
-use Sabberworm\CSS\RuleSet\AtRuleSet;
-use Sabberworm\CSS\CSSList\AtRuleBlockList;
-use Sabberworm\CSS\RuleSet\DeclarationBlock;
-use Sabberworm\CSS\Value\CSSFunction;
-use Sabberworm\CSS\Value\CalcFunction;
-use Sabberworm\CSS\Value\RuleValueList;
-use Sabberworm\CSS\Value\CalcRuleValueList;
-use Sabberworm\CSS\Value\Size;
-use Sabberworm\CSS\Value\Color;
-use Sabberworm\CSS\Value\URL;
-use Sabberworm\CSS\Value\CSSString;
-use Sabberworm\CSS\Value\LineName;
-use Sabberworm\CSS\Rule\Rule;
-use Sabberworm\CSS\Parsing\UnexpectedTokenException;
-use Sabberworm\CSS\Comment\Comment;
+use Sabberworm\CSS\Parsing\ParserState;
 
 /**
  * Parser class parses CSS from text into a data structure.
  */
 class Parser {
-
 	private $sText;
-	private $aText;
-	private $iCurrentPosition;
-	private $oParserSettings;
-	private $sCharset;
-	private $iLength;
-	private $blockRules;
-	private $aSizeUnits;
 	private $iLineNo;
 
+	private $oParserState;
+
 	/**
 	 * Parser constructor.
 	 * Note that that iLineNo starts from 1 and not 0
@@ -51,769 +24,24 @@ class Parser {
 	 */
 	public function __construct($sText, Settings $oParserSettings = null, $iLineNo = 1) {
 		$this->sText = $sText;
-		$this->iCurrentPosition = 0;
-		$this->iLineNo = $iLineNo;
 		if ($oParserSettings === null) {
 			$oParserSettings = Settings::create();
 		}
 		$this->oParserSettings = $oParserSettings;
-		$this->blockRules = explode('/', AtRule::BLOCK_RULES);
-
-		foreach (explode('/', Size::ABSOLUTE_SIZE_UNITS.'/'.Size::RELATIVE_SIZE_UNITS.'/'.Size::NON_SIZE_UNITS) as $val) {
-			$iSize = strlen($val);
-			if(!isset($this->aSizeUnits[$iSize])) {
-				$this->aSizeUnits[$iSize] = array();
-			}
-			$this->aSizeUnits[$iSize][strtolower($val)] = $val;
-		}
-		ksort($this->aSizeUnits, SORT_NUMERIC);
+		$this->iLineNo = $iLineNo;
 	}
 
 	public function setCharset($sCharset) {
-		$this->sCharset = $sCharset;
-		$this->aText = $this->strsplit($this->sText);
-		$this->iLength = count($this->aText);
+		$this->oParserHelper->setCharset($sCharset);
 	}
 
 	public function getCharset() {
-		return $this->sCharset;
+		$this->oParserHelper->getCharset();
 	}
 
 	public function parse() {
-		$this->setCharset($this->oParserSettings->sDefaultCharset);
-		$oResult = new Document($this->iLineNo);
-		$this->parseDocument($oResult);
-		return $oResult;
-	}
-
-	private function parseDocument(Document $oDocument) {
-		$this->parseList($oDocument, true);
-	}
-
-	private function parseList(CSSList $oList, $bIsRoot = false) {
-		while (!$this->isEnd()) {
-			$comments = $this->consumeWhiteSpace();
-			$oListItem = null;
-			if($this->oParserSettings->bLenientParsing) {
-				try {
-					$oListItem = $this->parseListItem($oList, $bIsRoot);
-				} catch (UnexpectedTokenException $e) {
-					$oListItem = false;
-				}
-			} else {
-				$oListItem = $this->parseListItem($oList, $bIsRoot);
-			}
-			if($oListItem === null) {
-				// List parsing finished
-				return;
-			}
-			if($oListItem) {
-				$oListItem->setComments($comments);
-				$oList->append($oListItem);
-			}
-			$this->consumeWhiteSpace();
-		}
-		if (!$bIsRoot && !$this->oParserSettings->bLenientParsing) {
-			throw new SourceException("Unexpected end of document", $this->iLineNo);
-		}
-	}
-	
-	private function parseListItem(CSSList $oList, $bIsRoot = false) {
-		if ($this->comes('@')) {
-			$oAtRule = $this->parseAtRule();
-			if($oAtRule instanceof Charset) {
-				if(!$bIsRoot) {
-					throw new UnexpectedTokenException('@charset may only occur in root document', '', 'custom', $this->iLineNo);
-				}
-				if(count($oList->getContents()) > 0) {
-					throw new UnexpectedTokenException('@charset must be the first parseable token in a document', '', 'custom', $this->iLineNo);
-				}
-				$this->setCharset($oAtRule->getCharset()->getString());
-			}
-			return $oAtRule;
-		} else if ($this->comes('}')) {
-			$this->consume('}');
-			if ($bIsRoot) {
-				if ($this->oParserSettings->bLenientParsing) {
-					while ($this->comes('}')) $this->consume('}');
-					return $this->parseSelector();
-				} else {
-					throw new SourceException("Unopened {", $this->iLineNo);
-				}
-			} else {
-				return null;
-			}
-		} else {
-			return $this->parseSelector();
-		}
-	}
-
-	private function parseAtRule() {
-		$this->consume('@');
-		$sIdentifier = $this->parseIdentifier(false);
-		$iIdentifierLineNum = $this->iLineNo;
-		$this->consumeWhiteSpace();
-		if ($sIdentifier === 'import') {
-			$oLocation = $this->parseURLValue();
-			$this->consumeWhiteSpace();
-			$sMediaQuery = null;
-			if (!$this->comes(';')) {
-				$sMediaQuery = $this->consumeUntil(';');
-			}
-			$this->consume(';');
-			return new Import($oLocation, $sMediaQuery, $iIdentifierLineNum);
-		} else if ($sIdentifier === 'charset') {
-			$sCharset = $this->parseStringValue();
-			$this->consumeWhiteSpace();
-			$this->consume(';');
-			return new Charset($sCharset, $iIdentifierLineNum);
-		} else if ($this->identifierIs($sIdentifier, 'keyframes')) {
-			$oResult = new KeyFrame($iIdentifierLineNum);
-			$oResult->setVendorKeyFrame($sIdentifier);
-			$oResult->setAnimationName(trim($this->consumeUntil('{', false, true)));
-			$this->parseList($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 UnexpectedTokenException('Wrong namespace prefix', $sPrefix, 'custom', $iIdentifierLineNum);
-			}
-			if (!($mUrl instanceof CSSString || $mUrl instanceof URL)) {
-				throw new UnexpectedTokenException('Wrong namespace url of invalid type', $mUrl, 'custom', $iIdentifierLineNum);
-			}
-			return new CSSNamespace($mUrl, $sPrefix, $iIdentifierLineNum);
-		} else {
-			//Unknown other at rule (font-face or such)
-			$sArgs = trim($this->consumeUntil('{', false, true));
-			$bUseRuleSet = true;
-			foreach($this->blockRules as $sBlockRuleName) {
-				if($this->identifierIs($sIdentifier, $sBlockRuleName)) {
-					$bUseRuleSet = false;
-					break;
-				}
-			}
-			if($bUseRuleSet) {
-				$oAtRule = new AtRuleSet($sIdentifier, $sArgs, $iIdentifierLineNum);
-				$this->parseRuleSet($oAtRule);
-			} else {
-				$oAtRule = new AtRuleBlockList($sIdentifier, $sArgs, $iIdentifierLineNum);
-				$this->parseList($oAtRule);
-			}
-			return $oAtRule;
-		}
-	}
-
-	private function parseIdentifier($bAllowFunctions = true, $bIgnoreCase = true) {
-		$sResult = $this->parseCharacter(true);
-		if ($sResult === null) {
-			throw new UnexpectedTokenException($sResult, $this->peek(5), 'identifier', $this->iLineNo);
-		}
-		$sCharacter = null;
-		while (($sCharacter = $this->parseCharacter(true)) !== null) {
-			$sResult .= $sCharacter;
-		}
-		if ($bIgnoreCase) {
-			$sResult = $this->strtolower($sResult);
-		}
-		if ($bAllowFunctions && $this->comes('(')) {
-			$this->consume('(');
-			$aArguments = $this->parseValue(array('=', ' ', ','));
-			$sResult = new CSSFunction($sResult, $aArguments, ',', $this->iLineNo);
-			$this->consume(')');
-		}
-		return $sResult;
-	}
-
-	private function parseStringValue() {
-		$sBegin = $this->peek();
-		$sQuote = null;
-		if ($sBegin === "'") {
-			$sQuote = "'";
-		} else if ($sBegin === '"') {
-			$sQuote = '"';
-		}
-		if ($sQuote !== null) {
-			$this->consume($sQuote);
-		}
-		$sResult = "";
-		$sContent = null;
-		if ($sQuote === null) {
-			//Unquoted strings end in whitespace or with braces, brackets, parentheses
-			while (!preg_match('/[\\s{}()<>\\[\\]]/isu', $this->peek())) {
-				$sResult .= $this->parseCharacter(false);
-			}
-		} else {
-			while (!$this->comes($sQuote)) {
-				$sContent = $this->parseCharacter(false);
-				if ($sContent === null) {
-					throw new SourceException("Non-well-formed quoted string {$this->peek(3)}", $this->iLineNo);
-				}
-				$sResult .= $sContent;
-			}
-			$this->consume($sQuote);
-		}
-		return new CSSString($sResult, $this->iLineNo);
-	}
-
-	private function parseCharacter($bIsForIdentifier) {
-		if ($this->peek() === '\\') {
-			if ($bIsForIdentifier && $this->oParserSettings->bLenientParsing && ($this->comes('\0') || $this->comes('\9'))) {
-				// Non-strings can contain \0 or \9 which is an IE hack supported in lenient parsing.
-				return null;
-			}
-			$this->consume('\\');
-			if ($this->comes('\n') || $this->comes('\r')) {
-				return '';
-			}
-			if (preg_match('/[0-9a-fA-F]/Su', $this->peek()) === 0) {
-				return $this->consume(1);
-			}
-			$sUnicode = $this->consumeExpression('/^[0-9a-fA-F]{1,6}/u', 6);
-			if ($this->strlen($sUnicode) < 6) {
-				//Consume whitespace after incomplete unicode escape
-				if (preg_match('/\\s/isSu', $this->peek())) {
-					if ($this->comes('\r\n')) {
-						$this->consume(2);
-					} else {
-						$this->consume(1);
-					}
-				}
-			}
-			$iUnicode = intval($sUnicode, 16);
-			$sUtf32 = "";
-			for ($i = 0; $i < 4; ++$i) {
-				$sUtf32 .= chr($iUnicode & 0xff);
-				$iUnicode = $iUnicode >> 8;
-			}
-			return iconv('utf-32le', $this->sCharset, $sUtf32);
-		}
-		if ($bIsForIdentifier) {
-			$peek = ord($this->peek());
-			// Ranges: a-z A-Z 0-9 - _
-			if (($peek >= 97 && $peek <= 122) ||
-				($peek >= 65 && $peek <= 90) ||
-				($peek >= 48 && $peek <= 57) ||
-				($peek === 45) ||
-				($peek === 95) ||
-				($peek > 0xa1)) {
-				return $this->consume(1);
-			}
-		} else {
-			return $this->consume(1);
-		}
-		return null;
-	}
-
-	private function parseSelector() {
-		$aComments = array();
-		$oResult = new DeclarationBlock($this->iLineNo);
-		$oResult->setSelector($this->consumeUntil('{', false, true, $aComments));
-		$oResult->setComments($aComments);
-		$this->parseRuleSet($oResult);
-		return $oResult;
-	}
-
-	private function parseRuleSet($oRuleSet) {
-		while ($this->comes(';')) {
-			$this->consume(';');
-		}
-		while (!$this->comes('}')) {
-			$oRule = null;
-			if($this->oParserSettings->bLenientParsing) {
-				try {
-					$oRule = $this->parseRule();
-				} catch (UnexpectedTokenException $e) {
-					try {
-						$sConsume = $this->consumeUntil(array("\n", ";", '}'), true);
-						// We need to “unfind” the matches to the end of the ruleSet as this will be matched later
-						if($this->streql(substr($sConsume, -1), '}')) {
-							--$this->iCurrentPosition;
-						} else {
-							while ($this->comes(';')) {
-								$this->consume(';');
-							}
-						}
-					} catch (UnexpectedTokenException $e) {
-						// We’ve reached the end of the document. Just close the RuleSet.
-						return;
-					}
-				}
-			} else {
-				$oRule = $this->parseRule();
-			}
-			if($oRule) {
-				$oRuleSet->addRule($oRule);
-			}
-		}
-		$this->consume('}');
-	}
-
-	private function parseRule() {
-		$aComments = $this->consumeWhiteSpace();
-		$oRule = new Rule($this->parseIdentifier(), $this->iLineNo);
-		$oRule->setComments($aComments);
-		$oRule->addComments($this->consumeWhiteSpace());
-		$this->consume(':');
-		$oValue = $this->parseValue(self::listDelimiterForRule($oRule->getRule()));
-		$oRule->setValue($oValue);
-		if ($this->oParserSettings->bLenientParsing) {
-			while ($this->comes('\\')) {
-				$this->consume('\\');
-				$oRule->addIeHack($this->consume());
-				$this->consumeWhiteSpace();
-			}
-		}
-		$this->consumeWhiteSpace();
-		if ($this->comes('!')) {
-			$this->consume('!');
-			$this->consumeWhiteSpace();
-			$this->consume('important');
-			$oRule->setIsImportant(true);
-		}
-		$this->consumeWhiteSpace();
-		while ($this->comes(';')) {
-			$this->consume(';');
-		}
-		$this->consumeWhiteSpace();
-		return $oRule;
-	}
-
-	private function parseValue($aListDelimiters) {
-		$aStack = array();
-		$this->consumeWhiteSpace();
-		//Build a list of delimiters and parsed values
-		while (!($this->comes('}') || $this->comes(';') || $this->comes('!') || $this->comes(')') || $this->comes('\\'))) {
-			if (count($aStack) > 0) {
-				$bFoundDelimiter = false;
-				foreach ($aListDelimiters as $sDelimiter) {
-					if ($this->comes($sDelimiter)) {
-						array_push($aStack, $this->consume($sDelimiter));
-						$this->consumeWhiteSpace();
-						$bFoundDelimiter = true;
-						break;
-					}
-				}
-				if (!$bFoundDelimiter) {
-					//Whitespace was the list delimiter
-					array_push($aStack, ' ');
-				}
-			}
-			array_push($aStack, $this->parsePrimitiveValue());
-			$this->consumeWhiteSpace();
-		}
-		//Convert the list to list objects
-		foreach ($aListDelimiters as $sDelimiter) {
-			if (count($aStack) === 1) {
-				return $aStack[0];
-			}
-			$iStartPosition = null;
-			while (($iStartPosition = array_search($sDelimiter, $aStack, true)) !== false) {
-				$iLength = 2; //Number of elements to be joined
-				for ($i = $iStartPosition + 2; $i < count($aStack); $i+=2, ++$iLength) {
-					if ($sDelimiter !== $aStack[$i]) {
-						break;
-					}
-				}
-				$oList = new RuleValueList($sDelimiter, $this->iLineNo);
-				for ($i = $iStartPosition - 1; $i - $iStartPosition + 1 < $iLength * 2; $i+=2) {
-					$oList->addListComponent($aStack[$i]);
-				}
-				array_splice($aStack, $iStartPosition - 1, $iLength * 2 - 1, array($oList));
-			}
-		}
-		return $aStack[0];
-	}
-
-	private static function listDelimiterForRule($sRule) {
-		if (preg_match('/^font($|-)/', $sRule)) {
-			return array(',', '/', ' ');
-		}
-		return array(',', ' ', '/');
-	}
-
-	private function parsePrimitiveValue() {
-		$oValue = null;
-		$this->consumeWhiteSpace();
-		if (is_numeric($this->peek()) || ($this->comes('-.') && is_numeric($this->peek(1, 2))) || (($this->comes('-') || $this->comes('.')) && is_numeric($this->peek(1, 1)))) {
-			$oValue = $this->parseNumericValue();
-		} else if ($this->comes('#') || $this->comes('rgb', true) || $this->comes('hsl', true)) {
-			$oValue = $this->parseColorValue();
-		} else if ($this->comes('url', true)) {
-			$oValue = $this->parseURLValue();
-		} else if ($this->comes('calc', true) || $this->comes('-webkit-calc', true) || $this->comes('-moz-calc', true)) {
-			$oValue = $this->parseCalcValue();
-		} else if ($this->comes("'") || $this->comes('"')) {
-			$oValue = $this->parseStringValue();
-		} else if ($this->comes("progid:") && $this->oParserSettings->bLenientParsing) {
-			$oValue = $this->parseMicrosoftFilter();
-		} else if ($this->comes("[")) {
-			$oValue = $this->parseLineNameValue();
-		} else {
-			$oValue = $this->parseIdentifier(true, false);
-		}
-		$this->consumeWhiteSpace();
-		return $oValue;
-	}
-
-	private function parseNumericValue($bForColor = false) {
-		$sSize = '';
-		if ($this->comes('-')) {
-			$sSize .= $this->consume('-');
-		}
-		while (is_numeric($this->peek()) || $this->comes('.')) {
-			if ($this->comes('.')) {
-				$sSize .= $this->consume('.');
-			} else {
-				$sSize .= $this->consume(1);
-			}
-		}
-
-		$sUnit = null;
-		foreach ($this->aSizeUnits as $iLength => &$aValues) {
-			$sKey = strtolower($this->peek($iLength));
-			if(array_key_exists($sKey, $aValues)) {
-				if (($sUnit = $aValues[$sKey]) !== null) {
-					$this->consume($iLength);
-					break;
-				}
-			}
-		}
-		return new Size(floatval($sSize), $sUnit, $bForColor, $this->iLineNo);
-	}
-
-	private function parseLineNameValue() {
-		$this->consume('[');
-		$this->consumeWhiteSpace();
-		$aNames = array();
-		do {
-			if($this->oParserSettings->bLenientParsing) {
-				try {
-					$aNames[] = $this->parseIdentifier(false, true);
-				} catch(UnexpectedTokenException $e) {}
-			} else {
-				$aNames[] = $this->parseIdentifier(false, true);
-			}
-			$this->consumeWhiteSpace();
-		} while (!$this->comes(']'));
-		$this->consume(']');
-		return new LineName($aNames, $this->iLineNo);
-	}
-
-	private function parseColorValue() {
-		$aColor = array();
-		if ($this->comes('#')) {
-			$this->consume('#');
-			$sValue = $this->parseIdentifier(false);
-			if ($this->strlen($sValue) === 3) {
-				$sValue = $sValue[0] . $sValue[0] . $sValue[1] . $sValue[1] . $sValue[2] . $sValue[2];
-			} else if ($this->strlen($sValue) === 4) {
-				$sValue = $sValue[0] . $sValue[0] . $sValue[1] . $sValue[1] . $sValue[2] . $sValue[2] . $sValue[3] . $sValue[3];
-			}
-
-			if ($this->strlen($sValue) === 8) {
-				$aColor = array('r' => new Size(intval($sValue[0] . $sValue[1], 16), null, true, $this->iLineNo), 'g' => new Size(intval($sValue[2] . $sValue[3], 16), null, true, $this->iLineNo), 'b' => new Size(intval($sValue[4] . $sValue[5], 16), null, true, $this->iLineNo), 'a' => new Size(round($this->mapRange(intval($sValue[6] . $sValue[7], 16), 0, 255, 0, 1), 2), null, true, $this->iLineNo));
-			} else {
-				$aColor = array('r' => new Size(intval($sValue[0] . $sValue[1], 16), null, true, $this->iLineNo), 'g' => new Size(intval($sValue[2] . $sValue[3], 16), null, true, $this->iLineNo), 'b' => new Size(intval($sValue[4] . $sValue[5], 16), null, true, $this->iLineNo));
-			}
-		} else {
-			$sColorMode = $this->parseIdentifier(false);
-			$this->consumeWhiteSpace();
-			$this->consume('(');
-			$iLength = $this->strlen($sColorMode);
-			for ($i = 0; $i < $iLength; ++$i) {
-				$this->consumeWhiteSpace();
-				$aColor[$sColorMode[$i]] = $this->parseNumericValue(true);
-				$this->consumeWhiteSpace();
-				if ($i < ($iLength - 1)) {
-					$this->consume(',');
-				}
-			}
-			$this->consume(')');
-		}
-		return new Color($aColor, $this->iLineNo);
-	}
-
-	private function parseMicrosoftFilter() {
-		$sFunction = $this->consumeUntil('(', false, true);
-		$aArguments = $this->parseValue(array(',', '='));
-		return new CSSFunction($sFunction, $aArguments, ',', $this->iLineNo);
-	}
-
-	private function parseURLValue() {
-		$bUseUrl = $this->comes('url', true);
-		if ($bUseUrl) {
-			$this->consume('url');
-			$this->consumeWhiteSpace();
-			$this->consume('(');
-		}
-		$this->consumeWhiteSpace();
-		$oResult = new URL($this->parseStringValue(), $this->iLineNo);
-		if ($bUseUrl) {
-			$this->consumeWhiteSpace();
-			$this->consume(')');
-		}
-		return $oResult;
-	}
-
-	private function parseCalcValue() {
-		$aOperators = array('+', '-', '*', '/');
-		$sFunction = trim($this->consumeUntil('(', false, true));
-		$oCalcList = new CalcRuleValueList($this->iLineNo);
-		$oList = new RuleValueList(',', $this->iLineNo);
-		$iNestingLevel = 0;
-		$iLastComponentType = NULL;
-		while(!$this->comes(')') || $iNestingLevel > 0) {
-			$this->consumeWhiteSpace();
-			if ($this->comes('(')) {
-				$iNestingLevel++;
-				$oCalcList->addListComponent($this->consume(1));
-				continue;
-			} else if ($this->comes(')')) {
-				$iNestingLevel--;
-				$oCalcList->addListComponent($this->consume(1));
-				continue;
-			}
-			if ($iLastComponentType != CalcFunction::T_OPERAND) {
-				$oVal = $this->parsePrimitiveValue();
-				$oCalcList->addListComponent($oVal);
-				$iLastComponentType = CalcFunction::T_OPERAND;
-			} else {
-				if (in_array($this->peek(), $aOperators)) {
-					if (($this->comes('-') || $this->comes('+'))) {
-						if ($this->peek(1, -1) != ' ' || !($this->comes('- ') || $this->comes('+ '))) {
-							throw new UnexpectedTokenException(" {$this->peek()} ", $this->peek(1, -1) . $this->peek(2), 'literal', $this->iLineNo);
-						}
-					}
-					$oCalcList->addListComponent($this->consume(1));
-					$iLastComponentType = CalcFunction::T_OPERATOR;
-				} else {
-					throw new UnexpectedTokenException(sprintf('Next token was expected to be an operand of type %s. Instead "%s" was found.', implode(', ', $aOperators), $oVal), '', 'custom', $this->iLineNo);
-				}
-			}
-		}
-		$oList->addListComponent($oCalcList);
-		$this->consume(')');
-		return new CalcFunction($sFunction, $oList, ',', $this->iLineNo);
-	}
-
-	/**
-	 * Tests an identifier for a given value. Since identifiers are all keywords, they can be vendor-prefixed. We need to check for these versions too.
-	 */
-	private function identifierIs($sIdentifier, $sMatch) {
-		return (strcasecmp($sIdentifier, $sMatch) === 0)
-			?: preg_match("/^(-\\w+-)?$sMatch$/i", $sIdentifier) === 1;
-	}
-
-	private function comes($sString, $bCaseInsensitive = false) {
-		$sPeek = $this->peek(strlen($sString));
-		return ($sPeek == '')
-			? false
-			: $this->streql($sPeek, $sString, $bCaseInsensitive);
-	}
-
-	private function peek($iLength = 1, $iOffset = 0) {
-		$iOffset += $this->iCurrentPosition;
-		if ($iOffset >= $this->iLength) {
-			return '';
-		}
-		return $this->substr($iOffset, $iLength);
-	}
-
-	private function consume($mValue = 1) {
-		if (is_string($mValue)) {
-			$iLineCount = substr_count($mValue, "\n");
-			$iLength = $this->strlen($mValue);
-			if (!$this->streql($this->substr($this->iCurrentPosition, $iLength), $mValue)) {
-				throw new UnexpectedTokenException($mValue, $this->peek(max($iLength, 5)), $this->iLineNo);
-			}
-			$this->iLineNo += $iLineCount;
-			$this->iCurrentPosition += $this->strlen($mValue);
-			return $mValue;
-		} else {
-			if ($this->iCurrentPosition + $mValue > $this->iLength) {
-				throw new UnexpectedTokenException($mValue, $this->peek(5), 'count', $this->iLineNo);
-			}
-			$sResult = $this->substr($this->iCurrentPosition, $mValue);
-			$iLineCount = substr_count($sResult, "\n");
-			$this->iLineNo += $iLineCount;
-			$this->iCurrentPosition += $mValue;
-			return $sResult;
-		}
-	}
-
-	private function consumeExpression($mExpression, $iMaxLength = null) {
-		$aMatches = null;
-		$sInput = $iMaxLength !== null ? $this->peek($iMaxLength) : $this->inputLeft();
-		if (preg_match($mExpression, $sInput, $aMatches, PREG_OFFSET_CAPTURE) === 1) {
-			return $this->consume($aMatches[0][0]);
-		}
-		throw new UnexpectedTokenException($mExpression, $this->peek(5), 'expression', $this->iLineNo);
-	}
-
-	private function consumeWhiteSpace() {
-		$comments = array();
-		do {
-			while (preg_match('/\\s/isSu', $this->peek()) === 1) {
-				$this->consume(1);
-			}
-			if($this->oParserSettings->bLenientParsing) {
-				try {
-					$oComment = $this->consumeComment();
-				} catch(UnexpectedTokenException $e) {
-					// When we can’t find the end of a comment, we assume the document is finished.
-					$this->iCurrentPosition = $this->iLength;
-					return;
-				}
-			} else {
-				$oComment = $this->consumeComment();
-			}
-			if ($oComment !== false) {
-				$comments[] = $oComment;
-			}
-		} while($oComment !== false);
-		return $comments;
-	}
-
-	/**
-	 * @return false|Comment
-	 */
-	private function consumeComment() {
-		$mComment = false;
-		if ($this->comes('/*')) {
-			$iLineNo = $this->iLineNo;
-			$this->consume(1);
-			$mComment = '';
-			while (($char = $this->consume(1)) !== '') {
-				$mComment .= $char;
-				if ($this->comes('*/')) {
-					$this->consume(2);
-					break;
-				}
-			}
-		}
-
-		if ($mComment !== false) {
-			// We skip the * which was included in the comment.
-			return new Comment(substr($mComment, 1), $iLineNo);
-		}
-
-		return $mComment;
-	}
-
-	private function isEnd() {
-		return $this->iCurrentPosition >= $this->iLength;
-	}
-
-	private function consumeUntil($aEnd, $bIncludeEnd = false, $consumeEnd = false, array &$comments = array()) {
-		$aEnd = is_array($aEnd) ? $aEnd : array($aEnd);
-		$out = '';
-		$start = $this->iCurrentPosition;
-
-		while (($char = $this->consume(1)) !== '') {
-			if (in_array($char, $aEnd)) {
-				if ($bIncludeEnd) {
-					$out .= $char;
-				} elseif (!$consumeEnd) {
-					$this->iCurrentPosition -= $this->strlen($char);
-				}
-				return $out;
-			}
-			$out .= $char;
-			if ($comment = $this->consumeComment()) {
-				$comments[] = $comment;
-			}
-		}
-
-		$this->iCurrentPosition = $start;
-		throw new UnexpectedTokenException('One of ("'.implode('","', $aEnd).'")', $this->peek(5), 'search', $this->iLineNo);
-	}
-
-	private function inputLeft() {
-		return $this->substr($this->iCurrentPosition, -1);
-	}
-
-	private function substr($iStart, $iLength) {
-		if ($iLength < 0) {
-			$iLength = $this->iLength - $iStart + $iLength;
-		}
-		if ($iStart + $iLength > $this->iLength) {
-			$iLength = $this->iLength - $iStart;
-		}
-		$sResult = '';
-		while ($iLength > 0) {
-			$sResult .= $this->aText[$iStart];
-			$iStart++;
-			$iLength--;
-		}
-		return $sResult;
-	}
-
-	private function strlen($sString) {
-		if ($this->oParserSettings->bMultibyteSupport) {
-			return mb_strlen($sString, $this->sCharset);
-		} else {
-			return strlen($sString);
-		}
-	}
-
-	private function streql($sString1, $sString2, $bCaseInsensitive = true) {
-		if($bCaseInsensitive) {
-			return $this->strtolower($sString1) === $this->strtolower($sString2);
-		} else {
-			return $sString1 === $sString2;
-		}
-	}
-
-	private function strtolower($sString) {
-		if ($this->oParserSettings->bMultibyteSupport) {
-			return mb_strtolower($sString, $this->sCharset);
-		} else {
-			return strtolower($sString);
-		}
-	}
-
-	private function strsplit($sString) {
-		if ($this->oParserSettings->bMultibyteSupport) {
-			if ($this->streql($this->sCharset, 'utf-8')) {
-				return preg_split('//u', $sString, null, PREG_SPLIT_NO_EMPTY);
-			} else {
-				$iLength = mb_strlen($sString, $this->sCharset);
-				$aResult = array();
-				for ($i = 0; $i < $iLength; ++$i) {
-					$aResult[] = mb_substr($sString, $i, 1, $this->sCharset);
-				}
-				return $aResult;
-			}
-		} else {
-			if($sString === '') {
-				return array();
-			} else {
-				return str_split($sString);
-			}
-		}
-	}
-
-	private function strpos($sString, $sNeedle, $iOffset) {
-		if ($this->oParserSettings->bMultibyteSupport) {
-			return mb_strpos($sString, $sNeedle, $iOffset, $this->sCharset);
-		} else {
-			return strpos($sString, $sNeedle, $iOffset);
-		}
-	}
-
-	private function mapRange($fVal, $fFromMin, $fFromMax, $fToMin, $fToMax) {
-		$fFromRange = $fFromMax - $fFromMin;
-		$fToRange = $fToMax - $fToMin;
-		$fMultiplier = $fToRange / $fFromRange;
-		$fNewVal = $fVal - $fFromMin;
-		$fNewVal *= $fMultiplier;
-		return $fNewVal + $fToMin;
+		$this->oParserState = new ParserState($this->sText, $this->oParserSettings);
+		return Document::parse($this->oParserState);
 	}
 
 }
diff --git a/lib/Sabberworm/CSS/Parsing/ParserState.php b/lib/Sabberworm/CSS/Parsing/ParserState.php
new file mode 100644
index 00000000..4305c9a0
--- /dev/null
+++ b/lib/Sabberworm/CSS/Parsing/ParserState.php
@@ -0,0 +1,310 @@
+<?php
+namespace Sabberworm\CSS\Parsing;
+
+use Sabberworm\CSS\Comment\Comment;
+use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+use Sabberworm\CSS\Settings;
+
+class ParserState {
+	private $oParserSettings;
+
+	private $sText;
+
+	private $aText;
+	private $iCurrentPosition;
+	private $sCharset;
+	private $iLength;
+	private $iLineNo;
+
+	public function __construct($sText, Settings $oParserSettings, $iLineNo = 1) {
+		$this->oParserSettings = $oParserSettings;
+		$this->sText = $sText;
+		$this->iCurrentPosition = 0;
+		$this->iLineNo = $iLineNo;
+		$this->setCharset($this->oParserSettings->sDefaultCharset);
+	}
+
+	public function setCharset($sCharset) {
+		$this->sCharset = $sCharset;
+		$this->aText = $this->strsplit($this->sText);
+		$this->iLength = count($this->aText);
+	}
+
+	public function getCharset() {
+		$this->oParserHelper->getCharset();
+		return $this->sCharset;
+	}
+
+	public function currentLine() {
+		return $this->iLineNo;
+	}
+
+	public function getSettings() {
+		return $this->oParserSettings;
+	}
+
+	public function parseIdentifier($bIgnoreCase = true) {
+		$sResult = $this->parseCharacter(true);
+		if ($sResult === null) {
+			throw new UnexpectedTokenException($sResult, $this->peek(5), 'identifier', $this->iLineNo);
+		}
+		$sCharacter = null;
+		while (($sCharacter = $this->parseCharacter(true)) !== null) {
+			$sResult .= $sCharacter;
+		}
+		if ($bIgnoreCase) {
+			$sResult = $this->strtolower($sResult);
+		}
+		return $sResult;
+	}
+
+	public function parseCharacter($bIsForIdentifier) {
+		if ($this->peek() === '\\') {
+			if ($bIsForIdentifier && $this->oParserSettings->bLenientParsing && ($this->comes('\0') || $this->comes('\9'))) {
+				// Non-strings can contain \0 or \9 which is an IE hack supported in lenient parsing.
+				return null;
+			}
+			$this->consume('\\');
+			if ($this->comes('\n') || $this->comes('\r')) {
+				return '';
+			}
+			if (preg_match('/[0-9a-fA-F]/Su', $this->peek()) === 0) {
+				return $this->consume(1);
+			}
+			$sUnicode = $this->consumeExpression('/^[0-9a-fA-F]{1,6}/u', 6);
+			if ($this->strlen($sUnicode) < 6) {
+				//Consume whitespace after incomplete unicode escape
+				if (preg_match('/\\s/isSu', $this->peek())) {
+					if ($this->comes('\r\n')) {
+						$this->consume(2);
+					} else {
+						$this->consume(1);
+					}
+				}
+			}
+			$iUnicode = intval($sUnicode, 16);
+			$sUtf32 = "";
+			for ($i = 0; $i < 4; ++$i) {
+				$sUtf32 .= chr($iUnicode & 0xff);
+				$iUnicode = $iUnicode >> 8;
+			}
+			return iconv('utf-32le', $this->sCharset, $sUtf32);
+		}
+		if ($bIsForIdentifier) {
+			$peek = ord($this->peek());
+			// Ranges: a-z A-Z 0-9 - _
+			if (($peek >= 97 && $peek <= 122) ||
+				($peek >= 65 && $peek <= 90) ||
+				($peek >= 48 && $peek <= 57) ||
+				($peek === 45) ||
+				($peek === 95) ||
+				($peek > 0xa1)) {
+				return $this->consume(1);
+			}
+		} else {
+			return $this->consume(1);
+		}
+		return null;
+	}
+
+	public function consumeWhiteSpace() {
+		$comments = array();
+		do {
+			while (preg_match('/\\s/isSu', $this->peek()) === 1) {
+				$this->consume(1);
+			}
+			if($this->oParserSettings->bLenientParsing) {
+				try {
+					$oComment = $this->consumeComment();
+				} catch(UnexpectedTokenException $e) {
+					// When we can’t find the end of a comment, we assume the document is finished.
+					$this->iCurrentPosition = $this->iLength;
+					return;
+				}
+			} else {
+				$oComment = $this->consumeComment();
+			}
+			if ($oComment !== false) {
+				$comments[] = $oComment;
+			}
+		} while($oComment !== false);
+		return $comments;
+	}
+
+	public function comes($sString, $bCaseInsensitive = false) {
+		$sPeek = $this->peek(strlen($sString));
+		return ($sPeek == '')
+			? false
+			: $this->streql($sPeek, $sString, $bCaseInsensitive);
+	}
+
+	public function peek($iLength = 1, $iOffset = 0) {
+		$iOffset += $this->iCurrentPosition;
+		if ($iOffset >= $this->iLength) {
+			return '';
+		}
+		return $this->substr($iOffset, $iLength);
+	}
+
+	public function consume($mValue = 1) {
+		if (is_string($mValue)) {
+			$iLineCount = substr_count($mValue, "\n");
+			$iLength = $this->strlen($mValue);
+			if (!$this->streql($this->substr($this->iCurrentPosition, $iLength), $mValue)) {
+				throw new UnexpectedTokenException($mValue, $this->peek(max($iLength, 5)), $this->iLineNo);
+			}
+			$this->iLineNo += $iLineCount;
+			$this->iCurrentPosition += $this->strlen($mValue);
+			return $mValue;
+		} else {
+			if ($this->iCurrentPosition + $mValue > $this->iLength) {
+				throw new UnexpectedTokenException($mValue, $this->peek(5), 'count', $this->iLineNo);
+			}
+			$sResult = $this->substr($this->iCurrentPosition, $mValue);
+			$iLineCount = substr_count($sResult, "\n");
+			$this->iLineNo += $iLineCount;
+			$this->iCurrentPosition += $mValue;
+			return $sResult;
+		}
+	}
+
+	public function consumeExpression($mExpression, $iMaxLength = null) {
+		$aMatches = null;
+		$sInput = $iMaxLength !== null ? $this->peek($iMaxLength) : $this->inputLeft();
+		if (preg_match($mExpression, $sInput, $aMatches, PREG_OFFSET_CAPTURE) === 1) {
+			return $this->consume($aMatches[0][0]);
+		}
+		throw new UnexpectedTokenException($mExpression, $this->peek(5), 'expression', $this->iLineNo);
+	}
+
+	/**
+	 * @return false|Comment
+	 */
+	public function consumeComment() {
+		$mComment = false;
+		if ($this->comes('/*')) {
+			$iLineNo = $this->iLineNo;
+			$this->consume(1);
+			$mComment = '';
+			while (($char = $this->consume(1)) !== '') {
+				$mComment .= $char;
+				if ($this->comes('*/')) {
+					$this->consume(2);
+					break;
+				}
+			}
+		}
+
+		if ($mComment !== false) {
+			// We skip the * which was included in the comment.
+			return new Comment(substr($mComment, 1), $iLineNo);
+		}
+
+		return $mComment;
+	}
+
+	public function isEnd() {
+		return $this->iCurrentPosition >= $this->iLength;
+	}
+
+	public function consumeUntil($aEnd, $bIncludeEnd = false, $consumeEnd = false, array &$comments = array()) {
+		$aEnd = is_array($aEnd) ? $aEnd : array($aEnd);
+		$out = '';
+		$start = $this->iCurrentPosition;
+
+		while (($char = $this->consume(1)) !== '') {
+			if (in_array($char, $aEnd)) {
+				if ($bIncludeEnd) {
+					$out .= $char;
+				} elseif (!$consumeEnd) {
+					$this->iCurrentPosition -= $this->strlen($char);
+				}
+				return $out;
+			}
+			$out .= $char;
+			if ($comment = $this->consumeComment()) {
+				$comments[] = $comment;
+			}
+		}
+
+		$this->iCurrentPosition = $start;
+		throw new UnexpectedTokenException('One of ("'.implode('","', $aEnd).'")', $this->peek(5), 'search', $this->iLineNo);
+	}
+
+	private function inputLeft() {
+		return $this->substr($this->iCurrentPosition, -1);
+	}
+
+	public function streql($sString1, $sString2, $bCaseInsensitive = true) {
+		if($bCaseInsensitive) {
+			return $this->strtolower($sString1) === $this->strtolower($sString2);
+		} else {
+			return $sString1 === $sString2;
+		}
+	}
+
+	public function backtrack($iAmount) {
+		$this->iCurrentPosition -= $iAmount;
+	}
+
+	public function strlen($sString) {
+		if ($this->oParserSettings->bMultibyteSupport) {
+			return mb_strlen($sString, $this->sCharset);
+		} else {
+			return strlen($sString);
+		}	
+	}	
+
+	private function substr($iStart, $iLength) {
+		if ($iLength < 0) {
+			$iLength = $this->iLength - $iStart + $iLength;
+		}	
+		if ($iStart + $iLength > $this->iLength) {
+			$iLength = $this->iLength - $iStart;
+		}	
+		$sResult = '';
+		while ($iLength > 0) {
+			$sResult .= $this->aText[$iStart];
+			$iStart++;
+			$iLength--;
+		}	
+		return $sResult;
+	}
+
+	private function strtolower($sString) {
+		if ($this->oParserSettings->bMultibyteSupport) {
+			return mb_strtolower($sString, $this->sCharset);
+		} else {
+			return strtolower($sString);
+		}
+	}
+
+	private function strsplit($sString) {
+		if ($this->oParserSettings->bMultibyteSupport) {
+			if ($this->streql($this->sCharset, 'utf-8')) {
+				return preg_split('//u', $sString, null, PREG_SPLIT_NO_EMPTY);
+			} else {
+				$iLength = mb_strlen($sString, $this->sCharset);
+				$aResult = array();
+				for ($i = 0; $i < $iLength; ++$i) {
+					$aResult[] = mb_substr($sString, $i, 1, $this->sCharset);
+				}
+				return $aResult;
+			}
+		} else {
+			if($sString === '') {
+				return array();
+			} else {
+				return str_split($sString);
+			}
+		}
+	}
+
+	private function strpos($sString, $sNeedle, $iOffset) {
+		if ($this->oParserSettings->bMultibyteSupport) {
+			return mb_strpos($sString, $sNeedle, $iOffset, $this->sCharset);
+		} else {
+			return strpos($sString, $sNeedle, $iOffset);
+		}
+	}
+}
\ No newline at end of file
diff --git a/lib/Sabberworm/CSS/Property/AtRule.php b/lib/Sabberworm/CSS/Property/AtRule.php
index de3eea19..b20c8c6e 100644
--- a/lib/Sabberworm/CSS/Property/AtRule.php
+++ b/lib/Sabberworm/CSS/Property/AtRule.php
@@ -6,9 +6,10 @@
 use Sabberworm\CSS\Comment\Commentable;
 
 interface AtRule extends Renderable, Commentable {
-	const BLOCK_RULES = 'media/document/supports/region-style/font-feature-values';
 	// Since there are more set rules than block rules, we’re whitelisting the block rules and have anything else be treated as a set rule.
-	const SET_RULES = 'font-face/counter-style/page/swash/styleset/annotation'; //…and more font-specific ones (to be used inside font-feature-values)
+	const BLOCK_RULES = 'media/document/supports/region-style/font-feature-values';
+	// …and more font-specific ones (to be used inside font-feature-values)
+	const SET_RULES = 'font-face/counter-style/page/swash/styleset/annotation';
 	
 	public function atRuleName();
 	public function atRuleArgs();
diff --git a/lib/Sabberworm/CSS/Rule/Rule.php b/lib/Sabberworm/CSS/Rule/Rule.php
index 3e485375..3fa031bd 100644
--- a/lib/Sabberworm/CSS/Rule/Rule.php
+++ b/lib/Sabberworm/CSS/Rule/Rule.php
@@ -2,10 +2,11 @@
 
 namespace Sabberworm\CSS\Rule;
 
+use Sabberworm\CSS\Comment\Commentable;
+use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Renderable;
 use Sabberworm\CSS\Value\RuleValueList;
 use Sabberworm\CSS\Value\Value;
-use Sabberworm\CSS\Comment\Commentable;
 
 /**
  * RuleSets contains Rule objects which always have a key and a value.
@@ -29,6 +30,44 @@ public function __construct($sRule, $iLineNo = 0) {
 		$this->aComments = array();
 	}
 
+	public static function parse(ParserState $oParserState) {
+		$aComments = $oParserState->consumeWhiteSpace();
+		$oRule = new Rule($oParserState->parseIdentifier(), $oParserState->currentLine());
+		$oRule->setComments($aComments);
+		$oRule->addComments($oParserState->consumeWhiteSpace());
+		$oParserState->consume(':');
+		$oValue = Value::parseValue($oParserState, self::listDelimiterForRule($oRule->getRule()));
+		$oRule->setValue($oValue);
+		if ($oParserState->getSettings()->bLenientParsing) {
+			while ($oParserState->comes('\\')) {
+				$oParserState->consume('\\');
+				$oRule->addIeHack($oParserState->consume());
+				$oParserState->consumeWhiteSpace();
+			}
+		}
+		$oParserState->consumeWhiteSpace();
+		if ($oParserState->comes('!')) {
+			$oParserState->consume('!');
+			$oParserState->consumeWhiteSpace();
+			$oParserState->consume('important');
+			$oRule->setIsImportant(true);
+		}
+		$oParserState->consumeWhiteSpace();
+		while ($oParserState->comes(';')) {
+			$oParserState->consume(';');
+		}
+		$oParserState->consumeWhiteSpace();
+
+		return $oRule;
+	}
+
+	private static function listDelimiterForRule($sRule) {
+		if (preg_match('/^font($|-)/', $sRule)) {
+			return array(',', '/', ' ');
+		}
+		return array(',', ' ', '/');
+	}
+
 	/**
 	 * @return int
 	 */
diff --git a/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php b/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
index e18f5d82..451eaa7e 100644
--- a/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
+++ b/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
@@ -2,6 +2,8 @@
 
 namespace Sabberworm\CSS\RuleSet;
 
+use Sabberworm\CSS\Parsing\ParserState;
+use Sabberworm\CSS\Parsing\OutputException;
 use Sabberworm\CSS\Property\Selector;
 use Sabberworm\CSS\Rule\Rule;
 use Sabberworm\CSS\Value\RuleValueList;
@@ -9,7 +11,6 @@
 use Sabberworm\CSS\Value\Size;
 use Sabberworm\CSS\Value\Color;
 use Sabberworm\CSS\Value\URL;
-use Sabberworm\CSS\Parsing\OutputException;
 
 /**
  * Declaration blocks are the parts of a css file which denote the rules belonging to a selector.
@@ -24,6 +25,16 @@ public function __construct($iLineNo = 0) {
 		$this->aSelectors = array();
 	}
 
+	public static function parse(ParserState $oParserState) {
+		$aComments = array();
+		$oResult = new DeclarationBlock($oParserState->currentLine());
+		$oResult->setSelector($oParserState->consumeUntil('{', false, true, $aComments));
+		$oResult->setComments($aComments);
+		RuleSet::parseRuleSet($oParserState, $oResult);
+		return $oResult;
+	}
+
+
 	public function setSelectors($mSelector) {
 		if (is_array($mSelector)) {
 			$this->aSelectors = $mSelector;
diff --git a/lib/Sabberworm/CSS/RuleSet/RuleSet.php b/lib/Sabberworm/CSS/RuleSet/RuleSet.php
index 124be88d..42b66509 100644
--- a/lib/Sabberworm/CSS/RuleSet/RuleSet.php
+++ b/lib/Sabberworm/CSS/RuleSet/RuleSet.php
@@ -2,9 +2,11 @@
 
 namespace Sabberworm\CSS\RuleSet;
 
-use Sabberworm\CSS\Rule\Rule;
-use Sabberworm\CSS\Renderable;
 use Sabberworm\CSS\Comment\Commentable;
+use Sabberworm\CSS\Parsing\ParserState;
+use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+use Sabberworm\CSS\Renderable;
+use Sabberworm\CSS\Rule\Rule;
 
 /**
  * RuleSet is a generic superclass denoting rules. The typical example for rule sets are declaration block.
@@ -22,6 +24,41 @@ public function __construct($iLineNo = 0) {
 		$this->aComments = array();
 	}
 
+	public static function parseRuleSet(ParserState $oParserState, RuleSet $oRuleSet) {
+		while ($oParserState->comes(';')) {
+			$oParserState->consume(';');
+		}
+		while (!$oParserState->comes('}')) {
+			$oRule = null;
+			if($oParserState->getSettings()->bLenientParsing) {
+				try {
+					$oRule = Rule::parse($oParserState);
+				} catch (UnexpectedTokenException $e) {
+					try {
+						$sConsume = $oParserState->consumeUntil(array("\n", ";", '}'), true);
+						// We need to “unfind” the matches to the end of the ruleSet as this will be matched later
+						if($oParserState->streql(substr($sConsume, -1), '}')) {
+							$oParserState->backtrack(1);
+						} else {
+							while ($oParserState->comes(';')) {
+								$oParserState->consume(';');
+							}
+						}
+					} catch (UnexpectedTokenException $e) {
+						// We’ve reached the end of the document. Just close the RuleSet.
+						return;
+					}
+				}
+			} else {
+				$oRule = Rule::parse($oParserState);
+			}
+			if($oRule) {
+				$oRuleSet->addRule($oRule);
+			}
+		}
+		$oParserState->consume('}');
+	}
+
 	/**
 	 * @return int
 	 */
diff --git a/lib/Sabberworm/CSS/Value/CSSString.php b/lib/Sabberworm/CSS/Value/CSSString.php
index b0700081..9f9c050e 100644
--- a/lib/Sabberworm/CSS/Value/CSSString.php
+++ b/lib/Sabberworm/CSS/Value/CSSString.php
@@ -2,6 +2,9 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\Parsing\ParserState;
+use Sabberworm\CSS\Parsing\SourceException;
+
 class CSSString extends PrimitiveValue {
 
 	private $sString;
@@ -11,6 +14,37 @@ public function __construct($sString, $iLineNo = 0) {
 		parent::__construct($iLineNo);
 	}
 
+	public static function parse(ParserState $oParserState) {
+		$sBegin = $oParserState->peek();
+		$sQuote = null;
+		if ($sBegin === "'") {
+			$sQuote = "'";
+		} else if ($sBegin === '"') {
+			$sQuote = '"';
+		}
+		if ($sQuote !== null) {
+			$oParserState->consume($sQuote);
+		}
+		$sResult = "";
+		$sContent = null;
+		if ($sQuote === null) {
+			// Unquoted strings end in whitespace or with braces, brackets, parentheses
+			while (!preg_match('/[\\s{}()<>\\[\\]]/isu', $oParserState->peek())) {
+				$sResult .= $oParserState->parseCharacter(false);
+			}
+		} else {
+			while (!$oParserState->comes($sQuote)) {
+				$sContent = $oParserState->parseCharacter(false);
+				if ($sContent === null) {
+					throw new SourceException("Non-well-formed quoted string {$oParserState->peek(3)}", $oParserState->currentLine());
+				}
+				$sResult .= $sContent;
+			}
+			$oParserState->consume($sQuote);
+		}
+		return new CSSString($sResult, $oParserState->currentLine());
+	}
+
 	public function setString($sString) {
 		$this->sString = $sString;
 	}
diff --git a/lib/Sabberworm/CSS/Value/CalcFunction.php b/lib/Sabberworm/CSS/Value/CalcFunction.php
index 0dba1b85..92475209 100644
--- a/lib/Sabberworm/CSS/Value/CalcFunction.php
+++ b/lib/Sabberworm/CSS/Value/CalcFunction.php
@@ -2,7 +2,61 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\Parsing\ParserState;
+use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+
 class CalcFunction extends CSSFunction {
 	const T_OPERAND  = 1;
 	const T_OPERATOR = 2;
+
+	public static function parse(ParserState $oParserState) {
+		$aOperators = array('+', '-', '*', '/');
+		$sFunction = trim($oParserState->consumeUntil('(', false, true));
+		$oCalcList = new CalcRuleValueList($oParserState->currentLine());
+		$oList = new RuleValueList(',', $oParserState->currentLine());
+		$iNestingLevel = 0;
+		$iLastComponentType = NULL;
+		while(!$oParserState->comes(')') || $iNestingLevel > 0) {
+			$oParserState->consumeWhiteSpace();
+			if ($oParserState->comes('(')) {
+				$iNestingLevel++;
+				$oCalcList->addListComponent($oParserState->consume(1));
+				continue;
+			} else if ($oParserState->comes(')')) {
+				$iNestingLevel--;
+				$oCalcList->addListComponent($oParserState->consume(1));
+				continue;
+			}
+			if ($iLastComponentType != CalcFunction::T_OPERAND) {
+				$oVal = Value::parsePrimitiveValue($oParserState);
+				$oCalcList->addListComponent($oVal);
+				$iLastComponentType = CalcFunction::T_OPERAND;
+			} else {
+				if (in_array($oParserState->peek(), $aOperators)) {
+					if (($oParserState->comes('-') || $oParserState->comes('+'))) {
+						if ($oParserState->peek(1, -1) != ' ' || !($oParserState->comes('- ') || $oParserState->comes('+ '))) {
+							throw new UnexpectedTokenException(" {$oParserState->peek()} ", $oParserState->peek(1, -1) . $oParserState->peek(2), 'literal', $oParserState->currentLine());
+						}
+					}
+					$oCalcList->addListComponent($oParserState->consume(1));
+					$iLastComponentType = CalcFunction::T_OPERATOR;
+				} else {
+					throw new UnexpectedTokenException(
+						sprintf(
+							'Next token was expected to be an operand of type %s. Instead "%s" was found.',
+							implode(', ', $aOperators),
+							$oVal
+						),
+						'',
+						'custom',
+						$oParserState->currentLine()
+					);
+				}
+			}
+		}
+		$oList->addListComponent($oCalcList);
+		$oParserState->consume(')');
+		return new CalcFunction($sFunction, $oList, ',', $oParserState->currentLine());
+	}
+
 }
diff --git a/lib/Sabberworm/CSS/Value/Color.php b/lib/Sabberworm/CSS/Value/Color.php
index e05b924a..c6ed9b18 100644
--- a/lib/Sabberworm/CSS/Value/Color.php
+++ b/lib/Sabberworm/CSS/Value/Color.php
@@ -2,12 +2,66 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\Parsing\ParserState;
+
 class Color extends CSSFunction {
 
 	public function __construct($aColor, $iLineNo = 0) {
 		parent::__construct(implode('', array_keys($aColor)), $aColor, ',', $iLineNo);
 	}
 
+	public static function parse(ParserState $oParserState) {
+		$aColor = array();
+		if ($oParserState->comes('#')) {
+			$oParserState->consume('#');
+			$sValue = $oParserState->parseIdentifier(false);
+			if ($oParserState->strlen($sValue) === 3) {
+				$sValue = $sValue[0] . $sValue[0] . $sValue[1] . $sValue[1] . $sValue[2] . $sValue[2];
+			} else if ($oParserState->strlen($sValue) === 4) {
+				$sValue = $sValue[0] . $sValue[0] . $sValue[1] . $sValue[1] . $sValue[2] . $sValue[2] . $sValue[3] . $sValue[3];
+			}
+
+			if ($oParserState->strlen($sValue) === 8) {
+				$aColor = array(
+					'r' => new Size(intval($sValue[0] . $sValue[1], 16), null, true, $oParserState->currentLine()),
+					'g' => new Size(intval($sValue[2] . $sValue[3], 16), null, true, $oParserState->currentLine()),
+					'b' => new Size(intval($sValue[4] . $sValue[5], 16), null, true, $oParserState->currentLine()),
+					'a' => new Size(round(self::mapRange(intval($sValue[6] . $sValue[7], 16), 0, 255, 0, 1), 2), null, true, $oParserState->currentLine())
+				);
+			} else {
+				$aColor = array(
+					'r' => new Size(intval($sValue[0] . $sValue[1], 16), null, true, $oParserState->currentLine()),
+					'g' => new Size(intval($sValue[2] . $sValue[3], 16), null, true, $oParserState->currentLine()),
+					'b' => new Size(intval($sValue[4] . $sValue[5], 16), null, true, $oParserState->currentLine())
+				);
+			}
+		} else {
+			$sColorMode = $oParserState->parseIdentifier(true);
+			$oParserState->consumeWhiteSpace();
+			$oParserState->consume('(');
+			$iLength = $oParserState->strlen($sColorMode);
+			for ($i = 0; $i < $iLength; ++$i) {
+				$oParserState->consumeWhiteSpace();
+				$aColor[$sColorMode[$i]] = Size::parse($oParserState, true);
+				$oParserState->consumeWhiteSpace();
+				if ($i < ($iLength - 1)) {
+					$oParserState->consume(',');
+				}
+			}
+			$oParserState->consume(')');
+		}
+		return new Color($aColor, $oParserState->currentLine());
+	}
+
+	private static function mapRange($fVal, $fFromMin, $fFromMax, $fToMin, $fToMax) {
+		$fFromRange = $fFromMax - $fFromMin;
+		$fToRange = $fToMax - $fToMin;
+		$fMultiplier = $fToRange / $fFromRange;
+		$fNewVal = $fVal - $fFromMin;
+		$fNewVal *= $fMultiplier;
+		return $fNewVal + $fToMin;
+	}
+
 	public function getColor() {
 		return $this->aComponents;
 	}
diff --git a/lib/Sabberworm/CSS/Value/LineName.php b/lib/Sabberworm/CSS/Value/LineName.php
index bc1fb85b..eb7392d7 100644
--- a/lib/Sabberworm/CSS/Value/LineName.php
+++ b/lib/Sabberworm/CSS/Value/LineName.php
@@ -2,11 +2,34 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\Parsing\ParserState;
+use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+
 class LineName extends ValueList {
 	public function __construct($aComponents = array(), $iLineNo = 0) {
 		parent::__construct($aComponents, ' ', $iLineNo);
 	}
 
+	public static function parse(ParserState $oParserState) {
+		$oParserState->consume('[');
+		$oParserState->consumeWhiteSpace();
+		$aNames = array();
+		do {
+			if($oParserState->getSettings()->bLenientParsing) {
+				try {
+					$aNames[] = $oParserState->parseIdentifier();
+				} catch(UnexpectedTokenException $e) {}
+			} else {
+				$aNames[] = $oParserState->parseIdentifier();
+			}
+			$oParserState->consumeWhiteSpace();
+		} while (!$oParserState->comes(']'));
+		$oParserState->consume(']');
+		return new LineName($aNames, $oParserState->currentLine());
+	}
+
+
+
 	public function __toString() {
 		return $this->render(new \Sabberworm\CSS\OutputFormat());
 	}
diff --git a/lib/Sabberworm/CSS/Value/Size.php b/lib/Sabberworm/CSS/Value/Size.php
index 9ad5eb08..9728a7b9 100644
--- a/lib/Sabberworm/CSS/Value/Size.php
+++ b/lib/Sabberworm/CSS/Value/Size.php
@@ -2,12 +2,16 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\Parsing\ParserState;
+
 class Size extends PrimitiveValue {
 
 	const ABSOLUTE_SIZE_UNITS = 'px/cm/mm/mozmm/in/pt/pc/vh/vw/vm/vmin/vmax/rem'; //vh/vw/vm(ax)/vmin/rem are absolute insofar as they don’t scale to the immediate parent (only the viewport)
 	const RELATIVE_SIZE_UNITS = '%/em/ex/ch/fr';
 	const NON_SIZE_UNITS = 'deg/grad/rad/s/ms/turns/Hz/kHz';
 
+	private static $SIZE_UNITS = null;
+
 	private $fSize;
 	private $sUnit;
 	private $bIsColorComponent;
@@ -19,6 +23,50 @@ public function __construct($fSize, $sUnit = null, $bIsColorComponent = false, $
 		$this->bIsColorComponent = $bIsColorComponent;
 	}
 
+	public static function parse(ParserState $oParserState, $bIsColorComponent = false) {
+		$sSize = '';
+		if ($oParserState->comes('-')) {
+			$sSize .= $oParserState->consume('-');
+		}
+		while (is_numeric($oParserState->peek()) || $oParserState->comes('.')) {
+			if ($oParserState->comes('.')) {
+				$sSize .= $oParserState->consume('.');
+			} else {
+				$sSize .= $oParserState->consume(1);
+			}
+		}
+
+		$sUnit = null;
+		foreach (self::getSizeUnits() as $iLength => &$aValues) {
+			$sKey = strtolower($oParserState->peek($iLength));
+			if(array_key_exists($sKey, $aValues)) {
+				if (($sUnit = $aValues[$sKey]) !== null) {
+					$oParserState->consume($iLength);
+					break;
+				}
+			}
+		}
+		return new Size(floatval($sSize), $sUnit, $bIsColorComponent, $oParserState->currentLine());
+	}
+
+	private static function getSizeUnits() {
+		if(self::$SIZE_UNITS === null) {
+			self::$SIZE_UNITS = [];
+			foreach (explode('/', Size::ABSOLUTE_SIZE_UNITS.'/'.Size::RELATIVE_SIZE_UNITS.'/'.Size::NON_SIZE_UNITS) as $val) {
+				$iSize = strlen($val);
+				if(!isset(self::$SIZE_UNITS[$iSize])) {
+					self::$SIZE_UNITS[$iSize] = array();
+				}
+				self::$SIZE_UNITS[$iSize][strtolower($val)] = $val;
+			}
+
+			// FIXME: Should we not order the longest units first?
+			ksort(self::$SIZE_UNITS, SORT_NUMERIC);
+		}
+
+		return self::$SIZE_UNITS;
+	}
+
 	public function setUnit($sUnit) {
 		$this->sUnit = $sUnit;
 	}
diff --git a/lib/Sabberworm/CSS/Value/URL.php b/lib/Sabberworm/CSS/Value/URL.php
index 02cf5812..b4f37e16 100644
--- a/lib/Sabberworm/CSS/Value/URL.php
+++ b/lib/Sabberworm/CSS/Value/URL.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\Parsing\ParserState;
 
 class URL extends PrimitiveValue {
 
@@ -12,6 +13,23 @@ public function __construct(CSSString $oURL, $iLineNo = 0) {
 		$this->oURL = $oURL;
 	}
 
+	public static function parse(ParserState $oParserState) {
+		$bUseUrl = $oParserState->comes('url', true);
+		if ($bUseUrl) {
+			$oParserState->consume('url');
+			$oParserState->consumeWhiteSpace();
+			$oParserState->consume('(');
+		}
+		$oParserState->consumeWhiteSpace();
+		$oResult = new URL(CSSString::parse($oParserState), $oParserState->currentLine());
+		if ($bUseUrl) {
+			$oParserState->consumeWhiteSpace();
+			$oParserState->consume(')');
+		}
+		return $oResult;
+	}
+
+
 	public function setURL(CSSString $oURL) {
 		$this->oURL = $oURL;
 	}
diff --git a/lib/Sabberworm/CSS/Value/Value.php b/lib/Sabberworm/CSS/Value/Value.php
index 5d30bd97..5c550498 100644
--- a/lib/Sabberworm/CSS/Value/Value.php
+++ b/lib/Sabberworm/CSS/Value/Value.php
@@ -2,23 +2,113 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Renderable;
 
 abstract class Value implements Renderable {
-    protected $iLineNo;
-
-    public function __construct($iLineNo = 0) {
-        $this->iLineNo = $iLineNo;
-    }
-    
-    /**
-     * @return int
-     */
-    public function getLineNo() {
-        return $this->iLineNo;
-    }
-
-    //Methods are commented out because re-declaring them here is a fatal error in PHP < 5.3.9
+	protected $iLineNo;
+
+	public function __construct($iLineNo = 0) {
+		$this->iLineNo = $iLineNo;
+	}
+
+	public static function parseValue(ParserState $oParserState, $aListDelimiters = array()) {
+		$aStack = array();
+		$oParserState->consumeWhiteSpace();
+		//Build a list of delimiters and parsed values
+		while (!($oParserState->comes('}') || $oParserState->comes(';') || $oParserState->comes('!') || $oParserState->comes(')') || $oParserState->comes('\\'))) {
+			if (count($aStack) > 0) {
+				$bFoundDelimiter = false;
+				foreach ($aListDelimiters as $sDelimiter) {
+					if ($oParserState->comes($sDelimiter)) {
+						array_push($aStack, $oParserState->consume($sDelimiter));
+						$oParserState->consumeWhiteSpace();
+						$bFoundDelimiter = true;
+						break;
+					}
+				}
+				if (!$bFoundDelimiter) {
+					//Whitespace was the list delimiter
+					array_push($aStack, ' ');
+				}
+			}
+			array_push($aStack, self::parsePrimitiveValue($oParserState));
+			$oParserState->consumeWhiteSpace();
+		}
+		//Convert the list to list objects
+		foreach ($aListDelimiters as $sDelimiter) {
+			if (count($aStack) === 1) {
+				return $aStack[0];
+			}
+			$iStartPosition = null;
+			while (($iStartPosition = array_search($sDelimiter, $aStack, true)) !== false) {
+				$iLength = 2; //Number of elements to be joined
+				for ($i = $iStartPosition + 2; $i < count($aStack); $i+=2, ++$iLength) {
+					if ($sDelimiter !== $aStack[$i]) {
+						break;
+					}
+				}
+				$oList = new RuleValueList($sDelimiter, $oParserState->currentLine());
+				for ($i = $iStartPosition - 1; $i - $iStartPosition + 1 < $iLength * 2; $i+=2) {
+					$oList->addListComponent($aStack[$i]);
+				}
+				array_splice($aStack, $iStartPosition - 1, $iLength * 2 - 1, array($oList));
+			}
+		}
+		return $aStack[0];
+	}
+
+	public static function parseIdentifierOrFunction(ParserState $oParserState, $bIgnoreCase = false) {
+		$sResult = $oParserState->parseIdentifier($bIgnoreCase);
+
+		if ($oParserState->comes('(')) {
+			$oParserState->consume('(');
+			$aArguments = Value::parseValue($oParserState, array('=', ' ', ','));
+			$sResult = new CSSFunction($sResult, $aArguments, ',', $oParserState->currentLine());
+			$oParserState->consume(')');
+		}
+
+		return $sResult;
+	}
+
+	public static function parsePrimitiveValue(ParserState $oParserState) {
+		$oValue = null;
+		$oParserState->consumeWhiteSpace();
+		if (is_numeric($oParserState->peek()) || ($oParserState->comes('-.') && is_numeric($oParserState->peek(1, 2))) || (($oParserState->comes('-') || $oParserState->comes('.')) && is_numeric($oParserState->peek(1, 1)))) {
+			$oValue = Size::parse($oParserState);
+		} else if ($oParserState->comes('#') || $oParserState->comes('rgb', true) || $oParserState->comes('hsl', true)) {
+			$oValue = Color::parse($oParserState);
+		} else if ($oParserState->comes('url', true)) {
+			$oValue = URL::parse($oParserState);
+		} else if ($oParserState->comes('calc', true) || $oParserState->comes('-webkit-calc', true) || $oParserState->comes('-moz-calc', true)) {
+			$oValue = CalcFunction::parse($oParserState);
+		} else if ($oParserState->comes("'") || $oParserState->comes('"')) {
+			$oValue = CSSString::parse($oParserState);
+		} else if ($oParserState->comes("progid:") && $oParserState->getSettings()->bLenientParsing) {
+			$oValue = self::parseMicrosoftFilter($oParserState);
+		} else if ($oParserState->comes("[")) {
+			$oValue = LineName::parse($oParserState);
+		} else {
+			$oValue = self::parseIdentifierOrFunction($oParserState);
+		}
+		$oParserState->consumeWhiteSpace();
+		return $oValue;
+	}
+
+	private static function parseMicrosoftFilter(ParserState $oParserState) {
+		$sFunction = $oParserState->consumeUntil('(', false, true);
+		$aArguments = Value::parseValue($oParserState, array(',', '='));
+		return new CSSFunction($sFunction, $aArguments, ',', $oParserState->currentLine());
+	}
+	
+	/**
+	 * @return int
+	 */
+	public function getLineNo() {
+		return $this->iLineNo;
+	}
+
+	//Methods are commented out because re-declaring them here is a fatal error in PHP < 5.3.9
 	//public abstract function __toString();
 	//public abstract function render(\Sabberworm\CSS\OutputFormat $oOutputFormat);
 }

From de71450bf6e8dd4612617a64d791bf8221d18079 Mon Sep 17 00:00:00 2001
From: Raphael Schweikert <any@sabberworm.com>
Date: Fri, 19 Oct 2018 09:28:40 +0200
Subject: [PATCH 03/13] Use bin path to phpunit

---
 .travis.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index b755ca20..4731e182 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,4 +16,4 @@ matrix:
             dist: precise
             sudo: false
 before_script: rm composer.lock && composer install
-script: ./vendor/phpunit/phpunit/phpunit
+script: ./vendor/bin/phpunit

From ff6fa22ccf49a0450a5c3258171377ab5991edd2 Mon Sep 17 00:00:00 2001
From: Raphael Schweikert <any@sabberworm.com>
Date: Fri, 19 Oct 2018 09:47:50 +0200
Subject: [PATCH 04/13] Restore PHP 5.3 and 5.4 compatibility

---
 lib/Sabberworm/CSS/Value/Size.php | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/Sabberworm/CSS/Value/Size.php b/lib/Sabberworm/CSS/Value/Size.php
index 9728a7b9..f65246b5 100644
--- a/lib/Sabberworm/CSS/Value/Size.php
+++ b/lib/Sabberworm/CSS/Value/Size.php
@@ -37,7 +37,8 @@ public static function parse(ParserState $oParserState, $bIsColorComponent = fal
 		}
 
 		$sUnit = null;
-		foreach (self::getSizeUnits() as $iLength => &$aValues) {
+		$aSizeUnits = self::getSizeUnits();
+		foreach($aSizeUnits as $iLength => &$aValues) {
 			$sKey = strtolower($oParserState->peek($iLength));
 			if(array_key_exists($sKey, $aValues)) {
 				if (($sUnit = $aValues[$sKey]) !== null) {
@@ -51,7 +52,7 @@ public static function parse(ParserState $oParserState, $bIsColorComponent = fal
 
 	private static function getSizeUnits() {
 		if(self::$SIZE_UNITS === null) {
-			self::$SIZE_UNITS = [];
+			self::$SIZE_UNITS = array();
 			foreach (explode('/', Size::ABSOLUTE_SIZE_UNITS.'/'.Size::RELATIVE_SIZE_UNITS.'/'.Size::NON_SIZE_UNITS) as $val) {
 				$iSize = strlen($val);
 				if(!isset(self::$SIZE_UNITS[$iSize])) {

From fa212042fd1a3e75e498e4c61822acddd9deb705 Mon Sep 17 00:00:00 2001
From: Raphael Schweikert <any@sabberworm.com>
Date: Mon, 22 Oct 2018 16:59:42 +0200
Subject: [PATCH 05/13] Add coverage reporting

---
 .travis.yml   |   4 +-
 composer.json |   3 +-
 composer.lock | 279 +++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 283 insertions(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 4731e182..58537f7c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,4 +16,6 @@ matrix:
             dist: precise
             sudo: false
 before_script: rm composer.lock && composer install
-script: ./vendor/bin/phpunit
+script: ./vendor/bin/phpunit --coverage-clover build/coverage/xml
+after_script: ./vendor/bin/codacycoverage clover build/coverage/xml
+
diff --git a/composer.json b/composer.json
index ace92099..5e73c8aa 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,8 @@
         "php": ">=5.3.2"
     },
     "require-dev": {
-        "phpunit/phpunit": "~4.8"
+        "phpunit/phpunit": "~4.8",
+        "codacy/coverage": "^1.4"
     },
     "autoload": {
         "psr-0": { "Sabberworm\\CSS": "lib/" }
diff --git a/composer.lock b/composer.lock
index 794ccf0d..c40bc3d3 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,9 +4,54 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "e18ad71715023d7c668850babb457c23",
+    "content-hash": "a09a0e09f5a1356a2c833ec123e09593",
     "packages": [],
     "packages-dev": [
+        {
+            "name": "codacy/coverage",
+            "version": "1.4.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/codacy/php-codacy-coverage.git",
+                "reference": "4988cd098db4d578681bfd3176071931ad475150"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/codacy/php-codacy-coverage/zipball/4988cd098db4d578681bfd3176071931ad475150",
+                "reference": "4988cd098db4d578681bfd3176071931ad475150",
+                "shasum": ""
+            },
+            "require": {
+                "gitonomy/gitlib": ">=1.0",
+                "php": ">=5.3.3",
+                "symfony/console": "~2.5|~3.0|~4.0"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "~6.5"
+            },
+            "bin": [
+                "bin/codacycoverage"
+            ],
+            "type": "library",
+            "autoload": {
+                "classmap": [
+                    "src/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Jakob Pupke",
+                    "email": "jakob.pupke@gmail.com"
+                }
+            ],
+            "description": "Sends PHP test coverage information to Codacy.",
+            "homepage": "https://github.com/codacy/php-codacy-coverage",
+            "time": "2018-03-22T16:43:39+00:00"
+        },
         {
             "name": "doctrine/instantiator",
             "version": "1.1.0",
@@ -61,6 +106,62 @@
             ],
             "time": "2017-07-22T11:58:36+00:00"
         },
+        {
+            "name": "gitonomy/gitlib",
+            "version": "v1.0.4",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/gitonomy/gitlib.git",
+                "reference": "932a960221ae3484a3e82553b3be478e56beb68d"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/gitonomy/gitlib/zipball/932a960221ae3484a3e82553b3be478e56beb68d",
+                "reference": "932a960221ae3484a3e82553b3be478e56beb68d",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^5.3 || ^7.0",
+                "symfony/process": "^2.3|^3.0|^4.0"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "^4.8.35|^5.7",
+                "psr/log": "^1.0"
+            },
+            "suggest": {
+                "psr/log": "Add some log"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.0-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Gitonomy\\Git\\": "src/Gitonomy/Git/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Alexandre Salomé",
+                    "email": "alexandre.salome@gmail.com",
+                    "homepage": "http://alexandre-salome.fr"
+                },
+                {
+                    "name": "Julien DIDIER",
+                    "email": "genzo.wm@gmail.com",
+                    "homepage": "http://www.jdidier.net"
+                }
+            ],
+            "description": "Library for accessing git",
+            "homepage": "http://gitonomy.com",
+            "time": "2018-04-22T19:55:36+00:00"
+        },
         {
             "name": "phpdocumentor/reflection-common",
             "version": "1.0.1",
@@ -1024,6 +1125,74 @@
             "homepage": "https://github.com/sebastianbergmann/version",
             "time": "2015-06-21T13:59:46+00:00"
         },
+        {
+            "name": "symfony/console",
+            "version": "v4.1.6",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/console.git",
+                "reference": "dc7122fe5f6113cfaba3b3de575d31112c9aa60b"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/console/zipball/dc7122fe5f6113cfaba3b3de575d31112c9aa60b",
+                "reference": "dc7122fe5f6113cfaba3b3de575d31112c9aa60b",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.1.3",
+                "symfony/polyfill-mbstring": "~1.0"
+            },
+            "conflict": {
+                "symfony/dependency-injection": "<3.4",
+                "symfony/process": "<3.3"
+            },
+            "require-dev": {
+                "psr/log": "~1.0",
+                "symfony/config": "~3.4|~4.0",
+                "symfony/dependency-injection": "~3.4|~4.0",
+                "symfony/event-dispatcher": "~3.4|~4.0",
+                "symfony/lock": "~3.4|~4.0",
+                "symfony/process": "~3.4|~4.0"
+            },
+            "suggest": {
+                "psr/log-implementation": "For using the console logger",
+                "symfony/event-dispatcher": "",
+                "symfony/lock": "",
+                "symfony/process": ""
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "4.1-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Component\\Console\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony Console Component",
+            "homepage": "https://symfony.com",
+            "time": "2018-10-03T08:15:46+00:00"
+        },
         {
             "name": "symfony/polyfill-ctype",
             "version": "v1.8.0",
@@ -1079,6 +1248,114 @@
             ],
             "time": "2018-04-30T19:57:29+00:00"
         },
+        {
+            "name": "symfony/polyfill-mbstring",
+            "version": "v1.9.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/polyfill-mbstring.git",
+                "reference": "d0cd638f4634c16d8df4508e847f14e9e43168b8"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/polyfill-mbstring/zipball/d0cd638f4634c16d8df4508e847f14e9e43168b8",
+                "reference": "d0cd638f4634c16d8df4508e847f14e9e43168b8",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.3"
+            },
+            "suggest": {
+                "ext-mbstring": "For best performance"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.9-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Polyfill\\Mbstring\\": ""
+                },
+                "files": [
+                    "bootstrap.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Nicolas Grekas",
+                    "email": "p@tchwork.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony polyfill for the Mbstring extension",
+            "homepage": "https://symfony.com",
+            "keywords": [
+                "compatibility",
+                "mbstring",
+                "polyfill",
+                "portable",
+                "shim"
+            ],
+            "time": "2018-08-06T14:22:27+00:00"
+        },
+        {
+            "name": "symfony/process",
+            "version": "v4.1.6",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/process.git",
+                "reference": "ee33c0322a8fee0855afcc11fff81e6b1011b529"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/process/zipball/ee33c0322a8fee0855afcc11fff81e6b1011b529",
+                "reference": "ee33c0322a8fee0855afcc11fff81e6b1011b529",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.1.3"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "4.1-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Component\\Process\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony Process Component",
+            "homepage": "https://symfony.com",
+            "time": "2018-10-02T12:40:59+00:00"
+        },
         {
             "name": "symfony/yaml",
             "version": "v3.4.12",

From a7a80b4e28c8feebeff95413e2b41ef8487cfb65 Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Mon, 14 Jan 2019 13:47:27 -0800
Subject: [PATCH 06/13] Add splice method to CSSList

---
 lib/Sabberworm/CSS/CSSList/CSSList.php | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/lib/Sabberworm/CSS/CSSList/CSSList.php b/lib/Sabberworm/CSS/CSSList/CSSList.php
index c4b28065..3736d8f3 100644
--- a/lib/Sabberworm/CSS/CSSList/CSSList.php
+++ b/lib/Sabberworm/CSS/CSSList/CSSList.php
@@ -176,17 +176,39 @@ public function getLineNo() {
 		return $this->iLineNo;
 	}
 
+	/**
+	 * Prepend item to list of contents.
+	 *
+	 * @param object $oItem Item.
+	 */
 	public function prepend($oItem) {
 		array_unshift($this->aContents, $oItem);
 	}
 
+	/**
+	 * Append item to list of contents.
+	 *
+	 * @param object $oItem Item.
+	 */
 	public function append($oItem) {
 		$this->aContents[] = $oItem;
 	}
 
+	/**
+	 * Splice the list of contents.
+	 *
+	 * @param int       $iOffset      Offset.
+	 * @param int       $iLength      Length. Optional.
+	 * @param RuleSet[] $mReplacement Replacement. Optional.
+	 */
+	public function splice($iOffset, $iLength = null, $mReplacement = null) {
+		array_splice($this->aContents, $iOffset, $iLength, $mReplacement);
+	}
+
 	/**
 	 * Removes an item from the CSS list.
 	 * @param RuleSet|Import|Charset|CSSList $oItemToRemove May be a RuleSet (most likely a DeclarationBlock), a Import, a Charset or another CSSList (most likely a MediaQuery)
+	 * @return bool Whether the item was removed.
 	 */
 	public function remove($oItemToRemove) {
 		$iKey = array_search($oItemToRemove, $this->aContents, true);

From 032b86cc5f1b43969ea55a0ff6405cf7c8c67f26 Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Tue, 15 Jan 2019 14:12:28 -0800
Subject: [PATCH 07/13] Extend output formatting with additional delimiter
 options

Allow content to be added before/after at-rule blocks.
Also allow content to be added before a declaration block, after its selectors, and then after the declaration block.
---
 lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php  |  4 +++-
 lib/Sabberworm/CSS/OutputFormat.php             | 11 ++++++++++-
 lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php |  6 +++++-
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php b/lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php
index a1ff8f8d..24e79f02 100644
--- a/lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php
+++ b/lib/Sabberworm/CSS/CSSList/AtRuleBlockList.php
@@ -35,9 +35,11 @@ public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		if($sArgs) {
 			$sArgs = ' ' . $sArgs;
 		}
-		$sResult = "@{$this->sType}$sArgs{$oOutputFormat->spaceBeforeOpeningBrace()}{";
+		$sResult  = $oOutputFormat->sBeforeAtRuleBlock;
+		$sResult .= "@{$this->sType}$sArgs{$oOutputFormat->spaceBeforeOpeningBrace()}{";
 		$sResult .= parent::render($oOutputFormat);
 		$sResult .= '}';
+		$sResult .= $oOutputFormat->sAfterAtRuleBlock;
 		return $sResult;
 	}
 
diff --git a/lib/Sabberworm/CSS/OutputFormat.php b/lib/Sabberworm/CSS/OutputFormat.php
index 45b97f52..7279bfb7 100644
--- a/lib/Sabberworm/CSS/OutputFormat.php
+++ b/lib/Sabberworm/CSS/OutputFormat.php
@@ -35,6 +35,10 @@ class OutputFormat {
 	public $sSpaceAfterBlocks = '';
 	public $sSpaceBetweenBlocks = "\n";
 
+	// Content injected in and around @-rule blocks.
+	public $sBeforeAtRuleBlock = '';
+	public $sAfterAtRuleBlock = '';
+
 	// This is what’s printed before and after the comma if a declaration block contains multiple selectors.
 	public $sSpaceBeforeSelectorSeparator = '';
 	public $sSpaceAfterSelectorSeparator = ' ';
@@ -43,7 +47,12 @@ class OutputFormat {
 	public $sSpaceAfterListArgumentSeparator = '';
 	
 	public $sSpaceBeforeOpeningBrace = ' ';
-	
+
+	// Content injected in and around declaration blocks.
+	public $sBeforeDeclarationBlock = '';
+	public $sAfterDeclarationBlockSelectors = '';
+	public $sAfterDeclarationBlock = '';
+
 	/**
 	* Indentation
 	*/
diff --git a/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php b/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
index 451eaa7e..726d2154 100644
--- a/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
+++ b/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
@@ -610,9 +610,13 @@ public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 			// If all the selectors have been removed, this declaration block becomes invalid
 			throw new OutputException("Attempt to print declaration block with missing selector", $this->iLineNo);
 		}
-		$sResult = $oOutputFormat->implode($oOutputFormat->spaceBeforeSelectorSeparator() . ',' . $oOutputFormat->spaceAfterSelectorSeparator(), $this->aSelectors) . $oOutputFormat->spaceBeforeOpeningBrace() . '{';
+		$sResult = $oOutputFormat->sBeforeDeclarationBlock;
+		$sResult .= $oOutputFormat->implode($oOutputFormat->spaceBeforeSelectorSeparator() . ',' . $oOutputFormat->spaceAfterSelectorSeparator(), $this->aSelectors);
+		$sResult .= $oOutputFormat->sAfterDeclarationBlockSelectors;
+		$sResult .= $oOutputFormat->spaceBeforeOpeningBrace() . '{';
 		$sResult .= parent::render($oOutputFormat);
 		$sResult .= '}';
+		$sResult .= $oOutputFormat->sAfterDeclarationBlock;
 		return $sResult;
 	}
 

From 048af5b61b0ebd8a1eb910b3ae4e3a744c7038fa Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Tue, 15 Jan 2019 14:13:10 -0800
Subject: [PATCH 08/13] Improve phpdoc for methods

---
 lib/Sabberworm/CSS/OutputFormat.php | 34 ++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/lib/Sabberworm/CSS/OutputFormat.php b/lib/Sabberworm/CSS/OutputFormat.php
index 7279bfb7..f7ebb5a5 100644
--- a/lib/Sabberworm/CSS/OutputFormat.php
+++ b/lib/Sabberworm/CSS/OutputFormat.php
@@ -4,6 +4,11 @@
 
 use Sabberworm\CSS\Parsing\OutputException;
 
+/**
+ * Class OutputFormat
+ *
+ * @method OutputFormat setSemicolonAfterLastRule( bool $bSemicolonAfterLastRule ) Set whether semicolons are added after last rule.
+ */
 class OutputFormat {
 	/**
 	* Value format
@@ -150,17 +155,36 @@ public function getFormatter() {
 	public function level() {
 		return $this->iIndentationLevel;
 	}
-	
+
+	/**
+	 * Create format.
+	 *
+	 * @return OutputFormat Format.
+	 */
 	public static function create() {
 		return new OutputFormat();
 	}
-	
+
+	/**
+	 * Create compact format.
+	 *
+	 * @return OutputFormat Format.
+	 */
 	public static function createCompact() {
-		return self::create()->set('Space*Rules', "")->set('Space*Blocks', "")->setSpaceAfterRuleName('')->setSpaceBeforeOpeningBrace('')->setSpaceAfterSelectorSeparator('');
+		$format = self::create();
+		$format->set('Space*Rules', "")->set('Space*Blocks', "")->setSpaceAfterRuleName('')->setSpaceBeforeOpeningBrace('')->setSpaceAfterSelectorSeparator('');
+		return $format;
 	}
-	
+
+	/**
+	 * Create pretty format.
+	 *
+	 * @return OutputFormat Format.
+	 */
 	public static function createPretty() {
-		return self::create()->set('Space*Rules', "\n")->set('Space*Blocks', "\n")->setSpaceBetweenBlocks("\n\n")->set('SpaceAfterListArgumentSeparator', array('default' => '', ',' => ' '));
+		$format = self::create();
+		$format->set('Space*Rules', "\n")->set('Space*Blocks', "\n")->setSpaceBetweenBlocks("\n\n")->set('SpaceAfterListArgumentSeparator', array('default' => '', ',' => ' '));
+		return $format;
 	}
 }
 

From c0800de1abb4229b444a1da287fa5a02adbb3183 Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Tue, 15 Jan 2019 15:46:10 -0800
Subject: [PATCH 09/13] Add phpdoc return tags

---
 lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php | 5 +++++
 lib/Sabberworm/CSS/RuleSet/RuleSet.php          | 8 +++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php b/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
index 726d2154..6614b1d1 100644
--- a/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
+++ b/lib/Sabberworm/CSS/RuleSet/DeclarationBlock.php
@@ -76,6 +76,11 @@ public function setSelector($mSelector) {
 		$this->setSelectors($mSelector);
 	}
 
+	/**
+	 * Get selectors.
+	 *
+	 * @return Selector[] Selectors.
+	 */
 	public function getSelectors() {
 		return $this->aSelectors;
 	}
diff --git a/lib/Sabberworm/CSS/RuleSet/RuleSet.php b/lib/Sabberworm/CSS/RuleSet/RuleSet.php
index 42b66509..0f44b091 100644
--- a/lib/Sabberworm/CSS/RuleSet/RuleSet.php
+++ b/lib/Sabberworm/CSS/RuleSet/RuleSet.php
@@ -89,6 +89,7 @@ public function addRule(Rule $oRule, Rule $oSibling = null) {
 	 * @param (null|string|Rule) $mRule pattern to search for. If null, returns all rules. if the pattern ends with a dash, all rules starting with the pattern are returned as well as one matching the pattern with the dash excluded. passing a Rule behaves like calling getRules($mRule->getRule()).
 	 * @example $oRuleSet->getRules('font-') //returns an array of all rules either beginning with font- or matching font.
 	 * @example $oRuleSet->getRules('font') //returns array(0 => $oRule, …) or array().
+	 * @return Rule[] Rules.
 	 */
 	public function getRules($mRule = null) {
 		if ($mRule instanceof Rule) {
@@ -119,6 +120,7 @@ public function setRules(array $aRules) {
 	 * Returns all rules matching the given pattern and returns them in an associative array with the rule’s name as keys. This method exists mainly for backwards-compatibility and is really only partially useful.
 	 * @param (string) $mRule pattern to search for. If null, returns all rules. if the pattern ends with a dash, all rules starting with the pattern are returned as well as one matching the pattern with the dash excluded. passing a Rule behaves like calling getRules($mRule->getRule()).
 	 * Note: This method loses some information: Calling this (with an argument of 'background-') on a declaration block like { background-color: green; background-color; rgba(0, 127, 0, 0.7); } will only yield an associative array containing the rgba-valued rule while @link{getRules()} would yield an indexed array containing both.
+	 * @return array Rules.
 	 */
 	public function getRulesAssoc($mRule = null) {
 		$aResult = array();
@@ -129,9 +131,9 @@ public function getRulesAssoc($mRule = null) {
 	}
 
 	/**
-	* Remove a rule from this RuleSet. This accepts all the possible values that @link{getRules()} accepts. If given a Rule, it will only remove this particular rule (by identity). If given a name, it will remove all rules by that name. Note: this is different from pre-v.2.0 behaviour of PHP-CSS-Parser, where passing a Rule instance would remove all rules with the same name. To get the old behvaiour, use removeRule($oRule->getRule()).
- * @param (null|string|Rule) $mRule pattern to remove. If $mRule is null, all rules are removed. If the pattern ends in a dash, all rules starting with the pattern are removed as well as one matching the pattern with the dash excluded. Passing a Rule behaves matches by identity.
-	*/
+	 * Remove a rule from this RuleSet. This accepts all the possible values that @link{getRules()} accepts. If given a Rule, it will only remove this particular rule (by identity). If given a name, it will remove all rules by that name. Note: this is different from pre-v.2.0 behaviour of PHP-CSS-Parser, where passing a Rule instance would remove all rules with the same name. To get the old behvaiour, use removeRule($oRule->getRule()).
+	 * @param (null|string|Rule) $mRule pattern to remove. If $mRule is null, all rules are removed. If the pattern ends in a dash, all rules starting with the pattern are removed as well as one matching the pattern with the dash excluded. Passing a Rule behaves matches by identity.
+	 */
 	public function removeRule($mRule) {
 		if($mRule instanceof Rule) {
 			$sRule = $mRule->getRule();

From 28e4274cb108bedcdb0e8398a89122a63aafbb29 Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Tue, 15 Jan 2019 15:47:49 -0800
Subject: [PATCH 10/13] Use Rule[] instead of generic array for return tags

---
 lib/Sabberworm/CSS/RuleSet/RuleSet.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/Sabberworm/CSS/RuleSet/RuleSet.php b/lib/Sabberworm/CSS/RuleSet/RuleSet.php
index 0f44b091..e5d5e415 100644
--- a/lib/Sabberworm/CSS/RuleSet/RuleSet.php
+++ b/lib/Sabberworm/CSS/RuleSet/RuleSet.php
@@ -107,7 +107,7 @@ public function getRules($mRule = null) {
 
 	/**
 	 * Override all the rules of this set.
-	 * @param array $aRules The rules to override with.
+	 * @param Rule[] $aRules The rules to override with.
 	 */
 	public function setRules(array $aRules) {
 		$this->aRules = array();
@@ -120,7 +120,7 @@ public function setRules(array $aRules) {
 	 * Returns all rules matching the given pattern and returns them in an associative array with the rule’s name as keys. This method exists mainly for backwards-compatibility and is really only partially useful.
 	 * @param (string) $mRule pattern to search for. If null, returns all rules. if the pattern ends with a dash, all rules starting with the pattern are returned as well as one matching the pattern with the dash excluded. passing a Rule behaves like calling getRules($mRule->getRule()).
 	 * Note: This method loses some information: Calling this (with an argument of 'background-') on a declaration block like { background-color: green; background-color; rgba(0, 127, 0, 0.7); } will only yield an associative array containing the rgba-valued rule while @link{getRules()} would yield an indexed array containing both.
-	 * @return array Rules.
+	 * @return Rule[] Rules.
 	 */
 	public function getRulesAssoc($mRule = null) {
 		$aResult = array();

From d2bb89bd441e8a90532675ab12b1c4fa0493cabf Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Thu, 17 Jan 2019 22:16:43 -0800
Subject: [PATCH 11/13] Fix undefined index notice when property lacks value

---
 lib/Sabberworm/CSS/Value/Value.php | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/Sabberworm/CSS/Value/Value.php b/lib/Sabberworm/CSS/Value/Value.php
index 5c550498..98b43d02 100644
--- a/lib/Sabberworm/CSS/Value/Value.php
+++ b/lib/Sabberworm/CSS/Value/Value.php
@@ -55,6 +55,9 @@ public static function parseValue(ParserState $oParserState, $aListDelimiters =
 				array_splice($aStack, $iStartPosition - 1, $iLength * 2 - 1, array($oList));
 			}
 		}
+		if (!isset($aStack[0])) {
+			return null;
+		}
 		return $aStack[0];
 	}
 

From 2c61b738f9972ad5d58d3755296abf2f214b02da Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Tue, 29 Jan 2019 10:24:51 -0800
Subject: [PATCH 12/13] Throw UnexpectedTokenException when no property value
 present

---
 lib/Sabberworm/CSS/Value/Value.php  |  3 +-
 tests/Sabberworm/CSS/ParserTest.php | 49 +++++++++++++++++++++++++----
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/lib/Sabberworm/CSS/Value/Value.php b/lib/Sabberworm/CSS/Value/Value.php
index 98b43d02..ae361dd7 100644
--- a/lib/Sabberworm/CSS/Value/Value.php
+++ b/lib/Sabberworm/CSS/Value/Value.php
@@ -3,6 +3,7 @@
 namespace Sabberworm\CSS\Value;
 
 use Sabberworm\CSS\Parsing\ParserState;
+use Sabberworm\CSS\Parsing\UnexpectedTokenException;
 use Sabberworm\CSS\Renderable;
 
 abstract class Value implements Renderable {
@@ -56,7 +57,7 @@ public static function parseValue(ParserState $oParserState, $aListDelimiters =
 			}
 		}
 		if (!isset($aStack[0])) {
-			return null;
+			throw new UnexpectedTokenException(" {$oParserState->peek()} ", $oParserState->peek(1, -1) . $oParserState->peek(2), 'literal', $oParserState->currentLine());
 		}
 		return $aStack[0];
 	}
diff --git a/tests/Sabberworm/CSS/ParserTest.php b/tests/Sabberworm/CSS/ParserTest.php
index ea8bbdf5..0922b11e 100644
--- a/tests/Sabberworm/CSS/ParserTest.php
+++ b/tests/Sabberworm/CSS/ParserTest.php
@@ -472,26 +472,63 @@ function testTrailingWhitespace() {
 	}
 
 	/**
-	* @expectedException Sabberworm\CSS\Parsing\UnexpectedTokenException
-	*/
+	 * @expectedException \Sabberworm\CSS\Parsing\UnexpectedTokenException
+	 */
 	function testCharsetFailure1() {
 		$this->parsedStructureForFile('-charset-after-rule', Settings::create()->withLenientParsing(false));
 	}
 
 	/**
-	* @expectedException Sabberworm\CSS\Parsing\UnexpectedTokenException
-	*/
+	 * @expectedException \Sabberworm\CSS\Parsing\UnexpectedTokenException
+	 */
 	function testCharsetFailure2() {
 		$this->parsedStructureForFile('-charset-in-block', Settings::create()->withLenientParsing(false));
 	}
 
 	/**
-	* @expectedException Sabberworm\CSS\Parsing\SourceException
-	*/
+	 * @expectedException \Sabberworm\CSS\Parsing\SourceException
+	 */
 	function testUnopenedClosingBracketFailure() {
 		$this->parsedStructureForFile('unopened-close-brackets', Settings::create()->withLenientParsing(false));
 	}
 
+	/**
+	 * Ensure that a missing property value raises an exception.
+	 *
+	 * @expectedException \Sabberworm\CSS\Parsing\UnexpectedTokenException
+	 * @covers \Sabberworm\CSS\Value\Value::parseValue()
+	 */
+	function testMissingPropertyValueStrict() {
+		$this->parsedStructureForFile('missing-property-value', Settings::create()->withLenientParsing(false));
+	}
+
+	/**
+	 * Ensure that a missing property value is ignored when in lenient parsing mode.
+	 *
+	 * @covers \Sabberworm\CSS\Value\Value::parseValue()
+	 */
+	function testMissingPropertyValueLenient() {
+		$parsed = $this->parsedStructureForFile('missing-property-value', Settings::create()->withLenientParsing(true));
+		$rulesets = $parsed->getAllRuleSets();
+		$this->assertCount( 1, $rulesets );
+		$block = $rulesets[0];
+		$this->assertTrue( $block instanceof DeclarationBlock );
+		$this->assertEquals( array( 'div' ), $block->getSelectors() );
+		$rules = $block->getRules();
+		$this->assertCount( 1, $rules );
+		$rule = $rules[0];
+		$this->assertEquals( 'display', $rule->getRule() );
+		$this->assertEquals( 'inline-block', $rule->getValue() );
+	}
+
+	/**
+	 * Parse structure for file.
+	 *
+	 * @param string      $sFileName Filename.
+	 * @param null|obJeCt $oSettings Settings.
+	 *
+	 * @return CSSList\Document Parsed document.
+	 */
 	function parsedStructureForFile($sFileName, $oSettings = null) {
 		$sFile = dirname(__FILE__) . '/../../files' . DIRECTORY_SEPARATOR . "$sFileName.css";
 		$oParser = new Parser(file_get_contents($sFile), $oSettings);

From cae9d7accabf1b145c6f9d67d51622b6829a99b4 Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Tue, 29 Jan 2019 10:26:52 -0800
Subject: [PATCH 13/13] Add missing missing-property-value.css file

---
 tests/files/missing-property-value.css | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 tests/files/missing-property-value.css

diff --git a/tests/files/missing-property-value.css b/tests/files/missing-property-value.css
new file mode 100644
index 00000000..33eb473d
--- /dev/null
+++ b/tests/files/missing-property-value.css
@@ -0,0 +1,4 @@
+div {
+	display: inline-block;
+	display:
+}