Last commit: Thu Oct 8 21:47:46 2020 +0200	Jan Dankert	Fix: Now compatible with PHP 7.4.


      <?php
      
      /**
       * Class for parsing and compiling less files into css
       *
       * @package Less
       * @subpackage parser
       *
       */
     class Less_Parser{
     
     
     	/**
     	 * Default parser options
     	 */
     	public static $default_options = array(
     		'compress'				=> false,			// option - whether to compress
     		'strictUnits'			=> false,			// whether units need to evaluate correctly
     		'strictMath'			=> false,			// whether math has to be within parenthesis
     		'relativeUrls'			=> true,			// option - whether to adjust URL's to be relative
     		'urlArgs'				=> '',				// whether to add args into url tokens
     		'numPrecision'			=> 8,
     
     		'import_dirs'			=> array(),
     		'import_callback'		=> null,
     		'cache_dir'				=> null,
     		'cache_method'			=> 'php', 			// false, 'serialize', 'php', 'var_export', 'callback';
     		'cache_callback_get'	=> null,
     		'cache_callback_set'	=> null,
     
     		'sourceMap'				=> false,			// whether to output a source map
     		'sourceMapBasepath'		=> null,
     		'sourceMapWriteTo'		=> null,
     		'sourceMapURL'			=> null,
     
     		'indentation' 			=> '  ',
     
     		'plugins'				=> array(),
     
     	);
     
     	public static $options = array();
     
     
     	private $input;					// Less input string
     	private $input_len;				// input string length
     	private $pos;					// current index in `input`
     	private $saveStack = array();	// holds state for backtracking
     	private $furthest;
     	private $mb_internal_encoding = ''; // for remember exists value of mbstring.internal_encoding
     
     	/**
     	 * @var Less_Environment
     	 */
     	private $env;
     
     	protected $rules = array();
     
     	private static $imports = array();
     
     	public static $has_extends = false;
     
     	public static $next_id = 0;
     
     	/**
     	 * Filename to contents of all parsed the files
     	 *
     	 * @var array
     	 */
     	public static $contentsMap = array();
     
     
     	/**
     	 * @param Less_Environment|array|null $env
     	 */
     	public function __construct( $env = null ){
     
     		// Top parser on an import tree must be sure there is one "env"
     		// which will then be passed around by reference.
     		if( $env instanceof Less_Environment ){
     			$this->env = $env;
     		}else{
     			$this->SetOptions(Less_Parser::$default_options);
     			$this->Reset( $env );
     		}
     
     		// mbstring.func_overload > 1 bugfix
     		// The encoding value must be set for each source file,
     		// therefore, to conserve resources and improve the speed of this design is taken here
     		if (ini_get('mbstring.func_overload')) {
     			$this->mb_internal_encoding = ini_get('mbstring.internal_encoding');
     			@ini_set('mbstring.internal_encoding', 'ascii');
     		}
     
     	}
     
     
     	/**
     	 * Reset the parser state completely
    	 *
    	 */
    	public function Reset( $options = null ){
    		$this->rules = array();
    		self::$imports = array();
    		self::$has_extends = false;
    		self::$imports = array();
    		self::$contentsMap = array();
    
    		$this->env = new Less_Environment($options);
    		$this->env->Init();
    
    		//set new options
    		if( is_array($options) ){
    			$this->SetOptions(Less_Parser::$default_options);
    			$this->SetOptions($options);
    		}
    	}
    
    	/**
    	 * Set one or more compiler options
    	 *  options: import_dirs, cache_dir, cache_method
    	 *
    	 */
    	public function SetOptions( $options ){
    		foreach($options as $option => $value){
    			$this->SetOption($option,$value);
    		}
    	}
    
    	/**
    	 * Set one compiler option
    	 *
    	 */
    	public function SetOption($option,$value){
    
    		switch($option){
    
    			case 'import_dirs':
    				$this->SetImportDirs($value);
    			return;
    
    			case 'cache_dir':
    				if( is_string($value) ){
    					Less_Cache::SetCacheDir($value);
    					Less_Cache::CheckCacheDir();
    				}
    			return;
    		}
    
    		Less_Parser::$options[$option] = $value;
    	}
    
    	/**
    	 * Registers a new custom function
    	 *
    	 * @param  string   $name     function name
    	 * @param  callable $callback callback
    	 */
    	public function registerFunction($name, $callback) {
    		$this->env->functions[$name] = $callback;
    	}
    
    	/**
    	 * Removed an already registered function
    	 *
    	 * @param  string $name function name
    	 */
    	public function unregisterFunction($name) {
    		if( isset($this->env->functions[$name]) )
    			unset($this->env->functions[$name]);
    	}
    
    
    	/**
    	 * Get the current css buffer
    	 *
    	 * @return string
    	 */
    	public function getCss(){
    
    		$precision = ini_get('precision');
    		@ini_set('precision',16);
    		$locale = setlocale(LC_NUMERIC, 0);
    		setlocale(LC_NUMERIC, "C");
    
    		try {
    
    	 		$root = new Less_Tree_Ruleset(array(), $this->rules );
    			$root->root = true;
    			$root->firstRoot = true;
    
    
    			$this->PreVisitors($root);
    
    			self::$has_extends = false;
    			$evaldRoot = $root->compile($this->env);
    
    
    
    			$this->PostVisitors($evaldRoot);
    
    			if( Less_Parser::$options['sourceMap'] ){
    				$generator = new Less_SourceMap_Generator($evaldRoot, Less_Parser::$contentsMap, Less_Parser::$options );
    				// will also save file
    				// FIXME: should happen somewhere else?
    				$css = $generator->generateCSS();
    			}else{
    				$css = $evaldRoot->toCSS();
    			}
    
    			if( Less_Parser::$options['compress'] ){
    				$css = preg_replace('/(^(\s)+)|((\s)+$)/', '', $css);
    			}
    
    		} catch (Exception $exc) {
    			// Intentional fall-through so we can reset environment
    		}
    
    		//reset php settings
    		@ini_set('precision',$precision);
    		setlocale(LC_NUMERIC, $locale);
    
    		// If you previously defined $this->mb_internal_encoding
    		// is required to return the encoding as it was before
    		if ($this->mb_internal_encoding != '') {
    			@ini_set("mbstring.internal_encoding", $this->mb_internal_encoding);
    			$this->mb_internal_encoding = '';
    		}
    
    		// Rethrow exception after we handled resetting the environment
    		if (!empty($exc)) {
    			throw $exc;
    		}
    
    
    
    		return $css;
    	}
    
    	/**
    	 * Run pre-compile visitors
    	 *
    	 */
    	private function PreVisitors($root){
    
    		if( Less_Parser::$options['plugins'] ){
    			foreach(Less_Parser::$options['plugins'] as $plugin){
    				if( !empty($plugin->isPreEvalVisitor) ){
    					$plugin->run($root);
    				}
    			}
    		}
    	}
    
    
    	/**
    	 * Run post-compile visitors
    	 *
    	 */
    	private function PostVisitors($evaldRoot){
    
    		$visitors = array();
    		$visitors[] = new Less_Visitor_joinSelector();
    		if( self::$has_extends ){
    			$visitors[] = new Less_Visitor_processExtends();
    		}
    		$visitors[] = new Less_Visitor_toCSS();
    
    
    		if( Less_Parser::$options['plugins'] ){
    			foreach(Less_Parser::$options['plugins'] as $plugin){
    				if( property_exists($plugin,'isPreEvalVisitor') && $plugin->isPreEvalVisitor ){
    					continue;
    				}
    
    				if( property_exists($plugin,'isPreVisitor') && $plugin->isPreVisitor ){
    					array_unshift( $visitors, $plugin);
    				}else{
    					$visitors[] = $plugin;
    				}
    			}
    		}
    
    
    		for($i = 0; $i < count($visitors); $i++ ){
    			$visitors[$i]->run($evaldRoot);
    		}
    
    	}
    
    
    	/**
    	 * Parse a Less string into css
    	 *
    	 * @param string $str The string to convert
    	 * @param string $uri_root The url of the file
    	 * @return Less_Tree_Ruleset|Less_Parser
    	 */
    	public function parse( $str, $file_uri = null ){
    
    		if( !$file_uri ){
    			$uri_root = '';
    			$filename = 'anonymous-file-'.Less_Parser::$next_id++.'.less';
    		}else{
    			$file_uri = self::WinPath($file_uri);
    			$filename = $file_uri;
    			$uri_root = dirname($file_uri);
    		}
    
    		$previousFileInfo = $this->env->currentFileInfo;
    		$uri_root = self::WinPath($uri_root);
    		$this->SetFileInfo($filename, $uri_root);
    
    		$this->input = $str;
    		$this->_parse();
    
    		if( $previousFileInfo ){
    			$this->env->currentFileInfo = $previousFileInfo;
    		}
    
    		return $this;
    	}
    
    
    	/**
    	 * Parse a Less string from a given file
    	 *
    	 * @throws Less_Exception_Parser
    	 * @param string $filename The file to parse
    	 * @param string $uri_root The url of the file
    	 * @param bool $returnRoot Indicates whether the return value should be a css string a root node
    	 * @return Less_Tree_Ruleset|Less_Parser
    	 */
    	public function parseFile( $filename, $uri_root = '', $returnRoot = false){
    
    		if( !file_exists($filename) ){
    			$this->Error(sprintf('File `%s` not found.', $filename));
    		}
    
    
    		// fix uri_root?
    		// Instead of The mixture of file path for the first argument and directory path for the second argument has bee
    		if( !$returnRoot && !empty($uri_root) && basename($uri_root) == basename($filename) ){
    			$uri_root = dirname($uri_root);
    		}
    
    
    		$previousFileInfo = $this->env->currentFileInfo;
    
    
    		if( $filename ){
    			$filename = self::WinPath(realpath($filename));
    		}
    		$uri_root = self::WinPath($uri_root);
    
    		$this->SetFileInfo($filename, $uri_root);
    
    		self::AddParsedFile($filename);
    
    		if( $returnRoot ){
    			$rules = $this->GetRules( $filename );
    			$return = new Less_Tree_Ruleset(array(), $rules );
    		}else{
    			$this->_parse( $filename );
    			$return = $this;
    		}
    
    		if( $previousFileInfo ){
    			$this->env->currentFileInfo = $previousFileInfo;
    		}
    
    		return $return;
    	}
    
    
    	/**
    	 * Allows a user to set variables values
    	 * @param array $vars
    	 * @return Less_Parser
    	 */
    	public function ModifyVars( $vars ){
    
    		$this->input = Less_Parser::serializeVars( $vars );
    		$this->_parse();
    
    		return $this;
    	}
    
    
    	/**
    	 * @param string $filename
    	 */
    	public function SetFileInfo( $filename, $uri_root = ''){
    
    		$filename = Less_Environment::normalizePath($filename);
    		$dirname = preg_replace('/[^\/\\\\]*$/','',$filename);
    
    		if( !empty($uri_root) ){
    			$uri_root = rtrim($uri_root,'/').'/';
    		}
    
    		$currentFileInfo = array();
    
    		//entry info
    		if( isset($this->env->currentFileInfo) ){
    			$currentFileInfo['entryPath'] = $this->env->currentFileInfo['entryPath'];
    			$currentFileInfo['entryUri'] = $this->env->currentFileInfo['entryUri'];
    			$currentFileInfo['rootpath'] = $this->env->currentFileInfo['rootpath'];
    
    		}else{
    			$currentFileInfo['entryPath'] = $dirname;
    			$currentFileInfo['entryUri'] = $uri_root;
    			$currentFileInfo['rootpath'] = $dirname;
    		}
    
    		$currentFileInfo['currentDirectory'] = $dirname;
    		$currentFileInfo['currentUri'] = $uri_root.basename($filename);
    		$currentFileInfo['filename'] = $filename;
    		$currentFileInfo['uri_root'] = $uri_root;
    
    
    		//inherit reference
    		if( isset($this->env->currentFileInfo['reference']) && $this->env->currentFileInfo['reference'] ){
    			$currentFileInfo['reference'] = true;
    		}
    
    		$this->env->currentFileInfo = $currentFileInfo;
    	}
    
    
    	/**
    	 * @deprecated 1.5.1.2
    	 *
    	 */
    	public function SetCacheDir( $dir ){
    
    		if( !file_exists($dir) ){
    			if( mkdir($dir) ){
    				return true;
    			}
    			throw new Less_Exception_Parser('Less.php cache directory couldn\'t be created: '.$dir);
    
    		}elseif( !is_dir($dir) ){
    			throw new Less_Exception_Parser('Less.php cache directory doesn\'t exist: '.$dir);
    
    		}elseif( !is_writable($dir) ){
    			throw new Less_Exception_Parser('Less.php cache directory isn\'t writable: '.$dir);
    
    		}else{
    			$dir = self::WinPath($dir);
    			Less_Cache::$cache_dir = rtrim($dir,'/').'/';
    			return true;
    		}
    	}
    
    
    	/**
    	 * Set a list of directories or callbacks the parser should use for determining import paths
    	 *
    	 * @param array $dirs
    	 */
    	public function SetImportDirs( $dirs ){
    		Less_Parser::$options['import_dirs'] = array();
    
    		foreach($dirs as $path => $uri_root){
    
    			$path = self::WinPath($path);
    			if( !empty($path) ){
    				$path = rtrim($path,'/').'/';
    			}
    
    			if ( !is_callable($uri_root) ){
    				$uri_root = self::WinPath($uri_root);
    				if( !empty($uri_root) ){
    					$uri_root = rtrim($uri_root,'/').'/';
    				}
    			}
    
    			Less_Parser::$options['import_dirs'][$path] = $uri_root;
    		}
    	}
    
    	/**
    	 * @param string $file_path
    	 */
    	private function _parse( $file_path = null ){
    		$this->rules = array_merge($this->rules, $this->GetRules( $file_path ));
    	}
    
    
    	/**
    	 * Return the results of parsePrimary for $file_path
    	 * Use cache and save cached results if possible
    	 *
    	 * @param string|null $file_path
    	 */
    	private function GetRules( $file_path ){
    
    		$this->SetInput($file_path);
    
    		$cache_file = $this->CacheFile( $file_path );
    		if( $cache_file ){
    			if( Less_Parser::$options['cache_method'] == 'callback' ){
    				if( is_callable(Less_Parser::$options['cache_callback_get']) ){
    					$cache = call_user_func_array(
    						Less_Parser::$options['cache_callback_get'],
    						array($this, $file_path, $cache_file)
    					);
    
    					if( $cache ){
    						$this->UnsetInput();
    						return $cache;
    					}
    				}
    
    			}elseif( file_exists($cache_file) ){
    				switch(Less_Parser::$options['cache_method']){
    
    					// Using serialize
    					// Faster but uses more memory
    					case 'serialize':
    						$cache = unserialize(file_get_contents($cache_file));
    						if( $cache ){
    							touch($cache_file);
    							$this->UnsetInput();
    							return $cache;
    						}
    					break;
    
    
    					// Using generated php code
    					case 'var_export':
    					case 'php':
    					$this->UnsetInput();
    					return include($cache_file);
    				}
    			}
    		}
    
    		$rules = $this->parsePrimary();
    
    		if( $this->pos < $this->input_len ){
    			throw new Less_Exception_Chunk($this->input, null, $this->furthest, $this->env->currentFileInfo);
    		}
    
    		$this->UnsetInput();
    
    
    		//save the cache
    		if( $cache_file ){
    			if( Less_Parser::$options['cache_method'] == 'callback' ){
    				if( is_callable(Less_Parser::$options['cache_callback_set']) ){
    					call_user_func_array(
    						Less_Parser::$options['cache_callback_set'],
    						array($this, $file_path, $cache_file, $rules)
    					);
    				}
    
    			}else{
    				//msg('write cache file');
    				switch(Less_Parser::$options['cache_method']){
    					case 'serialize':
    						file_put_contents( $cache_file, serialize($rules) );
    					break;
    					case 'php':
    						file_put_contents( $cache_file, '<?php return '.self::ArgString($rules).'; ?>' );
    					break;
    					case 'var_export':
    						//Requires __set_state()
    						file_put_contents( $cache_file, '<?php return '.var_export($rules,true).'; ?>' );
    					break;
    				}
    
    				Less_Cache::CleanCache();
    			}
    		}
    
    		return $rules;
    	}
    
    
    	/**
    	 * Set up the input buffer
    	 *
    	 */
    	public function SetInput( $file_path ){
    
    		if( $file_path ){
    			$this->input = file_get_contents( $file_path );
    		}
    
    		$this->pos = $this->furthest = 0;
    
    		// Remove potential UTF Byte Order Mark
    		$this->input = preg_replace('/\\G\xEF\xBB\xBF/', '', $this->input);
    		$this->input_len = strlen($this->input);
    
    
    		if( Less_Parser::$options['sourceMap'] && $this->env->currentFileInfo ){
    			$uri = $this->env->currentFileInfo['currentUri'];
    			Less_Parser::$contentsMap[$uri] = $this->input;
    		}
    
    	}
    
    
    	/**
    	 * Free up some memory
    	 *
    	 */
    	public function UnsetInput(){
    		unset($this->input, $this->pos, $this->input_len, $this->furthest);
    		$this->saveStack = array();
    	}
    
    
    	public function CacheFile( $file_path ){
    
    		if( $file_path && $this->CacheEnabled() ){
    
    			$env = get_object_vars($this->env);
    			unset($env['frames']);
    
    			$parts = array();
    			$parts[] = $file_path;
    			$parts[] = filesize( $file_path );
    			$parts[] = filemtime( $file_path );
    			$parts[] = $env;
    			$parts[] = Less_Version::cache_version;
    			$parts[] = Less_Parser::$options['cache_method'];
    			return Less_Cache::$cache_dir . Less_Cache::$prefix . base_convert( sha1(json_encode($parts) ), 16, 36) . '.lesscache';
    		}
    	}
    
    
    	static function AddParsedFile($file){
    		self::$imports[] = $file;
    	}
    
    	static function AllParsedFiles(){
    		return self::$imports;
    	}
    
    	/**
    	 * @param string $file
    	 */
    	static function FileParsed($file){
    		return in_array($file,self::$imports);
    	}
    
    
    	function save() {
    		$this->saveStack[] = $this->pos;
    	}
    
    	private function restore() {
    		$this->pos = array_pop($this->saveStack);
    	}
    
    	private function forget(){
    		array_pop($this->saveStack);
    	}
    
    
    	private function isWhitespace($offset = 0) {
    		return preg_match('/\s/',$this->input[ $this->pos + $offset]);
    	}
    
    	/**
    	 * Parse from a token, regexp or string, and move forward if match
    	 *
    	 * @param array $toks
    	 * @return array
    	 */
    	private function match($toks){
    
    		// The match is confirmed, add the match length to `this::pos`,
    		// and consume any extra white-space characters (' ' || '\n')
    		// which come after that. The reason for this is that LeSS's
    		// grammar is mostly white-space insensitive.
    		//
    
    		foreach($toks as $tok){
    
    			$char = $tok[0];
    
    			if( $char === '/' ){
    				$match = $this->MatchReg($tok);
    
    				if( $match ){
    					return count($match) === 1 ? $match[0] : $match;
    				}
    
    			}elseif( $char === '#' ){
    				$match = $this->MatchChar($tok[1]);
    
    			}else{
    				// Non-terminal, match using a function call
    				$match = $this->$tok();
    
    			}
    
    			if( $match ){
    				return $match;
    			}
    		}
    	}
    
    	/**
    	 * @param string[] $toks
    	 *
    	 * @return string
    	 */
    	private function MatchFuncs($toks){
    
    		if( $this->pos < $this->input_len ){
    			foreach($toks as $tok){
    				$match = $this->$tok();
    				if( $match ){
    					return $match;
    				}
    			}
    		}
    
    	}
    
    	// Match a single character in the input,
    	private function MatchChar($tok){
    		if( ($this->pos < $this->input_len) && ($this->input[$this->pos] === $tok) ){
    			$this->skipWhitespace(1);
    			return $tok;
    		}
    	}
    
    	// Match a regexp from the current start point
    	private function MatchReg($tok){
    
    		if( preg_match($tok, $this->input, $match, 0, $this->pos) ){
    			$this->skipWhitespace(strlen($match[0]));
    			return $match;
    		}
    	}
    
    
    	/**
    	 * Same as match(), but don't change the state of the parser,
    	 * just return the match.
    	 *
    	 * @param string $tok
    	 * @return integer
    	 */
    	public function PeekReg($tok){
    		return preg_match($tok, $this->input, $match, 0, $this->pos);
    	}
    
    	/**
    	 * @param string $tok
    	 */
    	public function PeekChar($tok){
    		//return ($this->input[$this->pos] === $tok );
    		return ($this->pos < $this->input_len) && ($this->input[$this->pos] === $tok );
    	}
    
    
    	/**
    	 * @param integer $length
    	 */
    	public function skipWhitespace($length){
    
    		$this->pos += $length;
    
    		for(; $this->pos < $this->input_len; $this->pos++ ){
    			$c = $this->input[$this->pos];
    
    			if( ($c !== "\n") && ($c !== "\r") && ($c !== "\t") && ($c !== ' ') ){
    				break;
    			}
    		}
    	}
    
    
    	/**
    	 * @param string $tok
    	 * @param string|null $msg
    	 */
    	public function expect($tok, $msg = NULL) {
    		$result = $this->match( array($tok) );
    		if (!$result) {
    			$this->Error( $msg	? "Expected '" . $tok . "' got '" . $this->input[$this->pos] . "'" : $msg );
    		} else {
    			return $result;
    		}
    	}
    
    	/**
    	 * @param string $tok
    	 */
    	public function expectChar($tok, $msg = null ){
    		$result = $this->MatchChar($tok);
    		if( !$result ){
    			$this->Error( $msg ? "Expected '" . $tok . "' got '" . $this->input[$this->pos] . "'" : $msg );
    		}else{
    			return $result;
    		}
    	}
    
    	//
    	// Here in, the parsing rules/functions
    	//
    	// The basic structure of the syntax tree generated is as follows:
    	//
    	//   Ruleset ->  Rule -> Value -> Expression -> Entity
    	//
    	// Here's some LESS code:
    	//
    	//	.class {
    	//	  color: #fff;
    	//	  border: 1px solid #000;
    	//	  width: @w + 4px;
    	//	  > .child {...}
    	//	}
    	//
    	// And here's what the parse tree might look like:
    	//
    	//	 Ruleset (Selector '.class', [
    	//		 Rule ("color",  Value ([Expression [Color #fff]]))
    	//		 Rule ("border", Value ([Expression [Dimension 1px][Keyword "solid"][Color #000]]))
    	//		 Rule ("width",  Value ([Expression [Operation "+" [Variable "@w"][Dimension 4px]]]))
    	//		 Ruleset (Selector [Element '>', '.child'], [...])
    	//	 ])
    	//
    	//  In general, most rules will try to parse a token with the `$()` function, and if the return
    	//  value is truly, will return a new node, of the relevant type. Sometimes, we need to check
    	//  first, before parsing, that's when we use `peek()`.
    	//
    
    	//
    	// The `primary` rule is the *entry* and *exit* point of the parser.
    	// The rules here can appear at any level of the parse tree.
    	//
    	// The recursive nature of the grammar is an interplay between the `block`
    	// rule, which represents `{ ... }`, the `ruleset` rule, and this `primary` rule,
    	// as represented by this simplified grammar:
    	//
    	//	 primary  →  (ruleset | rule)+
    	//	 ruleset  →  selector+ block
    	//	 block	→  '{' primary '}'
    	//
    	// Only at one point is the primary rule not called from the
    	// block rule: at the root level.
    	//
    	private function parsePrimary(){
    		$root = array();
    
    		while( true ){
    
    			if( $this->pos >= $this->input_len ){
    				break;
    			}
    
    			$node = $this->parseExtend(true);
    			if( $node ){
    				$root = array_merge($root,$node);
    				continue;
    			}
    
    			//$node = $this->MatchFuncs( array( 'parseMixinDefinition', 'parseRule', 'parseRuleset', 'parseMixinCall', 'parseComment', 'parseDirective'));
    			$node = $this->MatchFuncs( array( 'parseMixinDefinition', 'parseNameValue', 'parseRule', 'parseRuleset', 'parseMixinCall', 'parseComment', 'parseRulesetCall', 'parseDirective'));
    
    			if( $node ){
    				$root[] = $node;
    			}elseif( !$this->MatchReg('/\\G[\s\n;]+/') ){
    				break;
    			}
    
                if( $this->PeekChar('}') ){
    				break;
    			}
    		}
    
    		return $root;
    	}
    
    
    
    	// We create a Comment node for CSS comments `/* */`,
    	// but keep the LeSS comments `//` silent, by just skipping
    	// over them.
    	private function parseComment(){
    
    		if( $this->input[$this->pos] !== '/' ){
    			return;
    		}
    
    		if( $this->input[$this->pos+1] === '/' ){
    			$match = $this->MatchReg('/\\G\/\/.*/');
    			return $this->NewObj4('Less_Tree_Comment',array($match[0], true, $this->pos, $this->env->currentFileInfo));
    		}
    
    		//$comment = $this->MatchReg('/\\G\/\*(?:[^*]|\*+[^\/*])*\*+\/\n?/');
    		$comment = $this->MatchReg('/\\G\/\*(?s).*?\*+\/\n?/');//not the same as less.js to prevent fatal errors
    		if( $comment ){
    			return $this->NewObj4('Less_Tree_Comment',array($comment[0], false, $this->pos, $this->env->currentFileInfo));
    		}
    	}
    
    	private function parseComments(){
    		$comments = array();
    
    		while( $this->pos < $this->input_len ){
    			$comment = $this->parseComment();
    			if( !$comment ){
    				break;
    			}
    
    			$comments[] = $comment;
    		}
    
    		return $comments;
    	}
    
    
    
    	//
    	// A string, which supports escaping " and '
    	//
    	//	 "milky way" 'he\'s the one!'
    	//
    	private function parseEntitiesQuoted() {
    		$j = $this->pos;
    		$e = false;
    		$index = $this->pos;
    
    		if( $this->input[$this->pos] === '~' ){
    			$j++;
    			$e = true; // Escaped strings
    		}
    
    		if( $this->input[$j] != '"' && $this->input[$j] !== "'" ){
    			return;
    		}
    
    		if ($e) {
    			$this->MatchChar('~');
    		}
    
                    // Fix for #124: match escaped newlines
                    //$str = $this->MatchReg('/\\G"((?:[^"\\\\\r\n]|\\\\.)*)"|\'((?:[^\'\\\\\r\n]|\\\\.)*)\'/');
    		$str = $this->MatchReg('/\\G"((?:[^"\\\\\r\n]|\\\\.|\\\\\r\n|\\\\[\n\r\f])*)"|\'((?:[^\'\\\\\r\n]|\\\\.|\\\\\r\n|\\\\[\n\r\f])*)\'/');
    
    		if( $str ){
    			$result = $str[0][0] == '"' ? $str[1] : $str[2];
    			return $this->NewObj5('Less_Tree_Quoted',array($str[0], $result, $e, $index, $this->env->currentFileInfo) );
    		}
    		return;
    	}
    
    
    	//
    	// A catch-all word, such as:
    	//
    	//	 black border-collapse
    	//
    	private function parseEntitiesKeyword(){
    
    		//$k = $this->MatchReg('/\\G[_A-Za-z-][_A-Za-z0-9-]*/');
    		$k = $this->MatchReg('/\\G%|\\G[_A-Za-z-][_A-Za-z0-9-]*/');
    		if( $k ){
    			$k = $k[0];
    			$color = $this->fromKeyword($k);
    			if( $color ){
    				return $color;
    			}
    			return $this->NewObj1('Less_Tree_Keyword',$k);
    		}
    	}
    
    	// duplicate of Less_Tree_Color::FromKeyword
    	private function FromKeyword( $keyword ){
    		$keyword = strtolower($keyword);
    
    		if( Less_Colors::hasOwnProperty($keyword) ){
    			// detect named color
    			return $this->NewObj1('Less_Tree_Color',substr(Less_Colors::color($keyword), 1));
    		}
    
    		if( $keyword === 'transparent' ){
    			return $this->NewObj3('Less_Tree_Color', array( array(0, 0, 0), 0, true));
    		}
    	}
    
    	//
    	// A function call
    	//
    	//	 rgb(255, 0, 255)
    	//
    	// We also try to catch IE's `alpha()`, but let the `alpha` parser
    	// deal with the details.
    	//
   	// The arguments are parsed with the `entities.arguments` parser.
   	//
   	private function parseEntitiesCall(){
   		$index = $this->pos;
   
   		if( !preg_match('/\\G([\w-]+|%|progid:[\w\.]+)\(/', $this->input, $name,0,$this->pos) ){
   			return;
   		}
   		$name = $name[1];
   		$nameLC = strtolower($name);
   
   		if ($nameLC === 'url') {
   			return null;
   		}
   
   		$this->pos += strlen($name);
   
   		if( $nameLC === 'alpha' ){
   			$alpha_ret = $this->parseAlpha();
   			if( $alpha_ret ){
   				return $alpha_ret;
   			}
   		}
   
   		$this->MatchChar('('); // Parse the '(' and consume whitespace.
   
   		$args = $this->parseEntitiesArguments();
   
   		if( !$this->MatchChar(')') ){
   			return;
   		}
   
   		if ($name) {
   			return $this->NewObj4('Less_Tree_Call',array($name, $args, $index, $this->env->currentFileInfo) );
   		}
   	}
   
   	/**
   	 * Parse a list of arguments
   	 *
   	 * @return array
   	 */
   	private function parseEntitiesArguments(){
   
   		$args = array();
   		while( true ){
   			$arg = $this->MatchFuncs( array('parseEntitiesAssignment','parseExpression') );
   			if( !$arg ){
   				break;
   			}
   
   			$args[] = $arg;
   			if( !$this->MatchChar(',') ){
   				break;
   			}
   		}
   		return $args;
   	}
   
   	private function parseEntitiesLiteral(){
   		return $this->MatchFuncs( array('parseEntitiesDimension','parseEntitiesColor','parseEntitiesQuoted','parseUnicodeDescriptor') );
   	}
   
   	// Assignments are argument entities for calls.
   	// They are present in ie filter properties as shown below.
   	//
   	//	 filter: progid:DXImageTransform.Microsoft.Alpha( *opacity=50* )
   	//
   	private function parseEntitiesAssignment() {
   
   		$key = $this->MatchReg('/\\G\w+(?=\s?=)/');
   		if( !$key ){
   			return;
   		}
   
   		if( !$this->MatchChar('=') ){
   			return;
   		}
   
   		$value = $this->parseEntity();
   		if( $value ){
   			return $this->NewObj2('Less_Tree_Assignment',array($key[0], $value));
   		}
   	}
   
   	//
   	// Parse url() tokens
   	//
   	// We use a specific rule for urls, because they don't really behave like
   	// standard function calls. The difference is that the argument doesn't have
   	// to be enclosed within a string, so it can't be parsed as an Expression.
   	//
   	private function parseEntitiesUrl(){
   
   
   		if( $this->input[$this->pos] !== 'u' || !$this->matchReg('/\\Gurl\(/') ){
   			return;
   		}
   
   		$value = $this->match( array('parseEntitiesQuoted','parseEntitiesVariable','/\\Gdata\:.*?[^\)]+/','/\\G(?:(?:\\\\[\(\)\'"])|[^\(\)\'"])+/') );
   		if( !$value ){
   			$value = '';
   		}
   
   
   		$this->expectChar(')');
   
   
   		if( isset($value->value) || $value instanceof Less_Tree_Variable ){
   			return $this->NewObj2('Less_Tree_Url',array($value, $this->env->currentFileInfo));
   		}
   
   		return $this->NewObj2('Less_Tree_Url', array( $this->NewObj1('Less_Tree_Anonymous',$value), $this->env->currentFileInfo) );
   	}
   
   
   	//
   	// A Variable entity, such as `@fink`, in
   	//
   	//	 width: @fink + 2px
   	//
   	// We use a different parser for variable definitions,
   	// see `parsers.variable`.
   	//
   	private function parseEntitiesVariable(){
   		$index = $this->pos;
   		if ($this->PeekChar('@') && ($name = $this->MatchReg('/\\G@@?[\w-]+/'))) {
   			return $this->NewObj3('Less_Tree_Variable', array( $name[0], $index, $this->env->currentFileInfo));
   		}
   	}
   
   
   	// A variable entity useing the protective {} e.g. @{var}
   	private function parseEntitiesVariableCurly() {
   		$index = $this->pos;
   
   		if( $this->input_len > ($this->pos+1) && $this->input[$this->pos] === '@' && ($curly = $this->MatchReg('/\\G@\{([\w-]+)\}/')) ){
   			return $this->NewObj3('Less_Tree_Variable',array('@'.$curly[1], $index, $this->env->currentFileInfo));
   		}
   	}
   
   	//
   	// A Hexadecimal color
   	//
   	//	 #4F3C2F
   	//
   	// `rgb` and `hsl` colors are parsed through the `entities.call` parser.
   	//
   	private function parseEntitiesColor(){
   		if ($this->PeekChar('#') && ($rgb = $this->MatchReg('/\\G#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})/'))) {
   			return $this->NewObj1('Less_Tree_Color',$rgb[1]);
   		}
   	}
   
   	//
   	// A Dimension, that is, a number and a unit
   	//
   	//	 0.5em 95%
   	//
   	private function parseEntitiesDimension(){
   
   		$c = @ord($this->input[$this->pos]);
   
   		//Is the first char of the dimension 0-9, '.', '+' or '-'
   		if (($c > 57 || $c < 43) || $c === 47 || $c == 44){
   			return;
   		}
   
   		$value = $this->MatchReg('/\\G([+-]?\d*\.?\d+)(%|[a-z]+)?/');
   		if( $value ){
   
   			if( isset($value[2]) ){
   				return $this->NewObj2('Less_Tree_Dimension', array($value[1],$value[2]));
   			}
   			return $this->NewObj1('Less_Tree_Dimension',$value[1]);
   		}
   	}
   
   
   	//
   	// A unicode descriptor, as is used in unicode-range
   	//
   	// U+0?? or U+00A1-00A9
   	//
   	function parseUnicodeDescriptor() {
   		$ud = $this->MatchReg('/\\G(U\+[0-9a-fA-F?]+)(\-[0-9a-fA-F?]+)?/');
   		if( $ud ){
   			return $this->NewObj1('Less_Tree_UnicodeDescriptor', $ud[0]);
   		}
   	}
   
   
   	//
   	// JavaScript code to be evaluated
   	//
   	//	 `window.location.href`
   	//
   	private function parseEntitiesJavascript(){
   		$e = false;
   		$j = $this->pos;
   		if( $this->input[$j] === '~' ){
   			$j++;
   			$e = true;
   		}
   		if( $this->input[$j] !== '`' ){
   			return;
   		}
   		if( $e ){
   			$this->MatchChar('~');
   		}
   		$str = $this->MatchReg('/\\G`([^`]*)`/');
   		if( $str ){
   			return $this->NewObj3('Less_Tree_Javascript', array($str[1], $this->pos, $e));
   		}
   	}
   
   
   	//
   	// The variable part of a variable definition. Used in the `rule` parser
   	//
   	//	 @fink:
   	//
   	private function parseVariable(){
   		if ($this->PeekChar('@') && ($name = $this->MatchReg('/\\G(@[\w-]+)\s*:/'))) {
   			return $name[1];
   		}
   	}
   
   
   	//
   	// The variable part of a variable definition. Used in the `rule` parser
   	//
   	// @fink();
   	//
   	private function parseRulesetCall(){
   
   		if( $this->input[$this->pos] === '@' && ($name = $this->MatchReg('/\\G(@[\w-]+)\s*\(\s*\)\s*;/')) ){
   			return $this->NewObj1('Less_Tree_RulesetCall', $name[1] );
   		}
   	}
   
   
   	//
   	// extend syntax - used to extend selectors
   	//
   	function parseExtend($isRule = false){
   
   		$index = $this->pos;
   		$extendList = array();
   
   
   		if( !$this->MatchReg( $isRule ? '/\\G&:extend\(/' : '/\\G:extend\(/' ) ){ return; }
   
   		do{
   			$option = null;
   			$elements = array();
   			while( true ){
   				$option = $this->MatchReg('/\\G(all)(?=\s*(\)|,))/');
   				if( $option ){ break; }
   				$e = $this->parseElement();
   				if( !$e ){ break; }
   				$elements[] = $e;
   			}
   
   			if( $option ){
   				$option = $option[1];
   			}
   
   			$extendList[] = $this->NewObj3('Less_Tree_Extend', array( $this->NewObj1('Less_Tree_Selector',$elements), $option, $index ));
   
   		}while( $this->MatchChar(",") );
   
   		$this->expect('/\\G\)/');
   
   		if( $isRule ){
   			$this->expect('/\\G;/');
   		}
   
   		return $extendList;
   	}
   
   
   	//
   	// A Mixin call, with an optional argument list
   	//
   	//	 #mixins > .square(#fff);
   	//	 .rounded(4px, black);
   	//	 .button;
   	//
   	// The `while` loop is there because mixins can be
   	// namespaced, but we only support the child and descendant
   	// selector for now.
   	//
   	private function parseMixinCall(){
   
   		$char = $this->input[$this->pos];
   		if( $char !== '.' && $char !== '#' ){
   			return;
   		}
   
   		$index = $this->pos;
   		$this->save(); // stop us absorbing part of an invalid selector
   
   		$elements = $this->parseMixinCallElements();
   
   		if( $elements ){
   
   			if( $this->MatchChar('(') ){
   				$returned = $this->parseMixinArgs(true);
   				$args = $returned['args'];
   				$this->expectChar(')');
   			}else{
   				$args = array();
   			}
   
   			$important = $this->parseImportant();
   
   			if( $this->parseEnd() ){
   				$this->forget();
   				return $this->NewObj5('Less_Tree_Mixin_Call', array( $elements, $args, $index, $this->env->currentFileInfo, $important));
   			}
   		}
   
   		$this->restore();
   	}
   
   
   	private function parseMixinCallElements(){
   		$elements = array();
   		$c = null;
   
   		while( true ){
   			$elemIndex = $this->pos;
   			$e = $this->MatchReg('/\\G[#.](?:[\w-]|\\\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/');
   			if( !$e ){
   				break;
   			}
   			$elements[] = $this->NewObj4('Less_Tree_Element', array($c, $e[0], $elemIndex, $this->env->currentFileInfo));
   			$c = $this->MatchChar('>');
   		}
   
   		return $elements;
   	}
   
   
   
   	/**
   	 * @param boolean $isCall
   	 */
   	private function parseMixinArgs( $isCall ){
   		$expressions = array();
   		$argsSemiColon = array();
   		$isSemiColonSeperated = null;
   		$argsComma = array();
   		$expressionContainsNamed = null;
   		$name = null;
   		$returner = array('args'=>array(), 'variadic'=> false);
   
   		$this->save();
   
   		while( true ){
   			if( $isCall ){
   				$arg = $this->MatchFuncs( array( 'parseDetachedRuleset','parseExpression' ) );
   			} else {
   				$this->parseComments();
   				if( $this->input[ $this->pos ] === '.' && $this->MatchReg('/\\G\.{3}/') ){
   					$returner['variadic'] = true;
   					if( $this->MatchChar(";") && !$isSemiColonSeperated ){
   						$isSemiColonSeperated = true;
   					}
   
   					if( $isSemiColonSeperated ){
   						$argsSemiColon[] = array('variadic'=>true);
   					}else{
   						$argsComma[] = array('variadic'=>true);
   					}
   					break;
   				}
   				$arg = $this->MatchFuncs( array('parseEntitiesVariable','parseEntitiesLiteral','parseEntitiesKeyword') );
   			}
   
   			if( !$arg ){
   				break;
   			}
   
   
   			$nameLoop = null;
   			if( $arg instanceof Less_Tree_Expression ){
   				$arg->throwAwayComments();
   			}
   			$value = $arg;
   			$val = null;
   
   			if( $isCall ){
   				// Variable
   				if( property_exists($arg,'value') && count($arg->value) == 1 ){
   					$val = $arg->value[0];
   				}
   			} else {
   				$val = $arg;
   			}
   
   
   			if( $val instanceof Less_Tree_Variable ){
   
   				if( $this->MatchChar(':') ){
   					if( $expressions ){
   						if( $isSemiColonSeperated ){
   							$this->Error('Cannot mix ; and , as delimiter types');
   						}
   						$expressionContainsNamed = true;
   					}
   
   					// we do not support setting a ruleset as a default variable - it doesn't make sense
   					// However if we do want to add it, there is nothing blocking it, just don't error
   					// and remove isCall dependency below
   					$value = null;
   					if( $isCall ){
   						$value = $this->parseDetachedRuleset();
   					}
   					if( !$value ){
   						$value = $this->parseExpression();
   					}
   
   					if( !$value ){
   						if( $isCall ){
   							$this->Error('could not understand value for named argument');
   						} else {
   							$this->restore();
   							$returner['args'] = array();
   							return $returner;
   						}
   					}
   
   					$nameLoop = ($name = $val->name);
   				}elseif( !$isCall && $this->MatchReg('/\\G\.{3}/') ){
   					$returner['variadic'] = true;
   					if( $this->MatchChar(";") && !$isSemiColonSeperated ){
   						$isSemiColonSeperated = true;
   					}
   					if( $isSemiColonSeperated ){
   						$argsSemiColon[] = array('name'=> $arg->name, 'variadic' => true);
   					}else{
   						$argsComma[] = array('name'=> $arg->name, 'variadic' => true);
   					}
   					break;
   				}elseif( !$isCall ){
   					$name = $nameLoop = $val->name;
   					$value = null;
   				}
   			}
   
   			if( $value ){
   				$expressions[] = $value;
   			}
   
   			$argsComma[] = array('name'=>$nameLoop, 'value'=>$value );
   
   			if( $this->MatchChar(',') ){
   				continue;
   			}
   
   			if( $this->MatchChar(';') || $isSemiColonSeperated ){
   
   				if( $expressionContainsNamed ){
   					$this->Error('Cannot mix ; and , as delimiter types');
   				}
   
   				$isSemiColonSeperated = true;
   
   				if( count($expressions) > 1 ){
   					$value = $this->NewObj1('Less_Tree_Value', $expressions);
   				}
   				$argsSemiColon[] = array('name'=>$name, 'value'=>$value );
   
   				$name = null;
   				$expressions = array();
   				$expressionContainsNamed = false;
   			}
   		}
   
   		$this->forget();
   		$returner['args'] = ($isSemiColonSeperated ? $argsSemiColon : $argsComma);
   		return $returner;
   	}
   
   
   
   	//
   	// A Mixin definition, with a list of parameters
   	//
   	//	 .rounded (@radius: 2px, @color) {
   	//		...
   	//	 }
   	//
   	// Until we have a finer grained state-machine, we have to
   	// do a look-ahead, to make sure we don't have a mixin call.
   	// See the `rule` function for more information.
   	//
   	// We start by matching `.rounded (`, and then proceed on to
   	// the argument list, which has optional default values.
   	// We store the parameters in `params`, with a `value` key,
   	// if there is a value, such as in the case of `@radius`.
   	//
   	// Once we've got our params list, and a closing `)`, we parse
   	// the `{...}` block.
   	//
   	private function parseMixinDefinition(){
   		$cond = null;
   
   		$char = $this->input[$this->pos];
   		if( ($char !== '.' && $char !== '#') || ($char === '{' && $this->PeekReg('/\\G[^{]*\}/')) ){
   			return;
   		}
   
   		$this->save();
   
   		$match = $this->MatchReg('/\\G([#.](?:[\w-]|\\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+)\s*\(/');
   		if( $match ){
   			$name = $match[1];
   
   			$argInfo = $this->parseMixinArgs( false );
   			$params = $argInfo['args'];
   			$variadic = $argInfo['variadic'];
   
   
   			// .mixincall("@{a}");
   			// looks a bit like a mixin definition..
   			// also
   			// .mixincall(@a: {rule: set;});
   			// so we have to be nice and restore
   			if( !$this->MatchChar(')') ){
   				$this->furthest = $this->pos;
   				$this->restore();
   				return;
   			}
   
   
   			$this->parseComments();
   
   			if ($this->MatchReg('/\\Gwhen/')) { // Guard
   				$cond = $this->expect('parseConditions', 'Expected conditions');
   			}
   
   			$ruleset = $this->parseBlock();
   
   			if( is_array($ruleset) ){
   				$this->forget();
   				return $this->NewObj5('Less_Tree_Mixin_Definition', array( $name, $params, $ruleset, $cond, $variadic));
   			}
   
   			$this->restore();
   		}else{
   			$this->forget();
   		}
   	}
   
   	//
   	// Entities are the smallest recognized token,
   	// and can be found inside a rule's value.
   	//
   	private function parseEntity(){
   
   		return $this->MatchFuncs( array('parseEntitiesLiteral','parseEntitiesVariable','parseEntitiesUrl','parseEntitiesCall','parseEntitiesKeyword','parseEntitiesJavascript','parseComment') );
   	}
   
   	//
   	// A Rule terminator. Note that we use `peek()` to check for '}',
   	// because the `block` rule will be expecting it, but we still need to make sure
   	// it's there, if ';' was ommitted.
   	//
   	private function parseEnd(){
   		return $this->MatchChar(';') || $this->PeekChar('}');
   	}
   
   	//
   	// IE's alpha function
   	//
   	//	 alpha(opacity=88)
   	//
   	private function parseAlpha(){
   
   		if ( ! $this->MatchReg('/\\G\(opacity=/i')) {
   			return;
   		}
   
   		$value = $this->MatchReg('/\\G[0-9]+/');
   		if( $value ){
   			$value = $value[0];
   		}else{
   			$value = $this->parseEntitiesVariable();
   			if( !$value ){
   				return;
   			}
   		}
   
   		$this->expectChar(')');
   		return $this->NewObj1('Less_Tree_Alpha',$value);
   	}
   
   
   	//
   	// A Selector Element
   	//
   	//	 div
   	//	 + h1
   	//	 #socks
   	//	 input[type="text"]
   	//
   	// Elements are the building blocks for Selectors,
   	// they are made out of a `Combinator` (see combinator rule),
   	// and an element name, such as a tag a class, or `*`.
   	//
   	private function parseElement(){
   		$c = $this->parseCombinator();
   		$index = $this->pos;
   
   		$e = $this->match( array('/\\G(?:\d+\.\d+|\d+)%/', '/\\G(?:[.#]?|:*)(?:[\w-]|[^\x00-\x9f]|\\\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/',
   			'#*', '#&', 'parseAttribute', '/\\G\([^()@]+\)/', '/\\G[\.#](?=@)/', 'parseEntitiesVariableCurly') );
   
   		if( is_null($e) ){
   			$this->save();
   			if( $this->MatchChar('(') ){
   				if( ($v = $this->parseSelector()) && $this->MatchChar(')') ){
   					$e = $this->NewObj1('Less_Tree_Paren',$v);
   					$this->forget();
   				}else{
   					$this->restore();
   				}
   			}else{
   				$this->forget();
   			}
   		}
   
   		if( !is_null($e) ){
   			return $this->NewObj4('Less_Tree_Element',array( $c, $e, $index, $this->env->currentFileInfo));
   		}
   	}
   
   	//
   	// Combinators combine elements together, in a Selector.
   	//
   	// Because our parser isn't white-space sensitive, special care
   	// has to be taken, when parsing the descendant combinator, ` `,
   	// as it's an empty space. We have to check the previous character
   	// in the input, to see if it's a ` ` character.
   	//
   	private function parseCombinator(){
   		if( $this->pos < $this->input_len ){
   			$c = $this->input[$this->pos];
   			if ($c === '>' || $c === '+' || $c === '~' || $c === '|' || $c === '^' ){
   
   				$this->pos++;
   				if( $this->input[$this->pos] === '^' ){
   					$c = '^^';
   					$this->pos++;
   				}
   
   				$this->skipWhitespace(0);
   
   				return $c;
   			}
   
   			if( $this->pos > 0 && $this->isWhitespace(-1) ){
   				return ' ';
   			}
   		}
   	}
   
   	//
   	// A CSS selector (see selector below)
   	// with less extensions e.g. the ability to extend and guard
   	//
   	private function parseLessSelector(){
   		return $this->parseSelector(true);
   	}
   
   	//
   	// A CSS Selector
   	//
   	//	 .class > div + h1
   	//	 li a:hover
   	//
   	// Selectors are made out of one or more Elements, see above.
   	//
   	private function parseSelector( $isLess = false ){
   		$elements = array();
   		$extendList = array();
   		$condition = null;
   		$when = false;
   		$extend = false;
   		$e = null;
   		$c = null;
   		$index = $this->pos;
   
   		while( ($isLess && ($extend = $this->parseExtend())) || ($isLess && ($when = $this->MatchReg('/\\Gwhen/') )) || ($e = $this->parseElement()) ){
   			if( $when ){
   				$condition = $this->expect('parseConditions', 'expected condition');
   			}elseif( $condition ){
   				//error("CSS guard can only be used at the end of selector");
   			}elseif( $extend ){
   				$extendList = array_merge($extendList,$extend);
   			}else{
   				//if( count($extendList) ){
   					//error("Extend can only be used at the end of selector");
   				//}
   				if( $this->pos < $this->input_len ){
   					$c = $this->input[ $this->pos ];
   				}
   				$elements[] = $e;
   				$e = null;
   			}
   
   			if( $c === '{' || $c === '}' || $c === ';' || $c === ',' || $c === ')') { break; }
   		}
   
   		if( $elements ){
   			return $this->NewObj5('Less_Tree_Selector',array($elements, $extendList, $condition, $index, $this->env->currentFileInfo));
   		}
   		if( $extendList ) {
   			$this->Error('Extend must be used to extend a selector, it cannot be used on its own');
   		}
   	}
   
   	private function parseTag(){
   		return ( $tag = $this->MatchReg('/\\G[A-Za-z][A-Za-z-]*[0-9]?/') ) ? $tag : $this->MatchChar('*');
   	}
   
   	private function parseAttribute(){
   
   		$val = null;
   
   		if( !$this->MatchChar('[') ){
   			return;
   		}
   
   		$key = $this->parseEntitiesVariableCurly();
   		if( !$key ){
   			$key = $this->expect('/\\G(?:[_A-Za-z0-9-\*]*\|)?(?:[_A-Za-z0-9-]|\\\\.)+/');
   		}
   
   		$op = $this->MatchReg('/\\G[|~*$^]?=/');
   		if( $op ){
   			$val = $this->match( array('parseEntitiesQuoted','/\\G[0-9]+%/','/\\G[\w-]+/','parseEntitiesVariableCurly') );
   		}
   
   		$this->expectChar(']');
   
   		return $this->NewObj3('Less_Tree_Attribute',array( $key, $op[0], $val));
   	}
   
   	//
   	// The `block` rule is used by `ruleset` and `mixin.definition`.
   	// It's a wrapper around the `primary` rule, with added `{}`.
   	//
   	private function parseBlock(){
   		if( $this->MatchChar('{') ){
   			$content = $this->parsePrimary();
   			if( $this->MatchChar('}') ){
   				return $content;
   			}
   		}
   	}
   
   	private function parseBlockRuleset(){
   		$block = $this->parseBlock();
   
   		if( $block ){
   			$block = $this->NewObj2('Less_Tree_Ruleset',array( null, $block));
   		}
   
   		return $block;
   	}
   
   	private function parseDetachedRuleset(){
   		$blockRuleset = $this->parseBlockRuleset();
   		if( $blockRuleset ){
   			return $this->NewObj1('Less_Tree_DetachedRuleset',$blockRuleset);
   		}
   	}
   
   	//
   	// div, .class, body > p {...}
   	//
   	private function parseRuleset(){
   		$selectors = array();
   
   		$this->save();
   
   		while( true ){
   			$s = $this->parseLessSelector();
   			if( !$s ){
   				break;
   			}
   			$selectors[] = $s;
   			$this->parseComments();
   
   			if( $s->condition && count($selectors) > 1 ){
   				$this->Error('Guards are only currently allowed on a single selector.');
   			}
   
   			if( !$this->MatchChar(',') ){
   				break;
   			}
   			if( $s->condition ){
   				$this->Error('Guards are only currently allowed on a single selector.');
   			}
   			$this->parseComments();
   		}
   
   
   		if( $selectors ){
   			$rules = $this->parseBlock();
   			if( is_array($rules) ){
   				$this->forget();
   				return $this->NewObj2('Less_Tree_Ruleset',array( $selectors, $rules)); //Less_Environment::$strictImports
   			}
   		}
   
   		// Backtrack
   		$this->furthest = $this->pos;
   		$this->restore();
   	}
   
   	/**
   	 * Custom less.php parse function for finding simple name-value css pairs
   	 * ex: width:100px;
   	 *
   	 */
   	private function parseNameValue(){
   
   		$index = $this->pos;
   		$this->save();
   
   
   		//$match = $this->MatchReg('/\\G([a-zA-Z\-]+)\s*:\s*((?:\'")?[a-zA-Z0-9\-% \.,!]+?(?:\'")?)\s*([;}])/');
   		$match = $this->MatchReg('/\\G([a-zA-Z\-]+)\s*:\s*([\'"]?[#a-zA-Z0-9\-%\.,]+?[\'"]?) *(! *important)?\s*([;}])/');
   		if( $match ){
   
   			if( $match[4] == '}' ){
   				$this->pos = $index + strlen($match[0])-1;
   			}
   
   			if( $match[3] ){
   				$match[2] .= ' !important';
   			}
   
   			return $this->NewObj4('Less_Tree_NameValue',array( $match[1], $match[2], $index, $this->env->currentFileInfo));
   		}
   
   		$this->restore();
   	}
   
   
   	private function parseRule( $tryAnonymous = null ){
   
   		$merge = false;
   		$startOfRule = $this->pos;
   
   		$c = $this->input[$this->pos];
   		if( $c === '.' || $c === '#' || $c === '&' ){
   			return;
   		}
   
   		$this->save();
   		$name = $this->MatchFuncs( array('parseVariable','parseRuleProperty'));
   
   		if( $name ){
   
   			$isVariable = is_string($name);
   
   			$value = null;
   			if( $isVariable ){
   				$value = $this->parseDetachedRuleset();
   			}
   
   			$important = null;
   			if( !$value ){
   
   				// prefer to try to parse first if its a variable or we are compressing
   				// but always fallback on the other one
   				//if( !$tryAnonymous && is_string($name) && $name[0] === '@' ){
   				if( !$tryAnonymous && (Less_Parser::$options['compress'] || $isVariable) ){
   					$value = $this->MatchFuncs( array('parseValue','parseAnonymousValue'));
   				}else{
   					$value = $this->MatchFuncs( array('parseAnonymousValue','parseValue'));
   				}
   
   				$important = $this->parseImportant();
   
   				// a name returned by this.ruleProperty() is always an array of the form:
   				// [string-1, ..., string-n, ""] or [string-1, ..., string-n, "+"]
   				// where each item is a tree.Keyword or tree.Variable
   				if( !$isVariable && is_array($name) ){
   					$nm = array_pop($name);
   					if( $nm->value ){
   						$merge = $nm->value;
   					}
   				}
   			}
   
   
   			if( $value && $this->parseEnd() ){
   				$this->forget();
   				return $this->NewObj6('Less_Tree_Rule',array( $name, $value, $important, $merge, $startOfRule, $this->env->currentFileInfo));
   			}else{
   				$this->furthest = $this->pos;
   				$this->restore();
   				if( $value && !$tryAnonymous ){
   					return $this->parseRule(true);
   				}
   			}
   		}else{
   			$this->forget();
   		}
   	}
   
   	function parseAnonymousValue(){
   
   		if( preg_match('/\\G([^@+\/\'"*`(;{}-]*);/',$this->input, $match, 0, $this->pos) ){
   			$this->pos += strlen($match[1]);
   			return $this->NewObj1('Less_Tree_Anonymous',$match[1]);
   		}
   	}
   
   	//
   	// An @import directive
   	//
   	//	 @import "lib";
   	//
   	// Depending on our environment, importing is done differently:
   	// In the browser, it's an XHR request, in Node, it would be a
   	// file-system operation. The function used for importing is
   	// stored in `import`, which we pass to the Import constructor.
   	//
   	private function parseImport(){
   
   		$this->save();
   
   		$dir = $this->MatchReg('/\\G@import?\s+/');
   
   		if( $dir ){
   			$options = $this->parseImportOptions();
   			$path = $this->MatchFuncs( array('parseEntitiesQuoted','parseEntitiesUrl'));
   
   			if( $path ){
   				$features = $this->parseMediaFeatures();
   				if( $this->MatchChar(';') ){
   					if( $features ){
   						$features = $this->NewObj1('Less_Tree_Value',$features);
   					}
   
   					$this->forget();
   					return $this->NewObj5('Less_Tree_Import',array( $path, $features, $options, $this->pos, $this->env->currentFileInfo));
   				}
   			}
   		}
   
   		$this->restore();
   	}
   
   	private function parseImportOptions(){
   
   		$options = array();
   
   		// list of options, surrounded by parens
   		if( !$this->MatchChar('(') ){
   			return $options;
   		}
   		do{
   			$optionName = $this->parseImportOption();
   			if( $optionName ){
   				$value = true;
   				switch( $optionName ){
   					case "css":
   						$optionName = "less";
   						$value = false;
   					break;
   					case "once":
   						$optionName = "multiple";
   						$value = false;
   					break;
   				}
   				$options[$optionName] = $value;
   				if( !$this->MatchChar(',') ){ break; }
   			}
   		}while( $optionName );
   		$this->expectChar(')');
   		return $options;
   	}
   
   	private function parseImportOption(){
   		$opt = $this->MatchReg('/\\G(less|css|multiple|once|inline|reference|optional)/');
   		if( $opt ){
   			return $opt[1];
   		}
   	}
   
   	private function parseMediaFeature() {
   		$nodes = array();
   
   		do{
   			$e = $this->MatchFuncs(array('parseEntitiesKeyword','parseEntitiesVariable'));
   			if( $e ){
   				$nodes[] = $e;
   			} elseif ($this->MatchChar('(')) {
   				$p = $this->parseProperty();
   				$e = $this->parseValue();
   				if ($this->MatchChar(')')) {
   					if ($p && $e) {
   						$r = $this->NewObj7('Less_Tree_Rule', array( $p, $e, null, null, $this->pos, $this->env->currentFileInfo, true));
   						$nodes[] = $this->NewObj1('Less_Tree_Paren',$r);
   					} elseif ($e) {
   						$nodes[] = $this->NewObj1('Less_Tree_Paren',$e);
   					} else {
   						return null;
   					}
   				} else
   					return null;
   			}
   		} while ($e);
   
   		if ($nodes) {
   			return $this->NewObj1('Less_Tree_Expression',$nodes);
   		}
   	}
   
   	private function parseMediaFeatures() {
   		$features = array();
   
   		do{
   			$e = $this->parseMediaFeature();
   			if( $e ){
   				$features[] = $e;
   				if (!$this->MatchChar(',')) break;
   			}else{
   				$e = $this->parseEntitiesVariable();
   				if( $e ){
   					$features[] = $e;
   					if (!$this->MatchChar(',')) break;
   				}
   			}
   		} while ($e);
   
   		return $features ? $features : null;
   	}
   
   	private function parseMedia() {
   		if( $this->MatchReg('/\\G@media/') ){
   			$features = $this->parseMediaFeatures();
   			$rules = $this->parseBlock();
   
   			if( is_array($rules) ){
   				return $this->NewObj4('Less_Tree_Media',array( $rules, $features, $this->pos, $this->env->currentFileInfo));
   			}
   		}
   	}
   
   
   	//
   	// A CSS Directive
   	//
   	// @charset "utf-8";
   	//
   	private function parseDirective(){
   
   		if( !$this->PeekChar('@') ){
   			return;
   		}
   
   		$rules = null;
   		$index = $this->pos;
   		$hasBlock = true;
   		$hasIdentifier = false;
   		$hasExpression = false;
   		$hasUnknown = false;
   
   
   		$value = $this->MatchFuncs(array('parseImport','parseMedia'));
   		if( $value ){
   			return $value;
   		}
   
   		$this->save();
   
   		$name = $this->MatchReg('/\\G@[a-z-]+/');
   
   		if( !$name ) return;
   		$name = $name[0];
   
   
   		$nonVendorSpecificName = $name;
   		$pos = strpos($name,'-', 2);
   		if( $name[1] == '-' && $pos > 0 ){
   			$nonVendorSpecificName = "@" . substr($name, $pos + 1);
   		}
   
   
   		switch( $nonVendorSpecificName ){
   			/*
   			case "@font-face":
   			case "@viewport":
   			case "@top-left":
   			case "@top-left-corner":
   			case "@top-center":
   			case "@top-right":
   			case "@top-right-corner":
   			case "@bottom-left":
   			case "@bottom-left-corner":
   			case "@bottom-center":
   			case "@bottom-right":
   			case "@bottom-right-corner":
   			case "@left-top":
   			case "@left-middle":
   			case "@left-bottom":
   			case "@right-top":
   			case "@right-middle":
   			case "@right-bottom":
   			hasBlock = true;
   			break;
   			*/
   			case "@charset":
   				$hasIdentifier = true;
   				$hasBlock = false;
   				break;
   			case "@namespace":
   				$hasExpression = true;
   				$hasBlock = false;
   				break;
   			case "@keyframes":
   				$hasIdentifier = true;
   				break;
   			case "@host":
   			case "@page":
   			case "@document":
   			case "@supports":
   				$hasUnknown = true;
   				break;
   		}
   
   		if( $hasIdentifier ){
   			$value = $this->parseEntity();
   			if( !$value ){
   				$this->error("expected " . $name . " identifier");
   			}
   		} else if( $hasExpression ){
   			$value = $this->parseExpression();
   			if( !$value ){
   				$this->error("expected " . $name. " expression");
   			}
   		} else if ($hasUnknown) {
   
   			$value = $this->MatchReg('/\\G[^{;]+/');
   			if( $value ){
   				$value = $this->NewObj1('Less_Tree_Anonymous',trim($value[0]));
   			}
   		}
   
   		if( $hasBlock ){
   			$rules = $this->parseBlockRuleset();
   		}
   
   		if( $rules || (!$hasBlock && $value && $this->MatchChar(';'))) {
   			$this->forget();
   			return $this->NewObj5('Less_Tree_Directive',array($name, $value, $rules, $index, $this->env->currentFileInfo));
   		}
   
   		$this->restore();
   	}
   
   
   	//
   	// A Value is a comma-delimited list of Expressions
   	//
   	//	 font-family: Baskerville, Georgia, serif;
   	//
   	// In a Rule, a Value represents everything after the `:`,
   	// and before the `;`.
   	//
   	private function parseValue(){
   		$expressions = array();
   
   		do{
   			$e = $this->parseExpression();
   			if( $e ){
   				$expressions[] = $e;
   				if (! $this->MatchChar(',')) {
   					break;
   				}
   			}
   		}while($e);
   
   		if( $expressions ){
   			return $this->NewObj1('Less_Tree_Value',$expressions);
   		}
   	}
   
   	private function parseImportant (){
   		if( $this->PeekChar('!') && $this->MatchReg('/\\G! *important/') ){
   			return ' !important';
   		}
   	}
   
   	private function parseSub (){
   
   		if( $this->MatchChar('(') ){
   			$a = $this->parseAddition();
   			if( $a ){
   				$this->expectChar(')');
   				return $this->NewObj2('Less_Tree_Expression',array( array($a), true) ); //instead of $e->parens = true so the value is cached
   			}
   		}
   	}
   
   
   	/**
   	 * Parses multiplication operation
   	 *
   	 * @return Less_Tree_Operation|null
   	 */
   	function parseMultiplication(){
   
   		$return = $m = $this->parseOperand();
   		if( $return ){
   			while( true ){
   
   				$isSpaced = $this->isWhitespace( -1 );
   
   				if( $this->PeekReg('/\\G\/[*\/]/') ){
   					break;
   				}
   
   				$op = $this->MatchChar('/');
   				if( !$op ){
   					$op = $this->MatchChar('*');
   					if( !$op ){
   						break;
   					}
   				}
   
   				$a = $this->parseOperand();
   
   				if(!$a) { break; }
   
   				$m->parensInOp = true;
   				$a->parensInOp = true;
   				$return = $this->NewObj3('Less_Tree_Operation',array( $op, array( $return, $a ), $isSpaced) );
   			}
   		}
   		return $return;
   
   	}
   
   
   	/**
   	 * Parses an addition operation
   	 *
   	 * @return Less_Tree_Operation|null
   	 */
   	private function parseAddition (){
   
   		$return = $m = $this->parseMultiplication();
   		if( $return ){
   			while( true ){
   
   				$isSpaced = $this->isWhitespace( -1 );
   
   				$op = $this->MatchReg('/\\G[-+]\s+/');
   				if( $op ){
   					$op = $op[0];
   				}else{
   					if( !$isSpaced ){
   						$op = $this->match(array('#+','#-'));
   					}
   					if( !$op ){
   						break;
   					}
   				}
   
   				$a = $this->parseMultiplication();
   				if( !$a ){
   					break;
   				}
   
   				$m->parensInOp = true;
   				$a->parensInOp = true;
   				$return = $this->NewObj3('Less_Tree_Operation',array($op, array($return, $a), $isSpaced));
   			}
   		}
   
   		return $return;
   	}
   
   
   	/**
   	 * Parses the conditions
   	 *
   	 * @return Less_Tree_Condition|null
   	 */
   	private function parseConditions() {
   		$index = $this->pos;
   		$return = $a = $this->parseCondition();
   		if( $a ){
   			while( true ){
   				if( !$this->PeekReg('/\\G,\s*(not\s*)?\(/') ||  !$this->MatchChar(',') ){
   					break;
   				}
   				$b = $this->parseCondition();
   				if( !$b ){
   					break;
   				}
   
   				$return = $this->NewObj4('Less_Tree_Condition',array('or', $return, $b, $index));
   			}
   			return $return;
   		}
   	}
   
   	private function parseCondition() {
   		$index = $this->pos;
   		$negate = false;
   		$c = null;
   
   		if ($this->MatchReg('/\\Gnot/')) $negate = true;
   		$this->expectChar('(');
   		$a = $this->MatchFuncs(array('parseAddition','parseEntitiesKeyword','parseEntitiesQuoted'));
   
   		if( $a ){
   			$op = $this->MatchReg('/\\G(?:>=|<=|=<|[<=>])/');
   			if( $op ){
   				$b = $this->MatchFuncs(array('parseAddition','parseEntitiesKeyword','parseEntitiesQuoted'));
   				if( $b ){
   					$c = $this->NewObj5('Less_Tree_Condition',array($op[0], $a, $b, $index, $negate));
   				} else {
   					$this->Error('Unexpected expression');
   				}
   			} else {
   				$k = $this->NewObj1('Less_Tree_Keyword','true');
   				$c = $this->NewObj5('Less_Tree_Condition',array('=', $a, $k, $index, $negate));
   			}
   			$this->expectChar(')');
   			return $this->MatchReg('/\\Gand/') ? $this->NewObj3('Less_Tree_Condition',array('and', $c, $this->parseCondition())) : $c;
   		}
   	}
   
   	/**
   	 * An operand is anything that can be part of an operation,
   	 * such as a Color, or a Variable
   	 *
   	 */
   	private function parseOperand (){
   
   		$negate = false;
   		$offset = $this->pos+1;
   		if( $offset >= $this->input_len ){
   			return;
   		}
   		$char = $this->input[$offset];
   		if( $char === '@' || $char === '(' ){
   			$negate = $this->MatchChar('-');
   		}
   
   		$o = $this->MatchFuncs(array('parseSub','parseEntitiesDimension','parseEntitiesColor','parseEntitiesVariable','parseEntitiesCall'));
   
   		if( $negate ){
   			$o->parensInOp = true;
   			$o = $this->NewObj1('Less_Tree_Negative',$o);
   		}
   
   		return $o;
   	}
   
   
   	/**
   	 * Expressions either represent mathematical operations,
   	 * or white-space delimited Entities.
   	 *
   	 *	 1px solid black
   	 *	 @var * 2
   	 *
   	 * @return Less_Tree_Expression|null
   	 */
   	private function parseExpression (){
   		$entities = array();
   
   		do{
   			$e = $this->MatchFuncs(array('parseAddition','parseEntity'));
   			if( $e ){
   				$entities[] = $e;
   				// operations do not allow keyword "/" dimension (e.g. small/20px) so we support that here
   				if( !$this->PeekReg('/\\G\/[\/*]/') ){
   					$delim = $this->MatchChar('/');
   					if( $delim ){
   						$entities[] = $this->NewObj1('Less_Tree_Anonymous',$delim);
   					}
   				}
   			}
   		}while($e);
   
   		if( $entities ){
   			return $this->NewObj1('Less_Tree_Expression',$entities);
   		}
   	}
   
   
   	/**
   	 * Parse a property
   	 * eg: 'min-width', 'orientation', etc
   	 *
   	 * @return string
   	 */
   	private function parseProperty (){
   		$name = $this->MatchReg('/\\G(\*?-?[_a-zA-Z0-9-]+)\s*:/');
   		if( $name ){
   			return $name[1];
   		}
   	}
   
   
   	/**
   	 * Parse a rule property
   	 * eg: 'color', 'width', 'height', etc
   	 *
   	 * @return string
   	 */
   	private function parseRuleProperty(){
   		$offset = $this->pos;
   		$name = array();
   		$index = array();
   		$length = 0;
   
   
   		$this->rulePropertyMatch('/\\G(\*?)/', $offset, $length, $index, $name );
   		while( $this->rulePropertyMatch('/\\G((?:[\w-]+)|(?:@\{[\w-]+\}))/', $offset, $length, $index, $name )); // !
   
   		if( (count($name) > 1) && $this->rulePropertyMatch('/\\G\s*((?:\+_|\+)?)\s*:/', $offset, $length, $index, $name) ){
   			// at last, we have the complete match now. move forward,
   			// convert name particles to tree objects and return:
   			$this->skipWhitespace($length);
   
   			if( $name[0] === '' ){
   				array_shift($name);
   				array_shift($index);
   			}
   			foreach($name as $k => $s ){
   				if( !$s || $s[0] !== '@' ){
   					$name[$k] = $this->NewObj1('Less_Tree_Keyword',$s);
   				}else{
   					$name[$k] = $this->NewObj3('Less_Tree_Variable',array('@' . substr($s,2,-1), $index[$k], $this->env->currentFileInfo));
   				}
   			}
   			return $name;
   		}
   
   
   	}
   
   	private function rulePropertyMatch( $re, &$offset, &$length,  &$index, &$name ){
   		preg_match($re, $this->input, $a, 0, $offset);
   		if( $a ){
   			$index[] = $this->pos + $length;
   			$length += strlen($a[0]);
   			$offset += strlen($a[0]);
   			$name[] = $a[1];
   			return true;
   		}
   	}
   
   	public static function serializeVars( $vars ){
   		$s = '';
   
   		foreach($vars as $name => $value){
   			$s .= (($name[0] === '@') ? '' : '@') . $name .': '. $value . ((substr($value,-1) === ';') ? '' : ';');
   		}
   
   		return $s;
   	}
   
   
   	/**
   	 * Some versions of php have trouble with method_exists($a,$b) if $a is not an object
   	 *
   	 * @param string $b
   	 */
   	public static function is_method($a,$b){
   		return is_object($a) && method_exists($a,$b);
   	}
   
   
   	/**
   	 * Round numbers similarly to javascript
   	 * eg: 1.499999 to 1 instead of 2
   	 *
   	 */
   	public static function round($i, $precision = 0){
   
   		$precision = pow(10,$precision);
   		$i = $i*$precision;
   
   		$ceil = ceil($i);
   		$floor = floor($i);
   		if( ($ceil - $i) <= ($i - $floor) ){
   			return $ceil/$precision;
   		}else{
   			return $floor/$precision;
   		}
   	}
   
   
   	/**
   	 * Create Less_Tree_* objects and optionally generate a cache string
   	 *
   	 * @return mixed
   	 */
   	public function NewObj0($class){
   		$obj = new $class();
   		if( $this->CacheEnabled() ){
   			$obj->cache_string = ' new '.$class.'()';
   		}
   		return $obj;
   	}
   
   	public function NewObj1($class, $arg){
   		$obj = new $class( $arg );
   		if( $this->CacheEnabled() ){
   			$obj->cache_string = ' new '.$class.'('.Less_Parser::ArgString($arg).')';
   		}
   		return $obj;
   	}
   
   	public function NewObj2($class, $args){
   		$obj = new $class( $args[0], $args[1] );
   		if( $this->CacheEnabled() ){
   			$this->ObjCache( $obj, $class, $args);
   		}
   		return $obj;
   	}
   
   	public function NewObj3($class, $args){
   		$obj = new $class( $args[0], $args[1], $args[2] );
   		if( $this->CacheEnabled() ){
   			$this->ObjCache( $obj, $class, $args);
   		}
   		return $obj;
   	}
   
   	public function NewObj4($class, $args){
   		$obj = new $class( $args[0], $args[1], $args[2], $args[3] );
   		if( $this->CacheEnabled() ){
   			$this->ObjCache( $obj, $class, $args);
   		}
   		return $obj;
   	}
   
   	public function NewObj5($class, $args){
   		$obj = new $class( $args[0], $args[1], $args[2], $args[3], $args[4] );
   		if( $this->CacheEnabled() ){
   			$this->ObjCache( $obj, $class, $args);
   		}
   		return $obj;
   	}
   
   	public function NewObj6($class, $args){
   		$obj = new $class( $args[0], $args[1], $args[2], $args[3], $args[4], $args[5] );
   		if( $this->CacheEnabled() ){
   			$this->ObjCache( $obj, $class, $args);
   		}
   		return $obj;
   	}
   
   	public function NewObj7($class, $args){
   		$obj = new $class( $args[0], $args[1], $args[2], $args[3], $args[4], $args[5], $args[6] );
   		if( $this->CacheEnabled() ){
   			$this->ObjCache( $obj, $class, $args);
   		}
   		return $obj;
   	}
   
   	//caching
   	public function ObjCache($obj, $class, $args=array()){
   		$obj->cache_string = ' new '.$class.'('. self::ArgCache($args).')';
   	}
   
   	public function ArgCache($args){
   		return implode(',',array_map( array('Less_Parser','ArgString'),$args));
   	}
   
   
   	/**
   	 * Convert an argument to a string for use in the parser cache
   	 *
   	 * @return string
   	 */
   	public static function ArgString($arg){
   
   		$type = gettype($arg);
   
   		if( $type === 'object'){
   			$string = $arg->cache_string;
   			unset($arg->cache_string);
   			return $string;
   
   		}elseif( $type === 'array' ){
   			$string = ' Array(';
   			foreach($arg as $k => $a){
   				$string .= var_export($k,true).' => '.self::ArgString($a).',';
   			}
   			return $string . ')';
   		}
   
   		return var_export($arg,true);
   	}
   
   	public function Error($msg){
   		throw new Less_Exception_Parser($msg, null, $this->furthest, $this->env->currentFileInfo);
   	}
   
   	public static function WinPath($path){
   		return str_replace('\\', '/', $path);
   	}
   
   	public function CacheEnabled(){
   	    return false;
   		//return (Less_Parser::$options['cache_method'] && (Less_Cache::$cache_dir || (Less_Parser::$options['cache_method'] == 'callback')));
   	}
   
   }
    
   
   /**
    * Utility for css colors
    *
    * @package Less
    * @subpackage color
    */
   class Less_Colors {
   
   	public static $colors = array(
   			'aliceblue'=>'#f0f8ff',
   			'antiquewhite'=>'#faebd7',
   			'aqua'=>'#00ffff',
   			'aquamarine'=>'#7fffd4',
   			'azure'=>'#f0ffff',
   			'beige'=>'#f5f5dc',
   			'bisque'=>'#ffe4c4',
   			'black'=>'#000000',
   			'blanchedalmond'=>'#ffebcd',
   			'blue'=>'#0000ff',
   			'blueviolet'=>'#8a2be2',
   			'brown'=>'#a52a2a',
   			'burlywood'=>'#deb887',
   			'cadetblue'=>'#5f9ea0',
   			'chartreuse'=>'#7fff00',
   			'chocolate'=>'#d2691e',
   			'coral'=>'#ff7f50',
   			'cornflowerblue'=>'#6495ed',
   			'cornsilk'=>'#fff8dc',
   			'crimson'=>'#dc143c',
   			'cyan'=>'#00ffff',
   			'darkblue'=>'#00008b',
   			'darkcyan'=>'#008b8b',
   			'darkgoldenrod'=>'#b8860b',
   			'darkgray'=>'#a9a9a9',
   			'darkgrey'=>'#a9a9a9',
   			'darkgreen'=>'#006400',
   			'darkkhaki'=>'#bdb76b',
   			'darkmagenta'=>'#8b008b',
   			'darkolivegreen'=>'#556b2f',
   			'darkorange'=>'#ff8c00',
   			'darkorchid'=>'#9932cc',
   			'darkred'=>'#8b0000',
   			'darksalmon'=>'#e9967a',
   			'darkseagreen'=>'#8fbc8f',
   			'darkslateblue'=>'#483d8b',
   			'darkslategray'=>'#2f4f4f',
   			'darkslategrey'=>'#2f4f4f',
   			'darkturquoise'=>'#00ced1',
   			'darkviolet'=>'#9400d3',
   			'deeppink'=>'#ff1493',
   			'deepskyblue'=>'#00bfff',
   			'dimgray'=>'#696969',
   			'dimgrey'=>'#696969',
   			'dodgerblue'=>'#1e90ff',
   			'firebrick'=>'#b22222',
   			'floralwhite'=>'#fffaf0',
   			'forestgreen'=>'#228b22',
   			'fuchsia'=>'#ff00ff',
   			'gainsboro'=>'#dcdcdc',
   			'ghostwhite'=>'#f8f8ff',
   			'gold'=>'#ffd700',
   			'goldenrod'=>'#daa520',
   			'gray'=>'#808080',
   			'grey'=>'#808080',
   			'green'=>'#008000',
   			'greenyellow'=>'#adff2f',
   			'honeydew'=>'#f0fff0',
   			'hotpink'=>'#ff69b4',
   			'indianred'=>'#cd5c5c',
   			'indigo'=>'#4b0082',
   			'ivory'=>'#fffff0',
   			'khaki'=>'#f0e68c',
   			'lavender'=>'#e6e6fa',
   			'lavenderblush'=>'#fff0f5',
   			'lawngreen'=>'#7cfc00',
   			'lemonchiffon'=>'#fffacd',
   			'lightblue'=>'#add8e6',
   			'lightcoral'=>'#f08080',
   			'lightcyan'=>'#e0ffff',
   			'lightgoldenrodyellow'=>'#fafad2',
   			'lightgray'=>'#d3d3d3',
   			'lightgrey'=>'#d3d3d3',
   			'lightgreen'=>'#90ee90',
   			'lightpink'=>'#ffb6c1',
   			'lightsalmon'=>'#ffa07a',
   			'lightseagreen'=>'#20b2aa',
   			'lightskyblue'=>'#87cefa',
   			'lightslategray'=>'#778899',
   			'lightslategrey'=>'#778899',
   			'lightsteelblue'=>'#b0c4de',
   			'lightyellow'=>'#ffffe0',
   			'lime'=>'#00ff00',
   			'limegreen'=>'#32cd32',
   			'linen'=>'#faf0e6',
   			'magenta'=>'#ff00ff',
   			'maroon'=>'#800000',
   			'mediumaquamarine'=>'#66cdaa',
   			'mediumblue'=>'#0000cd',
   			'mediumorchid'=>'#ba55d3',
   			'mediumpurple'=>'#9370d8',
   			'mediumseagreen'=>'#3cb371',
   			'mediumslateblue'=>'#7b68ee',
   			'mediumspringgreen'=>'#00fa9a',
   			'mediumturquoise'=>'#48d1cc',
   			'mediumvioletred'=>'#c71585',
   			'midnightblue'=>'#191970',
   			'mintcream'=>'#f5fffa',
   			'mistyrose'=>'#ffe4e1',
   			'moccasin'=>'#ffe4b5',
   			'navajowhite'=>'#ffdead',
   			'navy'=>'#000080',
   			'oldlace'=>'#fdf5e6',
   			'olive'=>'#808000',
   			'olivedrab'=>'#6b8e23',
   			'orange'=>'#ffa500',
   			'orangered'=>'#ff4500',
   			'orchid'=>'#da70d6',
   			'palegoldenrod'=>'#eee8aa',
   			'palegreen'=>'#98fb98',
   			'paleturquoise'=>'#afeeee',
   			'palevioletred'=>'#d87093',
   			'papayawhip'=>'#ffefd5',
   			'peachpuff'=>'#ffdab9',
   			'peru'=>'#cd853f',
   			'pink'=>'#ffc0cb',
   			'plum'=>'#dda0dd',
   			'powderblue'=>'#b0e0e6',
   			'purple'=>'#800080',
   			'red'=>'#ff0000',
   			'rosybrown'=>'#bc8f8f',
   			'royalblue'=>'#4169e1',
   			'saddlebrown'=>'#8b4513',
   			'salmon'=>'#fa8072',
   			'sandybrown'=>'#f4a460',
   			'seagreen'=>'#2e8b57',
   			'seashell'=>'#fff5ee',
   			'sienna'=>'#a0522d',
   			'silver'=>'#c0c0c0',
   			'skyblue'=>'#87ceeb',
   			'slateblue'=>'#6a5acd',
   			'slategray'=>'#708090',
   			'slategrey'=>'#708090',
   			'snow'=>'#fffafa',
   			'springgreen'=>'#00ff7f',
   			'steelblue'=>'#4682b4',
   			'tan'=>'#d2b48c',
   			'teal'=>'#008080',
   			'thistle'=>'#d8bfd8',
   			'tomato'=>'#ff6347',
   			'turquoise'=>'#40e0d0',
   			'violet'=>'#ee82ee',
   			'wheat'=>'#f5deb3',
   			'white'=>'#ffffff',
   			'whitesmoke'=>'#f5f5f5',
   			'yellow'=>'#ffff00',
   			'yellowgreen'=>'#9acd32'
   		);
   
   	public static function hasOwnProperty($color) {
   		return isset(self::$colors[$color]);
   	}
   
   
   	public static function color($color) {
   		return self::$colors[$color];
   	}
   
   }
    
   
   
   /**
    * Environment
    *
    * @package Less
    * @subpackage environment
    */
   class Less_Environment{
   
   	//public $paths = array();				// option - unmodified - paths to search for imports on
   	//public static $files = array();		// list of files that have been imported, used for import-once
   	//public $rootpath;						// option - rootpath to append to URL's
   	//public static $strictImports = null;	// option -
   	//public $insecure;						// option - whether to allow imports from insecure ssl hosts
   	//public $processImports;				// option - whether to process imports. if false then imports will not be imported
   	//public $javascriptEnabled;			// option - whether JavaScript is enabled. if undefined, defaults to true
   	//public $useFileCache;					// browser only - whether to use the per file session cache
   	public $currentFileInfo;				// information about the current file - for error reporting and importing and making urls relative etc.
   
   	public $importMultiple = false; 		// whether we are currently importing multiple copies
   
   
   	/**
   	 * @var array
   	 */
   	public $frames = array();
   
   	/**
   	 * @var array
   	 */
   	public $mediaBlocks = array();
   
   	/**
   	 * @var array
   	 */
   	public $mediaPath = array();
   
   	public static $parensStack = 0;
   
   	public static $tabLevel = 0;
   
   	public static $lastRule = false;
   
   	public static $_outputMap;
   
   	public static $mixin_stack = 0;
   
   	/**
   	 * @var array
   	 */
   	public $functions = array();
   
   
   	public function Init(){
   
   		self::$parensStack = 0;
   		self::$tabLevel = 0;
   		self::$lastRule = false;
   		self::$mixin_stack = 0;
   
   		if( Less_Parser::$options['compress'] ){
   
   			Less_Environment::$_outputMap = array(
   				','	=> ',',
   				': ' => ':',
   				''  => '',
   				' ' => ' ',
   				':' => ' :',
   				'+' => '+',
   				'~' => '~',
   				'>' => '>',
   				'|' => '|',
   		        '^' => '^',
   		        '^^' => '^^'
   			);
   
   		}else{
   
   			Less_Environment::$_outputMap = array(
   				','	=> ', ',
   				': ' => ': ',
   				''  => '',
   				' ' => ' ',
   				':' => ' :',
   				'+' => ' + ',
   				'~' => ' ~ ',
   				'>' => ' > ',
   				'|' => '|',
   		        '^' => ' ^ ',
   		        '^^' => ' ^^ '
   			);
   
   		}
   	}
   
   
   	public function copyEvalEnv($frames = array() ){
   		$new_env = new Less_Environment();
   		$new_env->frames = $frames;
   		return $new_env;
   	}
   
   
   	public static function isMathOn(){
   		return !Less_Parser::$options['strictMath'] || Less_Environment::$parensStack;
   	}
   
   	public static function isPathRelative($path){
   		return !preg_match('/^(?:[a-z-]+:|\/)/',$path);
   	}
   
   
   	/**
   	 * Canonicalize a path by resolving references to '/./', '/../'
   	 * Does not remove leading "../"
   	 * @param string path or url
   	 * @return string Canonicalized path
   	 *
   	 */
   	public static function normalizePath($path){
   
   		$segments = explode('/',$path);
   		$segments = array_reverse($segments);
   
   		$path = array();
   		$path_len = 0;
   
   		while( $segments ){
   			$segment = array_pop($segments);
   			switch( $segment ) {
   
   				case '.':
   				break;
   
   				case '..':
   					if( !$path_len || ( $path[$path_len-1] === '..') ){
   						$path[] = $segment;
   						$path_len++;
   					}else{
   						array_pop($path);
   						$path_len--;
   					}
   				break;
   
   				default:
   					$path[] = $segment;
   					$path_len++;
   				break;
   			}
   		}
   
   		return implode('/',$path);
   	}
   
   
   	public function unshiftFrame($frame){
   		array_unshift($this->frames, $frame);
   	}
   
   	public function shiftFrame(){
   		return array_shift($this->frames);
   	}
   
   }
    
   
   /**
    * Builtin functions
    *
    * @package Less
    * @subpackage function
    * @see http://lesscss.org/functions/
    */
   class Less_Functions{
   
   	public $env;
   	public $currentFileInfo;
   
   	function __construct($env, $currentFileInfo = null ){
   		$this->env = $env;
   		$this->currentFileInfo = $currentFileInfo;
   	}
   
   	/**
   	 * @param string $op
   	 */
   	public static function operate( $op, $a, $b ){
   		switch ($op) {
   			case '+': return $a + $b;
   			case '-': return $a - $b;
   			case '*': return $a * $b;
   			case '/': return $a / $b;
   		}
   	}
   
   	public static function clamp($val, $max = 1){
   		return min( max($val, 0), $max);
   	}
   
   	public static function fround( $value ){
   
   		if( $value === 0 ){
   			return $value;
   		}
   
   		if( Less_Parser::$options['numPrecision'] ){
   			$p = pow(10, Less_Parser::$options['numPrecision']);
   			return round( $value * $p) / $p;
   		}
   		return $value;
   	}
   
   	public static function number($n){
   
   		if ($n instanceof Less_Tree_Dimension) {
   			return floatval( $n->unit->is('%') ? $n->value / 100 : $n->value);
   		} else if (is_numeric($n)) {
   			return $n;
   		} else {
   			throw new Less_Exception_Compiler("color functions take numbers as parameters");
   		}
   	}
   
   	public static function scaled($n, $size = 255 ){
   		if( $n instanceof Less_Tree_Dimension && $n->unit->is('%') ){
   			return (float)$n->value * $size / 100;
   		} else {
   			return Less_Functions::number($n);
   		}
   	}
   
   	public function rgb ($r = null, $g = null, $b = null){
   		if (is_null($r) || is_null($g) || is_null($b)) {
   			throw new Less_Exception_Compiler("rgb expects three parameters");
   		}
   		return $this->rgba($r, $g, $b, 1.0);
   	}
   
   	public function rgba($r = null, $g = null, $b = null, $a = null){
   		$rgb = array($r, $g, $b);
   		$rgb = array_map(array('Less_Functions','scaled'),$rgb);
   
   		$a = self::number($a);
   		return new Less_Tree_Color($rgb, $a);
   	}
   
   	public function hsl($h, $s, $l){
   		return $this->hsla($h, $s, $l, 1.0);
   	}
   
   	public function hsla($h, $s, $l, $a){
   
   		$h = fmod(self::number($h), 360) / 360; // Classic % operator will change float to int
   		$s = self::clamp(self::number($s));
   		$l = self::clamp(self::number($l));
   		$a = self::clamp(self::number($a));
   
   		$m2 = $l <= 0.5 ? $l * ($s + 1) : $l + $s - $l * $s;
   
   		$m1 = $l * 2 - $m2;
   
   		return $this->rgba( self::hsla_hue($h + 1/3, $m1, $m2) * 255,
   							self::hsla_hue($h, $m1, $m2) * 255,
   							self::hsla_hue($h - 1/3, $m1, $m2) * 255,
   							$a);
   	}
   
   	/**
   	 * @param double $h
   	 */
   	public function hsla_hue($h, $m1, $m2){
   		$h = $h < 0 ? $h + 1 : ($h > 1 ? $h - 1 : $h);
   		if	  ($h * 6 < 1) return $m1 + ($m2 - $m1) * $h * 6;
   		else if ($h * 2 < 1) return $m2;
   		else if ($h * 3 < 2) return $m1 + ($m2 - $m1) * (2/3 - $h) * 6;
   		else				 return $m1;
   	}
   
   	public function hsv($h, $s, $v) {
   		return $this->hsva($h, $s, $v, 1.0);
   	}
   
   	/**
   	 * @param double $a
   	 */
   	public function hsva($h, $s, $v, $a) {
   		$h = ((Less_Functions::number($h) % 360) / 360 ) * 360;
   		$s = Less_Functions::number($s);
   		$v = Less_Functions::number($v);
   		$a = Less_Functions::number($a);
   
   		$i = floor(($h / 60) % 6);
   		$f = ($h / 60) - $i;
   
   		$vs = array( $v,
   				  $v * (1 - $s),
   				  $v * (1 - $f * $s),
   				  $v * (1 - (1 - $f) * $s));
   
   		$perm = array(array(0, 3, 1),
   					array(2, 0, 1),
   					array(1, 0, 3),
   					array(1, 2, 0),
   					array(3, 1, 0),
   					array(0, 1, 2));
   
   		return $this->rgba($vs[$perm[$i][0]] * 255,
   						 $vs[$perm[$i][1]] * 255,
   						 $vs[$perm[$i][2]] * 255,
   						 $a);
   	}
   
   	public function hue($color = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to hue must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$c = $color->toHSL();
   		return new Less_Tree_Dimension(Less_Parser::round($c['h']));
   	}
   
   	public function saturation($color = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to saturation must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$c = $color->toHSL();
   		return new Less_Tree_Dimension(Less_Parser::round($c['s'] * 100), '%');
   	}
   
   	public function lightness($color = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to lightness must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$c = $color->toHSL();
   		return new Less_Tree_Dimension(Less_Parser::round($c['l'] * 100), '%');
   	}
   
   	public function hsvhue( $color = null ){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to hsvhue must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsv = $color->toHSV();
   		return new Less_Tree_Dimension( Less_Parser::round($hsv['h']) );
   	}
   
   
   	public function hsvsaturation( $color = null ){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to hsvsaturation must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsv = $color->toHSV();
   		return new Less_Tree_Dimension( Less_Parser::round($hsv['s'] * 100), '%' );
   	}
   
   	public function hsvvalue( $color = null ){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to hsvvalue must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsv = $color->toHSV();
   		return new Less_Tree_Dimension( Less_Parser::round($hsv['v'] * 100), '%' );
   	}
   
   	public function red($color = null) {
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to red must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return new Less_Tree_Dimension( $color->rgb[0] );
   	}
   
   	public function green($color = null) {
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to green must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return new Less_Tree_Dimension( $color->rgb[1] );
   	}
   
   	public function blue($color = null) {
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to blue must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return new Less_Tree_Dimension( $color->rgb[2] );
   	}
   
   	public function alpha($color = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to alpha must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$c = $color->toHSL();
   		return new Less_Tree_Dimension($c['a']);
   	}
   
   	public function luma ($color = null) {
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to luma must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return new Less_Tree_Dimension(Less_Parser::round( $color->luma() * $color->alpha * 100), '%');
   	}
   
   	public function luminance( $color = null ){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to luminance must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$luminance =
   			(0.2126 * $color->rgb[0] / 255)
   		  + (0.7152 * $color->rgb[1] / 255)
   		  + (0.0722 * $color->rgb[2] / 255);
   
   		return new Less_Tree_Dimension(Less_Parser::round( $luminance * $color->alpha * 100), '%');
   	}
   
   	public function saturate($color = null, $amount = null){
   		// filter: saturate(3.2);
   		// should be kept as is, so check for color
   		if ($color instanceof Less_Tree_Dimension) {
   			return null;
   		}
   
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to saturate must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$amount instanceof Less_Tree_Dimension) {
   			throw new Less_Exception_Compiler('The second argument to saturate must be a percentage' . ($amount instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsl = $color->toHSL();
   
   		$hsl['s'] += $amount->value / 100;
   		$hsl['s'] = self::clamp($hsl['s']);
   
   		return $this->hsla($hsl['h'], $hsl['s'], $hsl['l'], $hsl['a']);
   	}
   
   	/**
   	 * @param Less_Tree_Dimension $amount
   	 */
   	public function desaturate($color = null, $amount = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to desaturate must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$amount instanceof Less_Tree_Dimension) {
   			throw new Less_Exception_Compiler('The second argument to desaturate must be a percentage' . ($amount instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsl = $color->toHSL();
   
   		$hsl['s'] -= $amount->value / 100;
   		$hsl['s'] = self::clamp($hsl['s']);
   
   		return $this->hsla($hsl['h'], $hsl['s'], $hsl['l'], $hsl['a']);
   	}
   
   
   
   	public function lighten($color = null, $amount=null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to lighten must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$amount instanceof Less_Tree_Dimension) {
   			throw new Less_Exception_Compiler('The second argument to lighten must be a percentage' . ($amount instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsl = $color->toHSL();
   
   		$hsl['l'] += $amount->value / 100;
   		$hsl['l'] = self::clamp($hsl['l']);
   
   		return $this->hsla($hsl['h'], $hsl['s'], $hsl['l'], $hsl['a']);
   	}
   
   	public function darken($color = null, $amount = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to darken must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$amount instanceof Less_Tree_Dimension) {
   			throw new Less_Exception_Compiler('The second argument to darken must be a percentage' . ($amount instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsl = $color->toHSL();
   		$hsl['l'] -= $amount->value / 100;
   		$hsl['l'] = self::clamp($hsl['l']);
   
   		return $this->hsla($hsl['h'], $hsl['s'], $hsl['l'], $hsl['a']);
   	}
   
   	public function fadein($color = null, $amount = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to fadein must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$amount instanceof Less_Tree_Dimension) {
   			throw new Less_Exception_Compiler('The second argument to fadein must be a percentage' . ($amount instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsl = $color->toHSL();
   		$hsl['a'] += $amount->value / 100;
   		$hsl['a'] = self::clamp($hsl['a']);
   		return $this->hsla($hsl['h'], $hsl['s'], $hsl['l'], $hsl['a']);
   	}
   
   	public function fadeout($color = null, $amount = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to fadeout must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$amount instanceof Less_Tree_Dimension) {
   			throw new Less_Exception_Compiler('The second argument to fadeout must be a percentage' . ($amount instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsl = $color->toHSL();
   		$hsl['a'] -= $amount->value / 100;
   		$hsl['a'] = self::clamp($hsl['a']);
   		return $this->hsla($hsl['h'], $hsl['s'], $hsl['l'], $hsl['a']);
   	}
   
   	public function fade($color = null, $amount = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to fade must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$amount instanceof Less_Tree_Dimension) {
   			throw new Less_Exception_Compiler('The second argument to fade must be a percentage' . ($amount instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsl = $color->toHSL();
   
   		$hsl['a'] = $amount->value / 100;
   		$hsl['a'] = self::clamp($hsl['a']);
   		return $this->hsla($hsl['h'], $hsl['s'], $hsl['l'], $hsl['a']);
   	}
   
   
   
   	public function spin($color = null, $amount = null){
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to spin must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$amount instanceof Less_Tree_Dimension) {
   			throw new Less_Exception_Compiler('The second argument to spin must be a number' . ($amount instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$hsl = $color->toHSL();
   		$hue = fmod($hsl['h'] + $amount->value, 360);
   
   		$hsl['h'] = $hue < 0 ? 360 + $hue : $hue;
   
   		return $this->hsla($hsl['h'], $hsl['s'], $hsl['l'], $hsl['a']);
   	}
   
   	//
   	// Copyright (c) 2006-2009 Hampton Catlin, Nathan Weizenbaum, and Chris Eppstein
   	// http://sass-lang.com
   	//
   
   	/**
   	 * @param Less_Tree_Color $color1
   	 */
   	public function mix($color1 = null, $color2 = null, $weight = null){
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to mix must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to mix must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$weight) {
   			$weight = new Less_Tree_Dimension('50', '%');
   		}
   		if (!$weight instanceof Less_Tree_Dimension) {
   			throw new Less_Exception_Compiler('The third argument to contrast must be a percentage' . ($weight instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		$p = $weight->value / 100.0;
   		$w = $p * 2 - 1;
   		$hsl1 = $color1->toHSL();
   		$hsl2 = $color2->toHSL();
   		$a = $hsl1['a'] - $hsl2['a'];
   
   		$w1 = (((($w * $a) == -1) ? $w : ($w + $a) / (1 + $w * $a)) + 1) / 2;
   		$w2 = 1 - $w1;
   
   		$rgb = array($color1->rgb[0] * $w1 + $color2->rgb[0] * $w2,
   					 $color1->rgb[1] * $w1 + $color2->rgb[1] * $w2,
   					 $color1->rgb[2] * $w1 + $color2->rgb[2] * $w2);
   
   		$alpha = $color1->alpha * $p + $color2->alpha * (1 - $p);
   
   		return new Less_Tree_Color($rgb, $alpha);
   	}
   
   	public function greyscale($color){
   		return $this->desaturate($color, new Less_Tree_Dimension(100,'%'));
   	}
   
   
   	public function contrast( $color, $dark = null, $light = null, $threshold = null){
   		// filter: contrast(3.2);
   		// should be kept as is, so check for color
   		if (!$color instanceof Less_Tree_Color) {
   			return null;
   		}
   		if( !$light ){
   			$light = $this->rgba(255, 255, 255, 1.0);
   		}
   		if( !$dark ){
   			$dark = $this->rgba(0, 0, 0, 1.0);
   		}
   
   		if (!$dark instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to contrast must be a color' . ($dark instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$light instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The third argument to contrast must be a color' . ($light instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		//Figure out which is actually light and dark!
   		if( $dark->luma() > $light->luma() ){
   			$t = $light;
   			$light = $dark;
   			$dark = $t;
   		}
   		if( !$threshold ){
   			$threshold = 0.43;
   		} else {
   			$threshold = Less_Functions::number($threshold);
   		}
   
   		if( $color->luma() < $threshold ){
   			return $light;
   		} else {
   			return $dark;
   		}
   	}
   
   	public function e ($str){
   		if( is_string($str) ){
   			return new Less_Tree_Anonymous($str);
   		}
   		return new Less_Tree_Anonymous($str instanceof Less_Tree_JavaScript ? $str->expression : $str->value);
   	}
   
   	public function escape ($str){
   
   		$revert = array('%21'=>'!', '%2A'=>'*', '%27'=>"'",'%3F'=>'?','%26'=>'&','%2C'=>',','%2F'=>'/','%40'=>'@','%2B'=>'+','%24'=>'$');
   
   		return new Less_Tree_Anonymous(strtr(rawurlencode($str->value), $revert));
   	}
   
   
   	/**
   	 * todo: This function will need some additional work to make it work the same as less.js
   	 *
   	 */
   	public function replace( $string, $pattern, $replacement, $flags = null ){
   		$result = $string->value;
   
   		$expr = '/'.str_replace('/','\\/',$pattern->value).'/';
   		if( $flags && $flags->value){
   			$expr .= self::replace_flags($flags->value);
   		}
   
   		$result = preg_replace($expr,$replacement->value,$result);
   
   
   		if( property_exists($string,'quote') ){
   			return new Less_Tree_Quoted( $string->quote, $result, $string->escaped);
   		}
   		return new Less_Tree_Quoted( '', $result );
   	}
   
   	public static function replace_flags($flags){
   		$flags = str_split($flags,1);
   		$new_flags = '';
   
   		foreach($flags as $flag){
   			switch($flag){
   				case 'e':
   				case 'g':
   				break;
   
   				default:
   				$new_flags .= $flag;
   				break;
   			}
   		}
   
   		return $new_flags;
   	}
   
   	public function _percent(){
   		$string = func_get_arg(0);
   
   		$args = func_get_args();
   		array_shift($args);
   		$result = $string->value;
   
   		foreach($args as $arg){
   			if( preg_match('/%[sda]/i',$result, $token) ){
   				$token = $token[0];
   				$value = stristr($token, 's') ? $arg->value : $arg->toCSS();
   				$value = preg_match('/[A-Z]$/', $token) ? urlencode($value) : $value;
   				$result = preg_replace('/%[sda]/i',$value, $result, 1);
   			}
   		}
   		$result = str_replace('%%', '%', $result);
   
   		return new Less_Tree_Quoted( $string->quote , $result, $string->escaped);
   	}
   
   	public function unit( $val, $unit = null) {
   		if( !($val instanceof Less_Tree_Dimension) ){
   			throw new Less_Exception_Compiler('The first argument to unit must be a number' . ($val instanceof Less_Tree_Operation ? '. Have you forgotten parenthesis?' : '.') );
   		}
   
   		if( $unit ){
   			if( $unit instanceof Less_Tree_Keyword ){
   				$unit = $unit->value;
   			} else {
   				$unit = $unit->toCSS();
   			}
   		} else {
   			$unit = "";
   		}
   		return new Less_Tree_Dimension($val->value, $unit );
   	}
   
   	public function convert($val, $unit){
   		return $val->convertTo($unit->value);
   	}
   
   	public function round($n, $f = false) {
   
   		$fraction = 0;
   		if( $f !== false ){
   			$fraction = $f->value;
   		}
   
   		return $this->_math('Less_Parser::round',null, $n, $fraction);
   	}
   
   	public function pi(){
   		return new Less_Tree_Dimension(M_PI);
   	}
   
   	public function mod($a, $b) {
   		return new Less_Tree_Dimension( $a->value % $b->value, $a->unit);
   	}
   
   
   
   	public function pow($x, $y) {
   		if( is_numeric($x) && is_numeric($y) ){
   			$x = new Less_Tree_Dimension($x);
   			$y = new Less_Tree_Dimension($y);
   		}elseif( !($x instanceof Less_Tree_Dimension) || !($y instanceof Less_Tree_Dimension) ){
   			throw new Less_Exception_Compiler('Arguments must be numbers');
   		}
   
   		return new Less_Tree_Dimension( pow($x->value, $y->value), $x->unit );
   	}
   
   	// var mathFunctions = [{name:"ce ...
   	public function ceil( $n ){		return $this->_math('ceil', null, $n); }
   	public function floor( $n ){	return $this->_math('floor', null, $n); }
   	public function sqrt( $n ){		return $this->_math('sqrt', null, $n); }
   	public function abs( $n ){		return $this->_math('abs', null, $n); }
   
   	public function tan( $n ){		return $this->_math('tan', '', $n);	}
   	public function sin( $n ){		return $this->_math('sin', '', $n);	}
   	public function cos( $n ){		return $this->_math('cos', '', $n);	}
   
   	public function atan( $n ){		return $this->_math('atan', 'rad', $n);	}
   	public function asin( $n ){		return $this->_math('asin', 'rad', $n);	}
   	public function acos( $n ){		return $this->_math('acos', 'rad', $n);	}
   
   	private function _math() {
   		$args = func_get_args();
   		$fn = array_shift($args);
   		$unit = array_shift($args);
   
   		if ($args[0] instanceof Less_Tree_Dimension) {
   
   			if( $unit === null ){
   				$unit = $args[0]->unit;
   			}else{
   				$args[0] = $args[0]->unify();
   			}
   			$args[0] = (float)$args[0]->value;
   			return new Less_Tree_Dimension( call_user_func_array($fn, $args), $unit);
   		} else if (is_numeric($args[0])) {
   			return call_user_func_array($fn,$args);
   		} else {
   			throw new Less_Exception_Compiler("math functions take numbers as parameters");
   		}
   	}
   
   	/**
   	 * @param boolean $isMin
   	 */
   	private function _minmax( $isMin, $args ){
   
   		$arg_count = count($args);
   
   		if( $arg_count < 1 ){
   			throw new Less_Exception_Compiler( 'one or more arguments required');
   		}
   
   		$j = null;
   		$unitClone = null;
   		$unitStatic = null;
   
   
   		$order = array();	// elems only contains original argument values.
   		$values = array();	// key is the unit.toString() for unified tree.Dimension values,
   							// value is the index into the order array.
   
   
   		for( $i = 0; $i < $arg_count; $i++ ){
   			$current = $args[$i];
   			if( !($current instanceof Less_Tree_Dimension) ){
   				if( is_array($args[$i]->value) ){
   					$args[] = $args[$i]->value;
   				}
   				continue;
   			}
   
   			if( $current->unit->toString() === '' && !$unitClone ){
   				$temp = new Less_Tree_Dimension($current->value, $unitClone);
   				$currentUnified = $temp->unify();
   			}else{
   				$currentUnified = $current->unify();
   			}
   
   			if( $currentUnified->unit->toString() === "" && !$unitStatic ){
   				$unit = $unitStatic;
   			}else{
   				$unit = $currentUnified->unit->toString();
   			}
   
   			if( $unit !== '' && !$unitStatic || $unit !== '' && $order[0]->unify()->unit->toString() === "" ){
   				$unitStatic = $unit;
   			}
   
   			if( $unit != '' && !$unitClone ){
   				$unitClone = $current->unit->toString();
   			}
   
   			if( isset($values['']) && $unit !== '' && $unit === $unitStatic ){
   				$j = $values[''];
   			}elseif( isset($values[$unit]) ){
   				$j = $values[$unit];
   			}else{
   
   				if( $unitStatic && $unit !== $unitStatic ){
   					throw new Less_Exception_Compiler( 'incompatible types');
   				}
   				$values[$unit] = count($order);
   				$order[] = $current;
   				continue;
   			}
   
   
   			if( $order[$j]->unit->toString() === "" && $unitClone ){
   				$temp = new Less_Tree_Dimension( $order[$j]->value, $unitClone);
   				$referenceUnified = $temp->unify();
   			}else{
   				$referenceUnified = $order[$j]->unify();
   			}
   			if( ($isMin && $currentUnified->value < $referenceUnified->value) || (!$isMin && $currentUnified->value > $referenceUnified->value) ){
   				$order[$j] = $current;
   			}
   		}
   
   		if( count($order) == 1 ){
   			return $order[0];
   		}
   		$args = array();
   		foreach($order as $a){
   			$args[] = $a->toCSS($this->env);
   		}
   		return new Less_Tree_Anonymous( ($isMin?'min(':'max(') . implode(Less_Environment::$_outputMap[','],$args).')');
   	}
   
   	public function min(){
   		$args = func_get_args();
   		return $this->_minmax( true, $args );
   	}
   
   	public function max(){
   		$args = func_get_args();
   		return $this->_minmax( false, $args );
   	}
   
   	public function getunit($n){
   		return new Less_Tree_Anonymous($n->unit);
   	}
   
   	public function argb($color) {
   		if (!$color instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to argb must be a color' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return new Less_Tree_Anonymous($color->toARGB());
   	}
   
   	public function percentage($n) {
   		return new Less_Tree_Dimension($n->value * 100, '%');
   	}
   
   	public function color($n) {
   
   		if( $n instanceof Less_Tree_Quoted ){
   			$colorCandidate = $n->value;
   			$returnColor = Less_Tree_Color::fromKeyword($colorCandidate);
   			if( $returnColor ){
   				return $returnColor;
   			}
   			if( preg_match('/^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})/',$colorCandidate) ){
   				return new Less_Tree_Color(substr($colorCandidate, 1));
   			}
   			throw new Less_Exception_Compiler("argument must be a color keyword or 3/6 digit hex e.g. #FFF");
   		} else {
   			throw new Less_Exception_Compiler("argument must be a string");
   		}
   	}
   
   
   	public function iscolor($n) {
   		return $this->_isa($n, 'Less_Tree_Color');
   	}
   
   	public function isnumber($n) {
   		return $this->_isa($n, 'Less_Tree_Dimension');
   	}
   
   	public function isstring($n) {
   		return $this->_isa($n, 'Less_Tree_Quoted');
   	}
   
   	public function iskeyword($n) {
   		return $this->_isa($n, 'Less_Tree_Keyword');
   	}
   
   	public function isurl($n) {
   		return $this->_isa($n, 'Less_Tree_Url');
   	}
   
   	public function ispixel($n) {
   		return $this->isunit($n, 'px');
   	}
   
   	public function ispercentage($n) {
   		return $this->isunit($n, '%');
   	}
   
   	public function isem($n) {
   		return $this->isunit($n, 'em');
   	}
   
   	/**
   	 * @param string $unit
   	 */
   	public function isunit( $n, $unit ){
   		return ($n instanceof Less_Tree_Dimension) && $n->unit->is( ( property_exists($unit,'value') ? $unit->value : $unit) ) ? new Less_Tree_Keyword('true') : new Less_Tree_Keyword('false');
   	}
   
   	/**
   	 * @param string $type
   	 */
   	private function _isa($n, $type) {
   		return is_a($n, $type) ? new Less_Tree_Keyword('true') : new Less_Tree_Keyword('false');
   	}
   
   	public function tint($color, $amount) {
   		return $this->mix( $this->rgb(255,255,255), $color, $amount);
   	}
   
   	public function shade($color, $amount) {
   		return $this->mix($this->rgb(0, 0, 0), $color, $amount);
   	}
   
   	public function extract($values, $index ){
   		$index = (int)$index->value - 1; // (1-based index)
   		// handle non-array values as an array of length 1
   		// return 'undefined' if index is invalid
   		if( property_exists($values,'value') && is_array($values->value) ){
   			if( isset($values->value[$index]) ){
   				return $values->value[$index];
   			}
   			return null;
   
   		}elseif( (int)$index === 0 ){
   			return $values;
   		}
   
   		return null;
   	}
   
   	public function length($values){
   		$n = (property_exists($values,'value') && is_array($values->value)) ? count($values->value) : 1;
   		return new Less_Tree_Dimension($n);
   	}
   
   	public function datauri($mimetypeNode, $filePathNode = null ) {
   
   		$filePath = ( $filePathNode ? $filePathNode->value : null );
   		$mimetype = $mimetypeNode->value;
   
   		$args = 2;
   		if( !$filePath ){
   			$filePath = $mimetype;
   			$args = 1;
   		}
   
   		$filePath = str_replace('\\','/',$filePath);
   		if( Less_Environment::isPathRelative($filePath) ){
   
   			if( Less_Parser::$options['relativeUrls'] ){
   				$temp = $this->currentFileInfo['currentDirectory'];
   			} else {
   				$temp = $this->currentFileInfo['entryPath'];
   			}
   
   			if( !empty($temp) ){
   				$filePath = Less_Environment::normalizePath(rtrim($temp,'/').'/'.$filePath);
   			}
   
   		}
   
   
   		// detect the mimetype if not given
   		if( $args < 2 ){
   
   			/* incomplete
   			$mime = require('mime');
   			mimetype = mime.lookup(path);
   
   			// use base 64 unless it's an ASCII or UTF-8 format
   			var charset = mime.charsets.lookup(mimetype);
   			useBase64 = ['US-ASCII', 'UTF-8'].indexOf(charset) < 0;
   			if (useBase64) mimetype += ';base64';
   			*/
   
   			$mimetype = Less_Mime::lookup($filePath);
   
   			$charset = Less_Mime::charsets_lookup($mimetype);
   			$useBase64 = !in_array($charset,array('US-ASCII', 'UTF-8'));
   			if( $useBase64 ){ $mimetype .= ';base64'; }
   
   		}else{
   			$useBase64 = preg_match('/;base64$/',$mimetype);
   		}
   
   
   		if( file_exists($filePath) ){
   			$buf = @file_get_contents($filePath);
   		}else{
   			$buf = false;
   		}
   
   
   		// IE8 cannot handle a data-uri larger than 32KB. If this is exceeded
   		// and the --ieCompat flag is enabled, return a normal url() instead.
   		$DATA_URI_MAX_KB = 32;
   		$fileSizeInKB = round( strlen($buf) / 1024 );
   		if( $fileSizeInKB >= $DATA_URI_MAX_KB ){
   			$url = new Less_Tree_Url( ($filePathNode ? $filePathNode : $mimetypeNode), $this->currentFileInfo);
   			return $url->compile($this);
   		}
   
   		if( $buf ){
   			$buf = $useBase64 ? base64_encode($buf) : rawurlencode($buf);
   			$filePath = '"data:' . $mimetype . ',' . $buf . '"';
   		}
   
   		return new Less_Tree_Url( new Less_Tree_Anonymous($filePath) );
   	}
   
   	//svg-gradient
   	public function svggradient( $direction ){
   
   		$throw_message = 'svg-gradient expects direction, start_color [start_position], [color position,]..., end_color [end_position]';
   		$arguments = func_get_args();
   
   		if( count($arguments) < 3 ){
   			throw new Less_Exception_Compiler( $throw_message );
   		}
   
   		$stops = array_slice($arguments,1);
   		$gradientType = 'linear';
   		$rectangleDimension = 'x="0" y="0" width="1" height="1"';
   		$useBase64 = true;
   		$directionValue = $direction->toCSS();
   
   
   		switch( $directionValue ){
   			case "to bottom":
   				$gradientDirectionSvg = 'x1="0%" y1="0%" x2="0%" y2="100%"';
   				break;
   			case "to right":
   				$gradientDirectionSvg = 'x1="0%" y1="0%" x2="100%" y2="0%"';
   				break;
   			case "to bottom right":
   				$gradientDirectionSvg = 'x1="0%" y1="0%" x2="100%" y2="100%"';
   				break;
   			case "to top right":
   				$gradientDirectionSvg = 'x1="0%" y1="100%" x2="100%" y2="0%"';
   				break;
   			case "ellipse":
   			case "ellipse at center":
   				$gradientType = "radial";
   				$gradientDirectionSvg = 'cx="50%" cy="50%" r="75%"';
   				$rectangleDimension = 'x="-50" y="-50" width="101" height="101"';
   				break;
   			default:
   				throw new Less_Exception_Compiler( "svg-gradient direction must be 'to bottom', 'to right', 'to bottom right', 'to top right' or 'ellipse at center'" );
   		}
   
   		$returner = '<?xml version="1.0" ?>' .
   			'<svg xmlns="http://www.w3.org/2000/svg" version="1.1" width="100%" height="100%" viewBox="0 0 1 1" preserveAspectRatio="none">' .
   			'<' . $gradientType . 'Gradient id="gradient" gradientUnits="userSpaceOnUse" ' . $gradientDirectionSvg . '>';
   
   		for( $i = 0; $i < count($stops); $i++ ){
   			if( is_object($stops[$i]) && property_exists($stops[$i],'value') ){
   				$color = $stops[$i]->value[0];
   				$position = $stops[$i]->value[1];
   			}else{
   				$color = $stops[$i];
   				$position = null;
   			}
   
   			if( !($color instanceof Less_Tree_Color) || (!(($i === 0 || $i+1 === count($stops)) && $position === null) && !($position instanceof Less_Tree_Dimension)) ){
   				throw new Less_Exception_Compiler( $throw_message );
   			}
   			if( $position ){
   				$positionValue = $position->toCSS();
   			}elseif( $i === 0 ){
   				$positionValue = '0%';
   			}else{
   				$positionValue = '100%';
   			}
   			$alpha = $color->alpha;
   			$returner .= '<stop offset="' . $positionValue . '" stop-color="' . $color->toRGB() . '"' . ($alpha < 1 ? ' stop-opacity="' . $alpha . '"' : '') . '/>';
   		}
   
   		$returner .= '</' . $gradientType . 'Gradient><rect ' . $rectangleDimension . ' fill="url(#gradient)" /></svg>';
   
   
   		if( $useBase64 ){
   			$returner = "'data:image/svg+xml;base64,".base64_encode($returner)."'";
   		}else{
   			$returner = "'data:image/svg+xml,".$returner."'";
   		}
   
   		return new Less_Tree_URL( new Less_Tree_Anonymous( $returner ) );
   	}
   
   
   	/**
   	 * Php version of javascript's `encodeURIComponent` function
   	 *
   	 * @param string $string The string to encode
   	 * @return string The encoded string
   	 */
   	public static function encodeURIComponent($string){
   		$revert = array('%21' => '!', '%2A' => '*', '%27' => "'", '%28' => '(', '%29' => ')');
   		return strtr(rawurlencode($string), $revert);
   	}
   
   
   	// Color Blending
   	// ref: http://www.w3.org/TR/compositing-1
   
   	public function colorBlend( $mode, $color1, $color2 ){
   		$ab = $color1->alpha;	// backdrop
   		$as = $color2->alpha;	// source
   		$r = array();			// result
   
   		$ar = $as + $ab * (1 - $as);
   		for( $i = 0; $i < 3; $i++ ){
   			$cb = $color1->rgb[$i] / 255;
   			$cs = $color2->rgb[$i] / 255;
   			$cr = call_user_func( $mode, $cb, $cs );
   			if( $ar ){
   				$cr = ($as * $cs + $ab * ($cb - $as * ($cb + $cs - $cr))) / $ar;
   			}
   			$r[$i] = $cr * 255;
   		}
   
   		return new Less_Tree_Color($r, $ar);
   	}
   
   	public function multiply($color1 = null, $color2 = null ){
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to multiply must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to multiply must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return $this->colorBlend( array($this,'colorBlendMultiply'),  $color1, $color2 );
   	}
   
   	private function colorBlendMultiply($cb, $cs){
   		return $cb * $cs;
   	}
   
   	public function screen($color1 = null, $color2 = null ){
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to screen must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to screen must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return $this->colorBlend( array($this,'colorBlendScreen'),  $color1, $color2 );
   	}
   
   	private function colorBlendScreen( $cb, $cs){
   		return $cb + $cs - $cb * $cs;
   	}
   
   	public function overlay($color1 = null, $color2 = null){
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to overlay must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to overlay must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return $this->colorBlend( array($this,'colorBlendOverlay'),  $color1, $color2 );
   	}
   
   	private function colorBlendOverlay($cb, $cs ){
   		$cb *= 2;
   		return ($cb <= 1)
   			? $this->colorBlendMultiply($cb, $cs)
   			: $this->colorBlendScreen($cb - 1, $cs);
   	}
   
   	public function softlight($color1 = null, $color2 = null){
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to softlight must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to softlight must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return $this->colorBlend( array($this,'colorBlendSoftlight'),  $color1, $color2 );
   	}
   
   	private function colorBlendSoftlight($cb, $cs ){
   		$d = 1;
   		$e = $cb;
   		if( $cs > 0.5 ){
   			$e = 1;
   			$d = ($cb > 0.25) ? sqrt($cb)
   				: ((16 * $cb - 12) * $cb + 4) * $cb;
   		}
   		return $cb - (1 - 2 * $cs) * $e * ($d - $cb);
   	}
   
   	public function hardlight($color1 = null, $color2 = null){
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to hardlight must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to hardlight must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return $this->colorBlend( array($this,'colorBlendHardlight'),  $color1, $color2 );
   	}
   
   	private function colorBlendHardlight( $cb, $cs ){
   		return $this->colorBlendOverlay($cs, $cb);
   	}
   
   	public function difference($color1 = null, $color2 = null) {
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to difference must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to difference must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return $this->colorBlend( array($this,'colorBlendDifference'),  $color1, $color2 );
   	}
   
   	private function colorBlendDifference( $cb, $cs ){
   		return abs($cb - $cs);
   	}
   
   	public function exclusion( $color1 = null, $color2 = null ){
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to exclusion must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to exclusion must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return $this->colorBlend( array($this,'colorBlendExclusion'),  $color1, $color2 );
   	}
   
   	private function colorBlendExclusion( $cb, $cs ){
   		return $cb + $cs - 2 * $cb * $cs;
   	}
   
   	public function average($color1 = null, $color2 = null){
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to average must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to average must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return $this->colorBlend( array($this,'colorBlendAverage'),  $color1, $color2 );
   	}
   
   	// non-w3c functions:
   	public function colorBlendAverage($cb, $cs ){
   		return ($cb + $cs) / 2;
   	}
   
   	public function negation($color1 = null, $color2 = null ){
   		if (!$color1 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The first argument to negation must be a color' . ($color1 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   		if (!$color2 instanceof Less_Tree_Color) {
   			throw new Less_Exception_Compiler('The second argument to negation must be a color' . ($color2 instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
   		}
   
   		return $this->colorBlend( array($this,'colorBlendNegation'),  $color1, $color2 );
   	}
   
   	public function colorBlendNegation($cb, $cs){
   		return 1 - abs($cb + $cs - 1);
   	}
   
   	// ~ End of Color Blending
   
   }
    
   
   /**
    * Mime lookup
    *
    * @package Less
    * @subpackage node
    */
   class Less_Mime{
   
   	// this map is intentionally incomplete
   	// if you want more, install 'mime' dep
   	static $_types = array(
   	        '.htm' => 'text/html',
   	        '.html'=> 'text/html',
   	        '.gif' => 'image/gif',
   	        '.jpg' => 'image/jpeg',
   	        '.jpeg'=> 'image/jpeg',
   	        '.png' => 'image/png',
   	        '.ttf' => 'application/x-font-ttf',
   	        '.otf' => 'application/x-font-otf',
   	        '.eot' => 'application/vnd.ms-fontobject',
   	        '.woff' => 'application/x-font-woff',
   	        '.svg' => 'image/svg+xml',
   	        );
   
   	public static function lookup( $filepath ){
   		$parts = explode('.',$filepath);
   		$ext = '.'.strtolower(array_pop($parts));
   
   		if( !isset(self::$_types[$ext]) ){
   			return null;
   		}
   		return self::$_types[$ext];
   	}
   
   	public static function charsets_lookup( $type = null ){
   		// assumes all text types are UTF-8
   		return $type && preg_match('/^text\//',$type) ? 'UTF-8' : '';
   	}
   }
    
   
   /**
    * Tree
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree{
   
   	public $cache_string;
   
   	public function toCSS(){
   		$output = new Less_Output();
   		$this->genCSS($output);
   		return $output->toString();
   	}
   
   
       /**
        * Generate CSS by adding it to the output object
        *
        * @param Less_Output $output The output
        * @return void
        */
       public function genCSS($output){}
   
   
   	/**
   	 * @param Less_Tree_Ruleset[] $rules
   	 */
   	public static function outputRuleset( $output, $rules ){
   
   		$ruleCnt = count($rules);
   		Less_Environment::$tabLevel++;
   
   
   		// Compressed
   		if( Less_Parser::$options['compress'] ){
   			$output->add('{');
   			for( $i = 0; $i < $ruleCnt; $i++ ){
   				$rules[$i]->genCSS( $output );
   			}
   
   			$output->add( '}' );
   			Less_Environment::$tabLevel--;
   			return;
   		}
   
   
   		// Non-compressed
   		$tabSetStr = "\n".str_repeat( Less_Parser::$options['indentation'] , Less_Environment::$tabLevel-1 );
   		$tabRuleStr = $tabSetStr.Less_Parser::$options['indentation'];
   
   		$output->add( " {" );
   		for($i = 0; $i < $ruleCnt; $i++ ){
   			$output->add( $tabRuleStr );
   			$rules[$i]->genCSS( $output );
   		}
   		Less_Environment::$tabLevel--;
   		$output->add( $tabSetStr.'}' );
   
   	}
   
   	public function accept($visitor){}
   
   
   	public static function ReferencedArray($rules){
   		foreach($rules as $rule){
   			if( method_exists($rule, 'markReferenced') ){
   				$rule->markReferenced();
   			}
   		}
   	}
   
   
   	/**
   	 * Requires php 5.3+
   	 */
   	public static function __set_state($args){
   
   		$class = get_called_class();
   		$obj = new $class(null,null,null,null);
   		foreach($args as $key => $val){
   			$obj->$key = $val;
   		}
   		return $obj;
   	}
   
   }
    
   
   /**
    * Parser output
    *
    * @package Less
    * @subpackage output
    */
   class Less_Output{
   
   	/**
   	 * Output holder
   	 *
   	 * @var string
   	 */
   	protected $strs = array();
   
   	/**
   	 * Adds a chunk to the stack
   	 *
   	 * @param string $chunk The chunk to output
   	 * @param Less_FileInfo $fileInfo The file information
   	 * @param integer $index The index
   	 * @param mixed $mapLines
   	 */
   	public function add($chunk, $fileInfo = null, $index = 0, $mapLines = null){
   		$this->strs[] = $chunk;
   	}
   
   	/**
   	 * Is the output empty?
   	 *
   	 * @return boolean
   	 */
   	public function isEmpty(){
   		return count($this->strs) === 0;
   	}
   
   
   	/**
   	 * Converts the output to string
   	 *
   	 * @return string
   	 */
   	public function toString(){
   		return implode('',$this->strs);
   	}
   
   } 
   
   /**
    * Visitor
    *
    * @package Less
    * @subpackage visitor
    */
   class Less_Visitor{
   
   	protected $methods = array();
   	protected $_visitFnCache = array();
   
   	public function __construct(){
   		$this->_visitFnCache = get_class_methods(get_class($this));
   		$this->_visitFnCache = array_flip($this->_visitFnCache);
   	}
   
   	public function visitObj( $node ){
   
   		$funcName = 'visit'.$node->type;
   		if( isset($this->_visitFnCache[$funcName]) ){
   
   			$visitDeeper = true;
   			$this->$funcName( $node, $visitDeeper );
   
   			if( $visitDeeper ){
   				$node->accept($this);
   			}
   
   			$funcName = $funcName . "Out";
   			if( isset($this->_visitFnCache[$funcName]) ){
   				$this->$funcName( $node );
   			}
   
   		}else{
   			$node->accept($this);
   		}
   
   		return $node;
   	}
   
   	public function visitArray( $nodes ){
   
   		array_map( array($this,'visitObj'), $nodes);
   		return $nodes;
   	}
   }
   
    
   
   /**
    * Replacing Visitor
    *
    * @package Less
    * @subpackage visitor
    */
   class Less_VisitorReplacing extends Less_Visitor{
   
   	public function visitObj( $node ){
   
   		$funcName = 'visit'.$node->type;
   		if( isset($this->_visitFnCache[$funcName]) ){
   
   			$visitDeeper = true;
   			$node = $this->$funcName( $node, $visitDeeper );
   
   			if( $node ){
   				if( $visitDeeper && is_object($node) ){
   					$node->accept($this);
   				}
   
   				$funcName = $funcName . "Out";
   				if( isset($this->_visitFnCache[$funcName]) ){
   					$this->$funcName( $node );
   				}
   			}
   
   		}else{
   			$node->accept($this);
   		}
   
   		return $node;
   	}
   
   	public function visitArray( $nodes ){
   
   		$newNodes = array();
   		foreach($nodes as $node){
   			$evald = $this->visitObj($node);
   			if( $evald ){
   				if( is_array($evald) ){
   					self::flatten($evald,$newNodes);
   				}else{
   					$newNodes[] = $evald;
   				}
   			}
   		}
   		return $newNodes;
   	}
   
   	public function flatten( $arr, &$out ){
   
   		foreach($arr as $item){
   			if( !is_array($item) ){
   				$out[] = $item;
   				continue;
   			}
   
   			foreach($item as $nestedItem){
   				if( is_array($nestedItem) ){
   					self::flatten( $nestedItem, $out);
   				}else{
   					$out[] = $nestedItem;
   				}
   			}
   		}
   
   		return $out;
   	}
   
   }
   
   
    
   
   /**
    * Configurable
    *
    * @package Less
    * @subpackage Core
    */
   abstract class Less_Configurable {
   
   	/**
   	 * Array of options
   	 *
   	 * @var array
   	 */
   	protected $options = array();
   
   	/**
   	 * Array of default options
   	 *
   	 * @var array
   	 */
   	protected $defaultOptions = array();
   
   
   	/**
   	 * Set options
   	 *
   	 * If $options is an object it will be converted into an array by called
   	 * it's toArray method.
   	 *
   	 * @throws Exception
   	 * @param array|object $options
   	 *
   	 */
   	public function setOptions($options){
   		$options = array_intersect_key($options,$this->defaultOptions);
   		$this->options = array_merge($this->defaultOptions, $this->options, $options);
   	}
   
   
   	/**
   	 * Get an option value by name
   	 *
   	 * If the option is empty or not set a NULL value will be returned.
   	 *
   	 * @param string $name
   	 * @param mixed $default Default value if confiuration of $name is not present
   	 * @return mixed
   	 */
   	public function getOption($name, $default = null){
   		if(isset($this->options[$name])){
   			return $this->options[$name];
   		}
   		return $default;
   	}
   
   
   	/**
   	 * Set an option
   	 *
   	 * @param string $name
   	 * @param mixed $value
   	 */
   	public function setOption($name, $value){
   		$this->options[$name] = $value;
   	}
   
   } 
   
   /**
    * Alpha
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Alpha extends Less_Tree{
   	public $value;
   	public $type = 'Alpha';
   
   	public function __construct($val){
   		$this->value = $val;
   	}
   
   	//function accept( $visitor ){
   	//	$this->value = $visitor->visit( $this->value );
   	//}
   
   	public function compile($env){
   
   		if( is_object($this->value) ){
   			$this->value = $this->value->compile($env);
   		}
   
   		return $this;
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
   	public function genCSS( $output ){
   
   		$output->add( "alpha(opacity=" );
   
   		if( is_string($this->value) ){
   			$output->add( $this->value );
   		}else{
   			$this->value->genCSS( $output);
   		}
   
   		$output->add( ')' );
   	}
   
   	public function toCSS(){
   		return "alpha(opacity=" . (is_string($this->value) ? $this->value : $this->value->toCSS()) . ")";
   	}
   
   
   } 
   
   /**
    * Anonymous
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Anonymous extends Less_Tree{
   	public $value;
   	public $quote;
   	public $index;
   	public $mapLines;
   	public $currentFileInfo;
   	public $type = 'Anonymous';
   
   	/**
   	 * @param integer $index
   	 * @param boolean $mapLines
   	 */
   	public function __construct($value, $index = null, $currentFileInfo = null, $mapLines = null ){
   		$this->value = $value;
   		$this->index = $index;
   		$this->mapLines = $mapLines;
   		$this->currentFileInfo = $currentFileInfo;
   	}
   
   	public function compile(){
   		return new Less_Tree_Anonymous($this->value, $this->index, $this->currentFileInfo, $this->mapLines);
   	}
   
       public function compare($x){
   		if( !is_object($x) ){
   			return -1;
   		}
   
   		$left = $this->toCSS();
   		$right = $x->toCSS();
   
   		if( $left === $right ){
   			return 0;
   		}
   
   		return $left < $right ? -1 : 1;
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
   	public function genCSS( $output ){
   		$output->add( $this->value, $this->currentFileInfo, $this->index, $this->mapLines );
   	}
   
   	public function toCSS(){
   		return $this->value;
   	}
   
   }
    
   
   /**
    * Assignment
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Assignment extends Less_Tree{
   
   	public $key;
   	public $value;
   	public $type = 'Assignment';
   
       public function __construct($key, $val) {
   		$this->key = $key;
   		$this->value = $val;
   	}
   
       public function accept( $visitor ){
   		$this->value = $visitor->visitObj( $this->value );
   	}
   
   	public function compile($env) {
   		return new Less_Tree_Assignment( $this->key, $this->value->compile($env));
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
   	public function genCSS( $output ){
   		$output->add( $this->key . '=' );
   		$this->value->genCSS( $output );
   	}
   
   	public function toCss(){
   		return $this->key . '=' . $this->value->toCSS();
   	}
   }
    
   
   /**
    * Attribute
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Attribute extends Less_Tree{
   
   	public $key;
   	public $op;
   	public $value;
   	public $type = 'Attribute';
   
       public function __construct($key, $op, $value){
   		$this->key = $key;
   		$this->op = $op;
   		$this->value = $value;
   	}
   
       public function compile($env){
   
   		$key_obj = is_object($this->key);
   		$val_obj = is_object($this->value);
   
   		if( !$key_obj && !$val_obj ){
   			return $this;
   		}
   
   		return new Less_Tree_Attribute(
   			$key_obj ? $this->key->compile($env) : $this->key ,
   			$this->op,
   			$val_obj ? $this->value->compile($env) : $this->value);
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   		$output->add( $this->toCSS() );
   	}
   
       public function toCSS(){
   		$value = $this->key;
   
   		if( $this->op ){
   			$value .= $this->op;
   			$value .= (is_object($this->value) ? $this->value->toCSS() : $this->value);
   		}
   
   		return '[' . $value . ']';
   	}
   } 
   
   
   /**
    * Call
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Call extends Less_Tree{
       public $value;
   
       protected $name;
       protected $args;
       protected $index;
       protected $currentFileInfo;
       public $type = 'Call';
   
   	public function __construct($name, $args, $index, $currentFileInfo = null ){
   		$this->name = $name;
   		$this->args = $args;
   		$this->index = $index;
   		$this->currentFileInfo = $currentFileInfo;
   	}
   
       public function accept( $visitor ){
   		$this->args = $visitor->visitArray( $this->args );
   	}
   
       //
       // When evaluating a function call,
       // we either find the function in `tree.functions` [1],
       // in which case we call it, passing the  evaluated arguments,
       // or we simply print it out as it appeared originally [2].
       //
       // The *functions.js* file contains the built-in functions.
       //
       // The reason why we evaluate the arguments, is in the case where
       // we try to pass a variable to a function, like: `saturate(@color)`.
       // The function should receive the value, not the variable.
       //
       public function compile($env=null){
   		$args = array();
   		foreach($this->args as $a){
   			$args[] = $a->compile($env);
   		}
   
   		$nameLC = strtolower($this->name);
   		switch($nameLC){
   			case '%':
   			$nameLC = '_percent';
   			break;
   
   			case 'get-unit':
   			$nameLC = 'getunit';
   			break;
   
   			case 'data-uri':
   			$nameLC = 'datauri';
   			break;
   
   			case 'svg-gradient':
   			$nameLC = 'svggradient';
   			break;
   		}
   
   		$result = null;
   		if( $nameLC === 'default' ){
   			$result = Less_Tree_DefaultFunc::compile();
   
   		}else{
   
   			if( method_exists('Less_Functions',$nameLC) ){ // 1.
   				try {
   
   					$func = new Less_Functions($env, $this->currentFileInfo);
   					$result = call_user_func_array( array($func,$nameLC),$args);
   
   				} catch (Exception $e) {
   					throw new Less_Exception_Compiler('error evaluating function `' . $this->name . '` '.$e->getMessage().' index: '. $this->index);
   				}
   			} elseif( isset( $env->functions[$nameLC] ) && is_callable( $env->functions[$nameLC] ) ) {
   				try {
   					$result = call_user_func_array( $env->functions[$nameLC], $args );
   				} catch (Exception $e) {
   					throw new Less_Exception_Compiler('error evaluating function `' . $this->name . '` '.$e->getMessage().' index: '. $this->index);
   				}
   			}
   		}
   
   		if( $result !== null ){
   			return $result;
   		}
   
   
   		return new Less_Tree_Call( $this->name, $args, $this->index, $this->currentFileInfo );
       }
   
       /**
        * @see Less_Tree::genCSS
        */
   	public function genCSS( $output ){
   
   		$output->add( $this->name . '(', $this->currentFileInfo, $this->index );
   		$args_len = count($this->args);
   		for($i = 0; $i < $args_len; $i++ ){
   			$this->args[$i]->genCSS( $output );
   			if( $i + 1 < $args_len ){
   				$output->add( ', ' );
   			}
   		}
   
   		$output->add( ')' );
   	}
   
   
       //public function toCSS(){
       //    return $this->compile()->toCSS();
       //}
   
   }
    
   
   /**
    * Color
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Color extends Less_Tree{
   	public $rgb;
   	public $alpha;
   	public $isTransparentKeyword;
   	public $type = 'Color';
   
   	public function __construct($rgb, $a = 1, $isTransparentKeyword = null ){
   
   		if( $isTransparentKeyword ){
   			$this->rgb = $rgb;
   			$this->alpha = $a;
   			$this->isTransparentKeyword = true;
   			return;
   		}
   
   		$this->rgb = array();
   		if( is_array($rgb) ){
   			$this->rgb = $rgb;
   		}else if( strlen($rgb) == 6 ){
   			foreach(str_split($rgb, 2) as $c){
   				$this->rgb[] = hexdec($c);
   			}
   		}else{
   			foreach(str_split($rgb, 1) as $c){
   				$this->rgb[] = hexdec($c.$c);
   			}
   		}
   		$this->alpha = is_numeric($a) ? $a : 1;
   	}
   
   	public function compile(){
   		return $this;
   	}
   
   	public function luma(){
   		$r = $this->rgb[0] / 255;
   		$g = $this->rgb[1] / 255;
   		$b = $this->rgb[2] / 255;
   
   		$r = ($r <= 0.03928) ? $r / 12.92 : pow((($r + 0.055) / 1.055), 2.4);
   		$g = ($g <= 0.03928) ? $g / 12.92 : pow((($g + 0.055) / 1.055), 2.4);
   		$b = ($b <= 0.03928) ? $b / 12.92 : pow((($b + 0.055) / 1.055), 2.4);
   
   		return 0.2126 * $r + 0.7152 * $g + 0.0722 * $b;
   	}
   
   	/**
   	 * @see Less_Tree::genCSS
   	 */
   	public function genCSS( $output ){
   		$output->add( $this->toCSS() );
   	}
   
   	public function toCSS( $doNotCompress = false ){
   		$compress = Less_Parser::$options['compress'] && !$doNotCompress;
   		$alpha = Less_Functions::fround( $this->alpha );
   
   
   		//
   		// If we have some transparency, the only way to represent it
   		// is via `rgba`. Otherwise, we use the hex representation,
   		// which has better compatibility with older browsers.
   		// Values are capped between `0` and `255`, rounded and zero-padded.
   		//
   		if( $alpha < 1 ){
   			if( ( $alpha === 0 || $alpha === 0.0 ) && isset($this->isTransparentKeyword) && $this->isTransparentKeyword ){
   				return 'transparent';
   			}
   
   			$values = array();
   			foreach($this->rgb as $c){
   				$values[] = Less_Functions::clamp( round($c), 255);
   			}
   			$values[] = $alpha;
   
   			$glue = ($compress ? ',' : ', ');
   			return "rgba(" . implode($glue, $values) . ")";
   		}else{
   
   			$color = $this->toRGB();
   
   			if( $compress ){
   
   				// Convert color to short format
   				if( $color[1] === $color[2] && $color[3] === $color[4] && $color[5] === $color[6]) {
   					$color = '#'.$color[1] . $color[3] . $color[5];
   				}
   			}
   
   			return $color;
   		}
   	}
   
   	//
   	// Operations have to be done per-channel, if not,
   	// channels will spill onto each other. Once we have
   	// our result, in the form of an integer triplet,
   	// we create a new Color node to hold the result.
   	//
   
   	/**
   	 * @param string $op
   	 */
   	public function operate( $op, $other) {
   		$rgb = array();
   		$alpha = $this->alpha * (1 - $other->alpha) + $other->alpha;
   		for ($c = 0; $c < 3; $c++) {
   			$rgb[$c] = Less_Functions::operate( $op, $this->rgb[$c], $other->rgb[$c]);
   		}
   		return new Less_Tree_Color($rgb, $alpha);
   	}
   
   	public function toRGB(){
   		return $this->toHex($this->rgb);
   	}
   
   	public function toHSL(){
   		$r = $this->rgb[0] / 255;
   		$g = $this->rgb[1] / 255;
   		$b = $this->rgb[2] / 255;
   		$a = $this->alpha;
   
   		$max = max($r, $g, $b);
   		$min = min($r, $g, $b);
   		$l = ($max + $min) / 2;
   		$d = $max - $min;
   
   		$h = $s = 0;
   		if( $max !== $min ){
   			$s = $l > 0.5 ? $d / (2 - $max - $min) : $d / ($max + $min);
   
   			switch ($max) {
   				case $r: $h = ($g - $b) / $d + ($g < $b ? 6 : 0); break;
   				case $g: $h = ($b - $r) / $d + 2;				 break;
   				case $b: $h = ($r - $g) / $d + 4;				 break;
   			}
   			$h /= 6;
   		}
   		return array('h' => $h * 360, 's' => $s, 'l' => $l, 'a' => $a );
   	}
   
   	//Adapted from http://mjijackson.com/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript
       public function toHSV() {
   		$r = $this->rgb[0] / 255;
   		$g = $this->rgb[1] / 255;
   		$b = $this->rgb[2] / 255;
   		$a = $this->alpha;
   
   		$max = max($r, $g, $b);
   		$min = min($r, $g, $b);
   
   		$v = $max;
   
   		$d = $max - $min;
   		if ($max === 0) {
   			$s = 0;
   		} else {
   			$s = $d / $max;
   		}
   
   		$h = 0;
   		if( $max !== $min ){
   			switch($max){
   				case $r: $h = ($g - $b) / $d + ($g < $b ? 6 : 0); break;
   				case $g: $h = ($b - $r) / $d + 2; break;
   				case $b: $h = ($r - $g) / $d + 4; break;
   			}
   			$h /= 6;
   		}
   		return array('h'=> $h * 360, 's'=> $s, 'v'=> $v, 'a' => $a );
   	}
   
   	public function toARGB(){
   		$argb = array_merge( (array) Less_Parser::round($this->alpha * 255), $this->rgb);
   		return $this->toHex( $argb );
   	}
   
   	public function compare($x){
   
   		if( !property_exists( $x, 'rgb' ) ){
   			return -1;
   		}
   
   
   		return ($x->rgb[0] === $this->rgb[0] &&
   			$x->rgb[1] === $this->rgb[1] &&
   			$x->rgb[2] === $this->rgb[2] &&
   			$x->alpha === $this->alpha) ? 0 : -1;
   	}
   
       public function toHex( $v ){
   
   		$ret = '#';
   		foreach($v as $c){
   			$c = Less_Functions::clamp( Less_Parser::round($c), 255);
   			if( $c < 16 ){
   				$ret .= '0';
   			}
   			$ret .= dechex($c);
   		}
   
   		return $ret;
   	}
   
   
   	/**
   	 * @param string $keyword
   	 */
   	public static function fromKeyword( $keyword ){
   		$keyword = strtolower($keyword);
   
   		if( Less_Colors::hasOwnProperty($keyword) ){
   			// detect named color
   			return new Less_Tree_Color(substr(Less_Colors::color($keyword), 1));
   		}
   
   		if( $keyword === 'transparent' ){
   			return new Less_Tree_Color( array(0, 0, 0), 0, true);
   		}
   	}
   
   }
    
   
   /**
    * Comment
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Comment extends Less_Tree{
   
   	public $value;
   	public $silent;
   	public $isReferenced;
   	public $currentFileInfo;
   	public $type = 'Comment';
   
   	public function __construct($value, $silent, $index = null, $currentFileInfo = null ){
   		$this->value = $value;
   		$this->silent = !! $silent;
   		$this->currentFileInfo = $currentFileInfo;
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
   	public function genCSS( $output ){
   		//if( $this->debugInfo ){
   			//$output->add( tree.debugInfo($env, $this), $this->currentFileInfo, $this->index);
   		//}
   		$output->add( trim($this->value) );//TODO shouldn't need to trim, we shouldn't grab the \n
   	}
   
   	public function toCSS(){
   		return Less_Parser::$options['compress'] ? '' : $this->value;
   	}
   
   	public function isSilent(){
   		$isReference = ($this->currentFileInfo && isset($this->currentFileInfo['reference']) && (!isset($this->isReferenced) || !$this->isReferenced) );
   		$isCompressed = Less_Parser::$options['compress'] && !preg_match('/^\/\*!/', $this->value);
   		return $this->silent || $isReference || $isCompressed;
   	}
   
   	public function compile(){
   		return $this;
   	}
   
   	public function markReferenced(){
   		$this->isReferenced = true;
   	}
   
   }
    
   
   /**
    * Condition
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Condition extends Less_Tree{
   
   	public $op;
   	public $lvalue;
   	public $rvalue;
   	public $index;
   	public $negate;
   	public $type = 'Condition';
   
   	public function __construct($op, $l, $r, $i = 0, $negate = false) {
   		$this->op = trim($op);
   		$this->lvalue = $l;
   		$this->rvalue = $r;
   		$this->index = $i;
   		$this->negate = $negate;
   	}
   
   	public function accept($visitor){
   		$this->lvalue = $visitor->visitObj( $this->lvalue );
   		$this->rvalue = $visitor->visitObj( $this->rvalue );
   	}
   
       public function compile($env) {
   		$a = $this->lvalue->compile($env);
   		$b = $this->rvalue->compile($env);
   
   		switch( $this->op ){
   			case 'and':
   				$result = $a && $b;
   			break;
   
   			case 'or':
   				$result = $a || $b;
   			break;
   
   			default:
   				if( Less_Parser::is_method($a, 'compare') ){
   					$result = $a->compare($b);
   				}elseif( Less_Parser::is_method($b, 'compare') ){
   					$result = $b->compare($a);
   				}else{
   					throw new Less_Exception_Compiler('Unable to perform comparison', null, $this->index);
   				}
   
   				switch ($result) {
   					case -1:
   					$result = $this->op === '<' || $this->op === '=<' || $this->op === '<=';
   					break;
   
   					case  0:
   					$result = $this->op === '=' || $this->op === '>=' || $this->op === '=<' || $this->op === '<=';
   					break;
   
   					case  1:
   					$result = $this->op === '>' || $this->op === '>=';
   					break;
   				}
   			break;
   		}
   
   		return $this->negate ? !$result : $result;
       }
   
   }
    
   
   /**
    * DefaultFunc
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_DefaultFunc{
   
   	static $error_;
   	static $value_;
   
       public static function compile(){
   		if( self::$error_ ){
   			throw new Exception(self::$error_);
   		}
   		if( self::$value_ !== null ){
   			return self::$value_ ? new Less_Tree_Keyword('true') : new Less_Tree_Keyword('false');
   		}
   	}
   
       public static function value( $v ){
   		self::$value_ = $v;
   	}
   
       public static function error( $e ){
   		self::$error_ = $e;
   	}
   
       public static function reset(){
   		self::$value_ = self::$error_ = null;
   	}
   } 
   
   /**
    * DetachedRuleset
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_DetachedRuleset extends Less_Tree{
   
   	public $ruleset;
   	public $frames;
   	public $type = 'DetachedRuleset';
   
       public function __construct( $ruleset, $frames = null ){
   		$this->ruleset = $ruleset;
   		$this->frames = $frames;
   	}
   
       public function accept($visitor) {
   		$this->ruleset = $visitor->visitObj($this->ruleset);
   	}
   
       public function compile($env){
   		if( $this->frames ){
   			$frames = $this->frames;
   		}else{
   			$frames = $env->frames;
   		}
   		return new Less_Tree_DetachedRuleset($this->ruleset, $frames);
   	}
   
       public function callEval($env) {
   		if( $this->frames ){
   			return $this->ruleset->compile( $env->copyEvalEnv( array_merge($this->frames,$env->frames) ) );
   		}
   		return $this->ruleset->compile( $env );
   	}
   }
   
    
   
   /**
    * Dimension
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Dimension extends Less_Tree{
   
   	public $value;
   	public $unit;
   	public $type = 'Dimension';
   
       public function __construct($value, $unit = null){
           $this->value = floatval($value);
   
   		if( $unit && ($unit instanceof Less_Tree_Unit) ){
   			$this->unit = $unit;
   		}elseif( $unit ){
   			$this->unit = new Less_Tree_Unit( array($unit) );
   		}else{
   			$this->unit = new Less_Tree_Unit( );
   		}
       }
   
       public function accept( $visitor ){
   		$this->unit = $visitor->visitObj( $this->unit );
   	}
   
       public function compile(){
           return $this;
       }
   
       public function toColor() {
           return new Less_Tree_Color(array($this->value, $this->value, $this->value));
       }
   
       /**
        * @see Less_Tree::genCSS
        */
   	public function genCSS( $output ){
   
   		if( Less_Parser::$options['strictUnits'] && !$this->unit->isSingular() ){
   			throw new Less_Exception_Compiler("Multiple units in dimension. Correct the units or use the unit function. Bad unit: ".$this->unit->toString());
   		}
   
   		$value = Less_Functions::fround( $this->value );
   		$strValue = (string)$value;
   
   		if( $value !== 0 && $value < 0.000001 && $value > -0.000001 ){
   			// would be output 1e-6 etc.
   			$strValue = number_format($strValue,10);
   			$strValue = preg_replace('/\.?0+$/','', $strValue);
   		}
   
   		if( Less_Parser::$options['compress'] ){
   			// Zero values doesn't need a unit
   			if( $value === 0 && $this->unit->isLength() ){
   				$output->add( $strValue );
   				return $strValue;
   			}
   
   			// Float values doesn't need a leading zero
   			if( $value > 0 && $value < 1 && $strValue[0] === '0' ){
   				$strValue = substr($strValue,1);
   			}
   		}
   
   		$output->add( $strValue );
   		$this->unit->genCSS( $output );
   	}
   
       public function __toString(){
           return $this->toCSS();
       }
   
       // In an operation between two Dimensions,
       // we default to the first Dimension's unit,
       // so `1px + 2em` will yield `3px`.
   
       /**
        * @param string $op
        */
       public function operate( $op, $other){
   
   		$value = Less_Functions::operate( $op, $this->value, $other->value);
   		$unit = clone $this->unit;
   
   		if( $op === '+' || $op === '-' ){
   
   			if( !$unit->numerator && !$unit->denominator ){
   				$unit->numerator = $other->unit->numerator;
   				$unit->denominator = $other->unit->denominator;
   			}elseif( !$other->unit->numerator && !$other->unit->denominator ){
   				// do nothing
   			}else{
   				$other = $other->convertTo( $this->unit->usedUnits());
   
   				if( Less_Parser::$options['strictUnits'] && $other->unit->toString() !== $unit->toCSS() ){
   					throw new Less_Exception_Compiler("Incompatible units. Change the units or use the unit function. Bad units: '" . $unit->toString() . "' and " . $other->unit->toString() . "'.");
   				}
   
   				$value = Less_Functions::operate( $op, $this->value, $other->value);
   			}
   		}elseif( $op === '*' ){
   			$unit->numerator = array_merge($unit->numerator, $other->unit->numerator);
   			$unit->denominator = array_merge($unit->denominator, $other->unit->denominator);
   			sort($unit->numerator);
   			sort($unit->denominator);
   			$unit->cancel();
   		}elseif( $op === '/' ){
   			$unit->numerator = array_merge($unit->numerator, $other->unit->denominator);
   			$unit->denominator = array_merge($unit->denominator, $other->unit->numerator);
   			sort($unit->numerator);
   			sort($unit->denominator);
   			$unit->cancel();
   		}
   		return new Less_Tree_Dimension( $value, $unit);
       }
   
   	public function compare($other) {
   		if ($other instanceof Less_Tree_Dimension) {
   
   			if( $this->unit->isEmpty() || $other->unit->isEmpty() ){
   				$a = $this;
   				$b = $other;
   			} else {
   				$a = $this->unify();
   				$b = $other->unify();
   				if( $a->unit->compare($b->unit) !== 0 ){
   					return -1;
   				}
   			}
   			$aValue = $a->value;
   			$bValue = $b->value;
   
   			if ($bValue > $aValue) {
   				return -1;
   			} elseif ($bValue < $aValue) {
   				return 1;
   			} else {
   				return 0;
   			}
   		} else {
   			return -1;
   		}
   	}
   
       public function unify() {
   		return $this->convertTo(array('length'=> 'px', 'duration'=> 's', 'angle' => 'rad' ));
   	}
   
       public function convertTo($conversions) {
   		$value = $this->value;
   		$unit = clone $this->unit;
   
   		if( is_string($conversions) ){
   			$derivedConversions = array();
   			foreach( Less_Tree_UnitConversions::$groups as $i ){
   				if( isset(Less_Tree_UnitConversions::${$i}[$conversions]) ){
   					$derivedConversions = array( $i => $conversions);
   				}
   			}
   			$conversions = $derivedConversions;
   		}
   
   
   		foreach($conversions as $groupName => $targetUnit){
   			$group = Less_Tree_UnitConversions::${$groupName};
   
   			//numerator
   			foreach($unit->numerator as $i => $atomicUnit){
   				$atomicUnit = $unit->numerator[$i];
   				if( !isset($group[$atomicUnit]) ){
   					continue;
   				}
   
   				$value = $value * ($group[$atomicUnit] / $group[$targetUnit]);
   
   				$unit->numerator[$i] = $targetUnit;
   			}
   
   			//denominator
   			foreach($unit->denominator as $i => $atomicUnit){
   				$atomicUnit = $unit->denominator[$i];
   				if( !isset($group[$atomicUnit]) ){
   					continue;
   				}
   
   				$value = $value / ($group[$atomicUnit] / $group[$targetUnit]);
   
   				$unit->denominator[$i] = $targetUnit;
   			}
   		}
   
   		$unit->cancel();
   
   		return new Less_Tree_Dimension( $value, $unit);
       }
   }
    
   
   /**
    * Directive
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Directive extends Less_Tree{
   
   	public $name;
   	public $value;
   	public $rules;
   	public $index;
   	public $isReferenced;
   	public $currentFileInfo;
   	public $debugInfo;
   	public $type = 'Directive';
   
   	public function __construct($name, $value = null, $rules, $index = null, $currentFileInfo = null, $debugInfo = null ){
   		$this->name = $name;
   		$this->value = $value;
   		if( $rules ){
   			$this->rules = $rules;
   			$this->rules->allowImports = true;
   		}
   
   		$this->index = $index;
   		$this->currentFileInfo = $currentFileInfo;
   		$this->debugInfo = $debugInfo;
   	}
   
   
       public function accept( $visitor ){
   		if( $this->rules ){
   			$this->rules = $visitor->visitObj( $this->rules );
   		}
   		if( $this->value ){
   			$this->value = $visitor->visitObj( $this->value );
   		}
   	}
   
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   		$value = $this->value;
   		$rules = $this->rules;
   		$output->add( $this->name, $this->currentFileInfo, $this->index );
   		if( $this->value ){
   			$output->add(' ');
   			$this->value->genCSS($output);
   		}
   		if( $this->rules ){
   			Less_Tree::outputRuleset( $output, array($this->rules));
   		} else {
   			$output->add(';');
   		}
   	}
   
   	public function compile($env){
   
   		$value = $this->value;
   		$rules = $this->rules;
   		if( $value ){
   			$value = $value->compile($env);
   		}
   
   		if( $rules ){
   			$rules = $rules->compile($env);
   			$rules->root = true;
   		}
   
   		return new Less_Tree_Directive( $this->name, $value, $rules, $this->index, $this->currentFileInfo, $this->debugInfo );
   	}
   
   
   	public function variable($name){
   		if( $this->rules ){
   			return $this->rules->variable($name);
   		}
   	}
   
   	public function find($selector){
   		if( $this->rules ){
   			return $this->rules->find($selector, $this);
   		}
   	}
   
   	//rulesets: function () { if (this.rules) return tree.Ruleset.prototype.rulesets.apply(this.rules); },
   
   	public function markReferenced(){
   		$this->isReferenced = true;
   		if( $this->rules ){
   			Less_Tree::ReferencedArray($this->rules->rules);
   		}
   	}
   
   }
    
   
   /**
    * Element
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Element extends Less_Tree{
   
   	public $combinator = '';
   	public $value = '';
   	public $index;
   	public $currentFileInfo;
   	public $type = 'Element';
   
   	public $value_is_object = false;
   
   	public function __construct($combinator, $value, $index = null, $currentFileInfo = null ){
   
   		$this->value = $value;
   		$this->value_is_object = is_object($value);
   
   		if( $combinator ){
   			$this->combinator = $combinator;
   		}
   
   		$this->index = $index;
   		$this->currentFileInfo = $currentFileInfo;
   	}
   
       public function accept( $visitor ){
   		if( $this->value_is_object ){ //object or string
   			$this->value = $visitor->visitObj( $this->value );
   		}
   	}
   
   	public function compile($env){
   
   		if( Less_Environment::$mixin_stack ){
   			return new Less_Tree_Element($this->combinator, ($this->value_is_object ? $this->value->compile($env) : $this->value), $this->index, $this->currentFileInfo );
   		}
   
   		if( $this->value_is_object ){
   			$this->value = $this->value->compile($env);
   		}
   
   		return $this;
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
   	public function genCSS( $output ){
   		$output->add( $this->toCSS(), $this->currentFileInfo, $this->index );
   	}
   
   	public function toCSS(){
   
   		if( $this->value_is_object ){
   			$value = $this->value->toCSS();
   		}else{
   			$value = $this->value;
   		}
   
   
   		if( $value === '' && $this->combinator && $this->combinator === '&' ){
   			return '';
   		}
   
   
   		return Less_Environment::$_outputMap[$this->combinator] . $value;
   	}
   
   }
    
   
   /**
    * Expression
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Expression extends Less_Tree{
   
   	public $value = array();
   	public $parens = false;
   	public $parensInOp = false;
   	public $type = 'Expression';
   
   	public function __construct( $value, $parens = null ){
   		$this->value = $value;
   		$this->parens = $parens;
   	}
   
       public function accept( $visitor ){
   		$this->value = $visitor->visitArray( $this->value );
   	}
   
   	public function compile($env) {
   
   		$doubleParen = false;
   
   		if( $this->parens && !$this->parensInOp ){
   			Less_Environment::$parensStack++;
   		}
   
   		$returnValue = null;
   		if( $this->value ){
   
   			$count = count($this->value);
   
   			if( $count > 1 ){
   
   				$ret = array();
   				foreach($this->value as $e){
   					$ret[] = $e->compile($env);
   				}
   				$returnValue = new Less_Tree_Expression($ret);
   
   			}else{
   
   				if( ($this->value[0] instanceof Less_Tree_Expression) && $this->value[0]->parens && !$this->value[0]->parensInOp ){
   					$doubleParen = true;
   				}
   
   				$returnValue = $this->value[0]->compile($env);
   			}
   
   		} else {
   			$returnValue = $this;
   		}
   
   		if( $this->parens ){
   			if( !$this->parensInOp ){
   				Less_Environment::$parensStack--;
   
   			}elseif( !Less_Environment::isMathOn() && !$doubleParen ){
   				$returnValue = new Less_Tree_Paren($returnValue);
   
   			}
   		}
   		return $returnValue;
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   		$val_len = count($this->value);
   		for( $i = 0; $i < $val_len; $i++ ){
   			$this->value[$i]->genCSS( $output );
   			if( $i + 1 < $val_len ){
   				$output->add( ' ' );
   			}
   		}
   	}
   
       public function throwAwayComments() {
   
   		if( is_array($this->value) ){
   			$new_value = array();
   			foreach($this->value as $v){
   				if( $v instanceof Less_Tree_Comment ){
   					continue;
   				}
   				$new_value[] = $v;
   			}
   			$this->value = $new_value;
   		}
   	}
   }
    
   
   /**
    * Extend
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Extend extends Less_Tree{
   
   	public $selector;
   	public $option;
   	public $index;
   	public $selfSelectors = array();
   	public $allowBefore;
   	public $allowAfter;
   	public $firstExtendOnThisSelectorPath;
   	public $type = 'Extend';
   	public $ruleset;
   
   
   	public $object_id;
   	public $parent_ids = array();
   
   	/**
   	 * @param integer $index
   	 */
       public function __construct($selector, $option, $index){
   		static $i = 0;
   		$this->selector = $selector;
   		$this->option = $option;
   		$this->index = $index;
   
   		switch($option){
   			case "all":
   				$this->allowBefore = true;
   				$this->allowAfter = true;
   			break;
   			default:
   				$this->allowBefore = false;
   				$this->allowAfter = false;
   			break;
   		}
   
   		$this->object_id = $i++;
   		$this->parent_ids = array($this->object_id);
   	}
   
       public function accept( $visitor ){
   		$this->selector = $visitor->visitObj( $this->selector );
   	}
   
       public function compile( $env ){
   		Less_Parser::$has_extends = true;
   		$this->selector = $this->selector->compile($env);
   		return $this;
   		//return new Less_Tree_Extend( $this->selector->compile($env), $this->option, $this->index);
   	}
   
       public function findSelfSelectors( $selectors ){
   		$selfElements = array();
   
   
   		for( $i = 0, $selectors_len = count($selectors); $i < $selectors_len; $i++ ){
   			$selectorElements = $selectors[$i]->elements;
   			// duplicate the logic in genCSS function inside the selector node.
   			// future TODO - move both logics into the selector joiner visitor
   			if( $i && $selectorElements && $selectorElements[0]->combinator === "") {
   				$selectorElements[0]->combinator = ' ';
   			}
   			$selfElements = array_merge( $selfElements, $selectors[$i]->elements );
   		}
   
   		$this->selfSelectors = array(new Less_Tree_Selector($selfElements));
   	}
   
   } 
   
   /**
    * CSS @import node
    *
    * The general strategy here is that we don't want to wait
    * for the parsing to be completed, before we start importing
    * the file. That's because in the context of a browser,
    * most of the time will be spent waiting for the server to respond.
    *
    * On creation, we push the import path to our import queue, though
    * `import,push`, we also pass it a callback, which it'll call once
    * the file has been fetched, and parsed.
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Import extends Less_Tree{
   
   	public $options;
   	public $index;
   	public $path;
   	public $features;
   	public $currentFileInfo;
   	public $css;
   	public $skip;
   	public $root;
   	public $type = 'Import';
   
       public function __construct($path, $features, $options, $index, $currentFileInfo = null ){
   		$this->options = $options;
   		$this->index = $index;
   		$this->path = $path;
   		$this->features = $features;
   		$this->currentFileInfo = $currentFileInfo;
   
   		if( is_array($options) ){
   			$this->options += array('inline'=>false);
   
   			if( isset($this->options['less']) || $this->options['inline'] ){
   				$this->css = !isset($this->options['less']) || !$this->options['less'] || $this->options['inline'];
   			} else {
   				$pathValue = $this->getPath();
   				if( $pathValue && preg_match('/css([\?;].*)?$/',$pathValue) ){
   					$this->css = true;
   				}
   			}
   		}
   	}
   
   //
   // The actual import node doesn't return anything, when converted to CSS.
   // The reason is that it's used at the evaluation stage, so that the rules
   // it imports can be treated like any other rules.
   //
   // In `eval`, we make sure all Import nodes get evaluated, recursively, so
   // we end up with a flat structure, which can easily be imported in the parent
   // ruleset.
   //
   
       public function accept($visitor){
   
   		if( $this->features ){
   			$this->features = $visitor->visitObj($this->features);
   		}
   		$this->path = $visitor->visitObj($this->path);
   
   		if( !$this->options['inline'] && $this->root ){
   			$this->root = $visitor->visit($this->root);
   		}
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   		if( $this->css ){
   
   			$output->add( '@import ', $this->currentFileInfo, $this->index );
   
   			$this->path->genCSS( $output );
   			if( $this->features ){
   				$output->add( ' ' );
   				$this->features->genCSS( $output );
   			}
   			$output->add( ';' );
   		}
   	}
   
       public function toCSS(){
   		$features = $this->features ? ' ' . $this->features->toCSS() : '';
   
   		if ($this->css) {
   			return "@import " . $this->path->toCSS() . $features . ";\n";
   		} else {
   			return "";
   		}
   	}
   
   	/**
   	 * @return string
   	 */
       public function getPath(){
   		if ($this->path instanceof Less_Tree_Quoted) {
   			$path = $this->path->value;
   			$path = ( isset($this->css) || preg_match('/(\.[a-z]*$)|([\?;].*)$/',$path)) ? $path : $path . '.less';
   		} else if ($this->path instanceof Less_Tree_URL) {
   			$path = $this->path->value->value;
   		}else{
   			return null;
   		}
   
   		//remove query string and fragment
   		return preg_replace('/[\?#][^\?]*$/','',$path);
   	}
   
       public function compileForImport( $env ){
   		return new Less_Tree_Import( $this->path->compile($env), $this->features, $this->options, $this->index, $this->currentFileInfo);
   	}
   
       public function compilePath($env) {
   		$path = $this->path->compile($env);
   		$rootpath = '';
   		if( $this->currentFileInfo && $this->currentFileInfo['rootpath'] ){
   			$rootpath = $this->currentFileInfo['rootpath'];
   		}
   
   
   		if( !($path instanceof Less_Tree_URL) ){
   			if( $rootpath ){
   				$pathValue = $path->value;
   				// Add the base path if the import is relative
   				if( $pathValue && Less_Environment::isPathRelative($pathValue) ){
   					$path->value = $this->currentFileInfo['uri_root'].$pathValue;
   				}
   			}
   			$path->value = Less_Environment::normalizePath($path->value);
   		}
   
   
   
   		return $path;
   	}
   
       public function compile( $env ){
   
   		$evald = $this->compileForImport($env);
   
   		//get path & uri
   		$path_and_uri = null;
   		if( is_callable(Less_Parser::$options['import_callback']) ){
   			$path_and_uri = call_user_func(Less_Parser::$options['import_callback'],$evald);
   		}
   
   		if( !$path_and_uri ){
   			$path_and_uri = $evald->PathAndUri();
   		}
   
   		if( $path_and_uri ){
   			list($full_path, $uri) = $path_and_uri;
   		}else{
   			$full_path = $uri = $evald->getPath();
   		}
   
   
   		//import once
   		if( $evald->skip( $full_path, $env) ){
   			return array();
   		}
   
   		if( $this->options['inline'] ){
   			//todo needs to reference css file not import
   			//$contents = new Less_Tree_Anonymous($this->root, 0, array('filename'=>$this->importedFilename), true );
   
   			Less_Parser::AddParsedFile($full_path);
   			$contents = new Less_Tree_Anonymous( file_get_contents($full_path), 0, array(), true );
   
   			if( $this->features ){
   				return new Less_Tree_Media( array($contents), $this->features->value );
   			}
   
   			return array( $contents );
   		}
   
   		// optional (need to be before "CSS" to support optional CSS imports. CSS should be checked only if empty($this->currentFileInfo))
   		if( isset($this->options['optional']) && $this->options['optional'] && !file_exists($full_path) && (!$evald->css || !empty($this->currentFileInfo))) {
   			return array();
   		}
   
   
   		// css ?
   		if( $evald->css ){
   			$features = ( $evald->features ? $evald->features->compile($env) : null );
   			return new Less_Tree_Import( $this->compilePath( $env), $features, $this->options, $this->index);
   		}
   
   
   		return $this->ParseImport( $full_path, $uri, $env );
   	}
   
   
   	/**
   	 * Using the import directories, get the full absolute path and uri of the import
   	 *
   	 * @param Less_Tree_Import $evald
   	 */
       public function PathAndUri(){
   
   		$evald_path = $this->getPath();
   
   		if( $evald_path ){
   
   			$import_dirs = array();
   
   			if( Less_Environment::isPathRelative($evald_path) ){
   				//if the path is relative, the file should be in the current directory
   				$import_dirs[ $this->currentFileInfo['currentDirectory'] ] = $this->currentFileInfo['uri_root'];
   
   			}else{
   				//otherwise, the file should be relative to the server root
   				$import_dirs[ $this->currentFileInfo['entryPath'] ] = $this->currentFileInfo['entryUri'];
   
   				//if the user supplied entryPath isn't the actual root
   				$import_dirs[ $_SERVER['DOCUMENT_ROOT'] ] = '';
   
   			}
   
   			// always look in user supplied import directories
   			$import_dirs = array_merge( $import_dirs, Less_Parser::$options['import_dirs'] );
   
   
   			foreach( $import_dirs as $rootpath => $rooturi){
   				if( is_callable($rooturi) ){
   					list($path, $uri) = call_user_func($rooturi, $evald_path);
   					if( is_string($path) ){
   						$full_path = $path;
   						return array( $full_path, $uri );
   					}
   				}elseif( !empty($rootpath) ){
   
   
   					if( $rooturi ){
   						if( strpos($evald_path,$rooturi) === 0 ){
   							$evald_path = substr( $evald_path, strlen($rooturi) );
   						}
   					}
   
   					$path = rtrim($rootpath,'/\\').'/'.ltrim($evald_path,'/\\');
   
   					if( file_exists($path) ){
   						$full_path = Less_Environment::normalizePath($path);
   						$uri = Less_Environment::normalizePath(dirname($rooturi.$evald_path));
   						return array( $full_path, $uri );
   					} elseif( file_exists($path.'.less') ){
   						$full_path = Less_Environment::normalizePath($path.'.less');
   						$uri = Less_Environment::normalizePath(dirname($rooturi.$evald_path.'.less'));
   						return array( $full_path, $uri );
   					}
   				}
   			}
   		}
   	}
   
   
   	/**
   	 * Parse the import url and return the rules
   	 *
   	 * @return Less_Tree_Media|array
   	 */
       public function ParseImport( $full_path, $uri, $env ){
   
   		$import_env = clone $env;
   		if( (isset($this->options['reference']) && $this->options['reference']) || isset($this->currentFileInfo['reference']) ){
   			$import_env->currentFileInfo['reference'] = true;
   		}
   
   		if( (isset($this->options['multiple']) && $this->options['multiple']) ){
   			$import_env->importMultiple = true;
   		}
   
   		$parser = new Less_Parser($import_env);
   		$root = $parser->parseFile($full_path, $uri, true);
   
   
   		$ruleset = new Less_Tree_Ruleset(array(), $root->rules );
   		$ruleset->evalImports($import_env);
   
   		return $this->features ? new Less_Tree_Media($ruleset->rules, $this->features->value) : $ruleset->rules;
   	}
   
   
   	/**
   	 * Should the import be skipped?
   	 *
   	 * @return boolean|null
   	 */
   	private function Skip($path, $env){
   
   		$path = Less_Parser::winPath(realpath($path));
   
   		if( $path && Less_Parser::FileParsed($path) ){
   
   			if( isset($this->currentFileInfo['reference']) ){
   				return true;
   			}
   
   			return !isset($this->options['multiple']) && !$env->importMultiple;
   		}
   
   	}
   }
    
   
   /**
    * Javascript
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Javascript extends Less_Tree{
   
   	public $type = 'Javascript';
   	public $escaped;
   	public $expression;
   	public $index;
   
   	/**
   	 * @param boolean $index
   	 * @param boolean $escaped
   	 */
   	public function __construct($string, $index, $escaped){
   		$this->escaped = $escaped;
   		$this->expression = $string;
   		$this->index = $index;
   	}
   
   	public function compile(){
   		return new Less_Tree_Anonymous('/* Sorry, can not do JavaScript evaluation in PHP... :( */');
   	}
   
   }
    
   
   /**
    * Keyword
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Keyword extends Less_Tree{
   
   	public $value;
   	public $type = 'Keyword';
   
   	/**
   	 * @param string $value
   	 */
   	public function __construct($value){
   		$this->value = $value;
   	}
   
   	public function compile(){
   		return $this;
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
   	public function genCSS( $output ){
   
   		if( $this->value === '%') {
   			throw new Less_Exception_Compiler("Invalid % without number");
   		}
   
   		$output->add( $this->value );
   	}
   
   	public function compare($other) {
   		if ($other instanceof Less_Tree_Keyword) {
   			return $other->value === $this->value ? 0 : 1;
   		} else {
   			return -1;
   		}
   	}
   }
    
   
   /**
    * Media
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Media extends Less_Tree{
   
   	public $features;
   	public $rules;
   	public $index;
   	public $currentFileInfo;
   	public $isReferenced;
   	public $type = 'Media';
   
   	public function __construct($value = array(), $features = array(), $index = null, $currentFileInfo = null ){
   
   		$this->index = $index;
   		$this->currentFileInfo = $currentFileInfo;
   
   		$selectors = $this->emptySelectors();
   
   		$this->features = new Less_Tree_Value($features);
   
   		$this->rules = array(new Less_Tree_Ruleset($selectors, $value));
   		$this->rules[0]->allowImports = true;
   	}
   
       public function accept( $visitor ){
   		$this->features = $visitor->visitObj($this->features);
   		$this->rules = $visitor->visitArray($this->rules);
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   
   		$output->add( '@media ', $this->currentFileInfo, $this->index );
   		$this->features->genCSS( $output );
   		Less_Tree::outputRuleset( $output, $this->rules);
   
   	}
   
   	public function compile($env) {
   
   		$media = new Less_Tree_Media(array(), array(), $this->index, $this->currentFileInfo );
   
   		$strictMathBypass = false;
   		if( Less_Parser::$options['strictMath'] === false) {
   			$strictMathBypass = true;
   			Less_Parser::$options['strictMath'] = true;
   		}
   
   		$media->features = $this->features->compile($env);
   
   		if( $strictMathBypass ){
   			Less_Parser::$options['strictMath'] = false;
   		}
   
   		$env->mediaPath[] = $media;
   		$env->mediaBlocks[] = $media;
   
   		array_unshift($env->frames, $this->rules[0]);
   		$media->rules = array($this->rules[0]->compile($env));
   		array_shift($env->frames);
   
   		array_pop($env->mediaPath);
   
   		return !$env->mediaPath ? $media->compileTop($env) : $media->compileNested($env);
   	}
   
   	public function variable($name) {
   		return $this->rules[0]->variable($name);
   	}
   
   	public function find($selector) {
   		return $this->rules[0]->find($selector, $this);
   	}
   
   	public function emptySelectors(){
   		$el = new Less_Tree_Element('','&', $this->index, $this->currentFileInfo );
   		$sels = array( new Less_Tree_Selector(array($el), array(), null, $this->index, $this->currentFileInfo) );
   		$sels[0]->mediaEmpty = true;
           return $sels;
   	}
   
   	public function markReferenced(){
   		$this->rules[0]->markReferenced();
   		$this->isReferenced = true;
   		Less_Tree::ReferencedArray($this->rules[0]->rules);
   	}
   
   	// evaltop
   	public function compileTop($env) {
   		$result = $this;
   
   		if (count($env->mediaBlocks) > 1) {
   			$selectors = $this->emptySelectors();
   			$result = new Less_Tree_Ruleset($selectors, $env->mediaBlocks);
   			$result->multiMedia = true;
   		}
   
   		$env->mediaBlocks = array();
   		$env->mediaPath = array();
   
   		return $result;
   	}
   
   	public function compileNested($env) {
   		$path = array_merge($env->mediaPath, array($this));
   
   		// Extract the media-query conditions separated with `,` (OR).
   		foreach ($path as $key => $p) {
   			$value = $p->features instanceof Less_Tree_Value ? $p->features->value : $p->features;
   			$path[$key] = is_array($value) ? $value : array($value);
   		}
   
   		// Trace all permutations to generate the resulting media-query.
   		//
   		// (a, b and c) with nested (d, e) ->
   		//	a and d
   		//	a and e
   		//	b and c and d
   		//	b and c and e
   
   		$permuted = $this->permute($path);
   		$expressions = array();
   		foreach($permuted as $path){
   
   			for( $i=0, $len=count($path); $i < $len; $i++){
   				$path[$i] = Less_Parser::is_method($path[$i], 'toCSS') ? $path[$i] : new Less_Tree_Anonymous($path[$i]);
   			}
   
   			for( $i = count($path) - 1; $i > 0; $i-- ){
   				array_splice($path, $i, 0, array(new Less_Tree_Anonymous('and')));
   			}
   
   			$expressions[] = new Less_Tree_Expression($path);
   		}
   		$this->features = new Less_Tree_Value($expressions);
   
   
   
   		// Fake a tree-node that doesn't output anything.
   		return new Less_Tree_Ruleset(array(), array());
   	}
   
   	public function permute($arr) {
   		if (!$arr)
   			return array();
   
   		if (count($arr) == 1)
   			return $arr[0];
   
   		$result = array();
   		$rest = $this->permute(array_slice($arr, 1));
   		foreach ($rest as $r) {
   			foreach ($arr[0] as $a) {
   				$result[] = array_merge(
   					is_array($a) ? $a : array($a),
   					is_array($r) ? $r : array($r)
   				);
   			}
   		}
   
   		return $result;
   	}
   
       public function bubbleSelectors($selectors) {
   
   		if( !$selectors) return;
   
   		$this->rules = array(new Less_Tree_Ruleset( $selectors, array($this->rules[0])));
   	}
   
   }
    
   
   /**
    * A simple css name-value pair
    * ex: width:100px;
    *
    * In bootstrap, there are about 600-1,000 simple name-value pairs (depending on how forgiving the match is) -vs- 6,020 dynamic rules (Less_Tree_Rule)
    * Using the name-value object can speed up bootstrap compilation slightly, but it breaks color keyword interpretation: color:red -> color:#FF0000;
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_NameValue extends Less_Tree{
   
   	public $name;
   	public $value;
   	public $index;
   	public $currentFileInfo;
   	public $type = 'NameValue';
   	public $important = '';
   
   	public function __construct($name, $value = null, $index = null, $currentFileInfo = null ){
   		$this->name = $name;
   		$this->value = $value;
   		$this->index = $index;
   		$this->currentFileInfo = $currentFileInfo;
   	}
   
       public function genCSS( $output ){
   
   		$output->add(
   			$this->name
   			. Less_Environment::$_outputMap[': ']
   			. $this->value
   			. $this->important
   			. (((Less_Environment::$lastRule && Less_Parser::$options['compress'])) ? "" : ";")
   			, $this->currentFileInfo, $this->index);
   	}
   
   	public function compile ($env){
   		return $this;
   	}
   
   	public function makeImportant(){
   		$new = new Less_Tree_NameValue($this->name, $this->value, $this->index, $this->currentFileInfo);
   		$new->important = ' !important';
   		return $new;
   	}
   
   
   }
    
   
   /**
    * Negative
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Negative extends Less_Tree{
   
   	public $value;
   	public $type = 'Negative';
   
       public function __construct($node){
   		$this->value = $node;
   	}
   
   	//function accept($visitor) {
   	//	$this->value = $visitor->visit($this->value);
   	//}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   		$output->add( '-' );
   		$this->value->genCSS( $output );
   	}
   
       public function compile($env) {
   		if( Less_Environment::isMathOn() ){
   			$ret = new Less_Tree_Operation('*', array( new Less_Tree_Dimension(-1), $this->value ) );
   			return $ret->compile($env);
   		}
   		return new Less_Tree_Negative( $this->value->compile($env) );
   	}
   } 
   
   /**
    * Operation
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Operation extends Less_Tree{
   
   	public $op;
   	public $operands;
   	public $isSpaced;
   	public $type = 'Operation';
   
   	/**
   	 * @param string $op
   	 */
   	public function __construct($op, $operands, $isSpaced = false){
   		$this->op = trim($op);
   		$this->operands = $operands;
   		$this->isSpaced = $isSpaced;
   	}
   
       public function accept($visitor) {
   		$this->operands = $visitor->visitArray($this->operands);
   	}
   
   	public function compile($env){
   		$a = $this->operands[0]->compile($env);
   		$b = $this->operands[1]->compile($env);
   
   
   		if( Less_Environment::isMathOn() ){
   
   			if( $a instanceof Less_Tree_Dimension && $b instanceof Less_Tree_Color ){
   				$a = $a->toColor();
   
   			}elseif( $b instanceof Less_Tree_Dimension && $a instanceof Less_Tree_Color ){
   				$b = $b->toColor();
   
   			}
   
   			if( !method_exists($a,'operate') ){
   				throw new Less_Exception_Compiler("Operation on an invalid type");
   			}
   
   			return $a->operate( $this->op, $b);
   		}
   
   		return new Less_Tree_Operation($this->op, array($a, $b), $this->isSpaced );
   	}
   
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   		$this->operands[0]->genCSS( $output );
   		if( $this->isSpaced ){
   			$output->add( " " );
   		}
   		$output->add( $this->op );
   		if( $this->isSpaced ){
   			$output->add( ' ' );
   		}
   		$this->operands[1]->genCSS( $output );
   	}
   
   }
    
   
   /**
    * Paren
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Paren extends Less_Tree{
   
   	public $value;
   	public $type = 'Paren';
   
   	public function __construct($value) {
   		$this->value = $value;
   	}
   
       public function accept($visitor){
   		$this->value = $visitor->visitObj($this->value);
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   		$output->add( '(' );
   		$this->value->genCSS( $output );
   		$output->add( ')' );
   	}
   
   	public function compile($env) {
   		return new Less_Tree_Paren($this->value->compile($env));
   	}
   
   }
    
   
   /**
    * Quoted
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Quoted extends Less_Tree{
   	public $escaped;
   	public $value;
   	public $quote;
   	public $index;
   	public $currentFileInfo;
   	public $type = 'Quoted';
   
   	/**
   	 * @param string $str
   	 */
   	public function __construct($str, $content = '', $escaped = false, $index = false, $currentFileInfo = null ){
   		$this->escaped = $escaped;
   		$this->value = $content;
   		if( $str ){
   			$this->quote = $str[0];
   		}
   		$this->index = $index;
   		$this->currentFileInfo = $currentFileInfo;
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   		if( !$this->escaped ){
   			$output->add( $this->quote, $this->currentFileInfo, $this->index );
           }
           $output->add( $this->value );
           if( !$this->escaped ){
   			$output->add( $this->quote );
           }
       }
   
   	public function compile($env){
   
   		$value = $this->value;
   		if( preg_match_all('/`([^`]+)`/', $this->value, $matches) ){
   			foreach($matches as $i => $match){
   				$js = new Less_Tree_JavaScript($matches[1], $this->index, true);
   				$js = $js->compile()->value;
   				$value = str_replace($matches[0][$i], $js, $value);
   			}
   		}
   
   		if( preg_match_all('/@\{([\w-]+)\}/',$value,$matches) ){
   			foreach($matches[1] as $i => $match){
   				$v = new Less_Tree_Variable('@' . $match, $this->index, $this->currentFileInfo );
   				$v = $v->compile($env);
   				$v = ($v instanceof Less_Tree_Quoted) ? $v->value : $v->toCSS();
   				$value = str_replace($matches[0][$i], $v, $value);
   			}
   		}
   
   		return new Less_Tree_Quoted($this->quote . $value . $this->quote, $value, $this->escaped, $this->index, $this->currentFileInfo);
   	}
   
       public function compare($x) {
   
   		if( !Less_Parser::is_method($x, 'toCSS') ){
   			return -1;
   		}
   
   		$left = $this->toCSS();
   		$right = $x->toCSS();
   
   		if ($left === $right) {
   			return 0;
   		}
   
   		return $left < $right ? -1 : 1;
   	}
   }
    
   
   /**
    * Rule
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Rule extends Less_Tree{
   
   	public $name;
   	public $value;
   	public $important;
   	public $merge;
   	public $index;
   	public $inline;
   	public $variable;
   	public $currentFileInfo;
   	public $type = 'Rule';
   
   	/**
   	 * @param string $important
   	 */
   	public function __construct($name, $value = null, $important = null, $merge = null, $index = null, $currentFileInfo = null,  $inline = false){
   		$this->name = $name;
   		$this->value = ($value instanceof Less_Tree_Value || $value instanceof Less_Tree_Ruleset) ? $value : new Less_Tree_Value(array($value));
   		$this->important = $important ? ' ' . trim($important) : '';
   		$this->merge = $merge;
   		$this->index = $index;
   		$this->currentFileInfo = $currentFileInfo;
   		$this->inline = $inline;
   		$this->variable = ( is_string($name) && $name[0] === '@');
   	}
   
       public function accept($visitor) {
   		$this->value = $visitor->visitObj( $this->value );
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   
   		$output->add( $this->name . Less_Environment::$_outputMap[': '], $this->currentFileInfo, $this->index);
   		try{
   			$this->value->genCSS( $output);
   
   		}catch( Less_Exception_Parser $e ){
   			$e->index = $this->index;
   			$e->currentFile = $this->currentFileInfo;
   			throw $e;
   		}
   		$output->add( $this->important . (($this->inline || (Less_Environment::$lastRule && Less_Parser::$options['compress'])) ? "" : ";"), $this->currentFileInfo, $this->index);
   	}
   
   	public function compile ($env){
   
   		$name = $this->name;
   		if( is_array($name) ){
   			// expand 'primitive' name directly to get
   			// things faster (~10% for benchmark.less):
   			if( count($name) === 1 && $name[0] instanceof Less_Tree_Keyword ){
   				$name = $name[0]->value;
   			}else{
   				$name = $this->CompileName($env,$name);
   			}
   		}
   
   		$strictMathBypass = Less_Parser::$options['strictMath'];
   		if( $name === "font" && !Less_Parser::$options['strictMath'] ){
   			Less_Parser::$options['strictMath'] = true;
   		}
   
   		try {
   			$evaldValue = $this->value->compile($env);
   
   			if( !$this->variable && $evaldValue->type === "DetachedRuleset") {
   				throw new Less_Exception_Compiler("Rulesets cannot be evaluated on a property.", null, $this->index, $this->currentFileInfo);
   			}
   
   			if( Less_Environment::$mixin_stack ){
   				$return = new Less_Tree_Rule($name, $evaldValue, $this->important, $this->merge, $this->index, $this->currentFileInfo, $this->inline);
   			}else{
   				$this->name = $name;
   				$this->value = $evaldValue;
   				$return = $this;
   			}
   
   		}catch( Less_Exception_Parser $e ){
   			if( !is_numeric($e->index) ){
   				$e->index = $this->index;
   				$e->currentFile = $this->currentFileInfo;
   			}
   			throw $e;
   		}
   
   		Less_Parser::$options['strictMath'] = $strictMathBypass;
   
   		return $return;
   	}
   
   
       public function CompileName( $env, $name ){
   		$output = new Less_Output();
   		foreach($name as $n){
   			$n->compile($env)->genCSS($output);
   		}
   		return $output->toString();
   	}
   
       public function makeImportant(){
   		return new Less_Tree_Rule($this->name, $this->value, '!important', $this->merge, $this->index, $this->currentFileInfo, $this->inline);
   	}
   
   }
    
   
   /**
    * Ruleset
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Ruleset extends Less_Tree{
   
   	protected $lookups;
   	public $_variables;
   	public $_rulesets;
   
   	public $strictImports;
   
   	public $selectors;
   	public $rules;
   	public $root;
   	public $allowImports;
   	public $paths;
   	public $firstRoot;
   	public $type = 'Ruleset';
   	public $multiMedia;
   	public $allExtends;
   
   	public $ruleset_id;
   	public $originalRuleset;
   
   	public $first_oelements;
   
   	public function SetRulesetIndex(){
   		$this->ruleset_id = Less_Parser::$next_id++;
   		$this->originalRuleset = $this->ruleset_id;
   
   		if( $this->selectors ){
   			foreach($this->selectors as $sel){
   				if( $sel->_oelements ){
   					$this->first_oelements[$sel->_oelements[0]] = true;
   				}
   			}
   		}
   	}
   
   	public function __construct($selectors, $rules, $strictImports = null){
   		$this->selectors = $selectors;
   		$this->rules = $rules;
   		$this->lookups = array();
   		$this->strictImports = $strictImports;
   		$this->SetRulesetIndex();
   	}
   
   	public function accept( $visitor ){
   		if( $this->paths ){
   			$paths_len = count($this->paths);
   			for($i = 0,$paths_len; $i < $paths_len; $i++ ){
   				$this->paths[$i] = $visitor->visitArray($this->paths[$i]);
   			}
   		}elseif( $this->selectors ){
   			$this->selectors = $visitor->visitArray($this->selectors);
   		}
   
   		if( $this->rules ){
   			$this->rules = $visitor->visitArray($this->rules);
   		}
   	}
   
   	public function compile($env){
   
   		$ruleset = $this->PrepareRuleset($env);
   
   
   		// Store the frames around mixin definitions,
   		// so they can be evaluated like closures when the time comes.
   		$rsRuleCnt = count($ruleset->rules);
   		for( $i = 0; $i < $rsRuleCnt; $i++ ){
   			if( $ruleset->rules[$i] instanceof Less_Tree_Mixin_Definition || $ruleset->rules[$i] instanceof Less_Tree_DetachedRuleset ){
   				$ruleset->rules[$i] = $ruleset->rules[$i]->compile($env);
   			}
   		}
   
   		$mediaBlockCount = 0;
   		if( $env instanceof Less_Environment ){
   			$mediaBlockCount = count($env->mediaBlocks);
   		}
   
   		// Evaluate mixin calls.
   		$this->EvalMixinCalls( $ruleset, $env, $rsRuleCnt );
   
   
   		// Evaluate everything else
   		for( $i=0; $i<$rsRuleCnt; $i++ ){
   			if(! ($ruleset->rules[$i] instanceof Less_Tree_Mixin_Definition || $ruleset->rules[$i] instanceof Less_Tree_DetachedRuleset) ){
   				$ruleset->rules[$i] = $ruleset->rules[$i]->compile($env);
   			}
   		}
   
           // Evaluate everything else
   		for( $i=0; $i<$rsRuleCnt; $i++ ){
   			$rule = $ruleset->rules[$i];
   
               // for rulesets, check if it is a css guard and can be removed
   			if( $rule instanceof Less_Tree_Ruleset && $rule->selectors && count($rule->selectors) === 1 ){
   
                   // check if it can be folded in (e.g. & where)
   				if( $rule->selectors[0]->isJustParentSelector() ){
   					array_splice($ruleset->rules,$i--,1);
   					$rsRuleCnt--;
   
   					for($j = 0; $j < count($rule->rules); $j++ ){
   						$subRule = $rule->rules[$j];
   						if( !($subRule instanceof Less_Tree_Rule) || !$subRule->variable ){
   							array_splice($ruleset->rules, ++$i, 0, array($subRule));
   							$rsRuleCnt++;
   						}
   					}
   
                   }
               }
           }
   
   
   		// Pop the stack
   		$env->shiftFrame();
   
   		if ($mediaBlockCount) {
   			$len = count($env->mediaBlocks);
   			for($i = $mediaBlockCount; $i < $len; $i++ ){
   				$env->mediaBlocks[$i]->bubbleSelectors($ruleset->selectors);
   			}
   		}
   
   		return $ruleset;
   	}
   
   	/**
   	 * Compile Less_Tree_Mixin_Call objects
   	 *
   	 * @param Less_Tree_Ruleset $ruleset
   	 * @param integer $rsRuleCnt
   	 */
   	private function EvalMixinCalls( $ruleset, $env, &$rsRuleCnt ){
   		for($i=0; $i < $rsRuleCnt; $i++){
   			$rule = $ruleset->rules[$i];
   
   			if( $rule instanceof Less_Tree_Mixin_Call ){
   				$rule = $rule->compile($env);
   
   				$temp = array();
   				foreach($rule as $r){
   					if( ($r instanceof Less_Tree_Rule) && $r->variable ){
   						// do not pollute the scope if the variable is
   						// already there. consider returning false here
   						// but we need a way to "return" variable from mixins
   						if( !$ruleset->variable($r->name) ){
   							$temp[] = $r;
   						}
   					}else{
   						$temp[] = $r;
   					}
   				}
   				$temp_count = count($temp)-1;
   				array_splice($ruleset->rules, $i, 1, $temp);
   				$rsRuleCnt += $temp_count;
   				$i += $temp_count;
   				$ruleset->resetCache();
   
   			}elseif( $rule instanceof Less_Tree_RulesetCall ){
   
   				$rule = $rule->compile($env);
   				$rules = array();
   				foreach($rule->rules as $r){
   					if( ($r instanceof Less_Tree_Rule) && $r->variable ){
   						continue;
   					}
   					$rules[] = $r;
   				}
   
   				array_splice($ruleset->rules, $i, 1, $rules);
   				$temp_count = count($rules);
   				$rsRuleCnt += $temp_count - 1;
   				$i += $temp_count-1;
   				$ruleset->resetCache();
   			}
   
   		}
   	}
   
   
   	/**
   	 * Compile the selectors and create a new ruleset object for the compile() method
   	 *
   	 */
   	private function PrepareRuleset($env){
   
   		$hasOnePassingSelector = false;
   		$selectors = array();
   		if( $this->selectors ){
   			Less_Tree_DefaultFunc::error("it is currently only allowed in parametric mixin guards,");
   
   			foreach($this->selectors as $s){
   				$selector = $s->compile($env);
   				$selectors[] = $selector;
   				if( $selector->evaldCondition ){
   					$hasOnePassingSelector = true;
   				}
   			}
   
   			Less_Tree_DefaultFunc::reset();
   		} else {
   			$hasOnePassingSelector = true;
   		}
   
   		if( $this->rules && $hasOnePassingSelector ){
   			$rules = $this->rules;
   		}else{
   			$rules = array();
   		}
   
   		$ruleset = new Less_Tree_Ruleset($selectors, $rules, $this->strictImports);
   
   		$ruleset->originalRuleset = $this->ruleset_id;
   
   		$ruleset->root = $this->root;
   		$ruleset->firstRoot = $this->firstRoot;
   		$ruleset->allowImports = $this->allowImports;
   
   
   		// push the current ruleset to the frames stack
   		$env->unshiftFrame($ruleset);
   
   
   		// Evaluate imports
   		if( $ruleset->root || $ruleset->allowImports || !$ruleset->strictImports ){
   			$ruleset->evalImports($env);
   		}
   
   		return $ruleset;
   	}
   
   	function evalImports($env) {
   
   		$rules_len = count($this->rules);
   		for($i=0; $i < $rules_len; $i++){
   			$rule = $this->rules[$i];
   
   			if( $rule instanceof Less_Tree_Import ){
   				$rules = $rule->compile($env);
   				if( is_array($rules) ){
   					array_splice($this->rules, $i, 1, $rules);
   					$temp_count = count($rules)-1;
   					$i += $temp_count;
   					$rules_len += $temp_count;
   				}else{
   					array_splice($this->rules, $i, 1, array($rules));
   				}
   
   				$this->resetCache();
   			}
   		}
   	}
   
   	function makeImportant(){
   
   		$important_rules = array();
   		foreach($this->rules as $rule){
   			if( $rule instanceof Less_Tree_Rule || $rule instanceof Less_Tree_Ruleset || $rule instanceof Less_Tree_NameValue ){
   				$important_rules[] = $rule->makeImportant();
   			}else{
   				$important_rules[] = $rule;
   			}
   		}
   
   		return new Less_Tree_Ruleset($this->selectors, $important_rules, $this->strictImports );
   	}
   
   	public function matchArgs($args){
   		return !$args;
   	}
   
   	// lets you call a css selector with a guard
   	public function matchCondition( $args, $env ){
   		$lastSelector = end($this->selectors);
   
   		if( !$lastSelector->evaldCondition ){
   			return false;
   		}
   		if( $lastSelector->condition && !$lastSelector->condition->compile( $env->copyEvalEnv( $env->frames ) ) ){
   			return false;
   		}
   		return true;
   	}
   
   	function resetCache(){
   		$this->_rulesets = null;
   		$this->_variables = null;
   		$this->lookups = array();
   	}
   
   	public function variables(){
   		$this->_variables = array();
   		foreach( $this->rules as $r){
   			if ($r instanceof Less_Tree_Rule && $r->variable === true) {
   				$this->_variables[$r->name] = $r;
   			}
   		}
   	}
   
   	public function variable($name){
   
   		if( is_null($this->_variables) ){
   			$this->variables();
   		}
   		return isset($this->_variables[$name]) ? $this->_variables[$name] : null;
   	}
   
   	public function find( $selector, $self = null ){
   
   		$key = implode(' ',$selector->_oelements);
   
   		if( !isset($this->lookups[$key]) ){
   
   			if( !$self ){
   				$self = $this->ruleset_id;
   			}
   
   			$this->lookups[$key] = array();
   
   			$first_oelement = $selector->_oelements[0];
   
   			foreach($this->rules as $rule){
   				if( $rule instanceof Less_Tree_Ruleset && $rule->ruleset_id != $self ){
   
   					if( isset($rule->first_oelements[$first_oelement]) ){
   
   						foreach( $rule->selectors as $ruleSelector ){
   							$match = $selector->match($ruleSelector);
   							if( $match ){
   								if( $selector->elements_len > $match ){
   									$this->lookups[$key] = array_merge($this->lookups[$key], $rule->find( new Less_Tree_Selector(array_slice($selector->elements, $match)), $self));
   								} else {
   									$this->lookups[$key][] = $rule;
   								}
   								break;
   							}
   						}
   					}
   				}
   			}
   		}
   
   		return $this->lookups[$key];
   	}
   
   
   	/**
   	 * @see Less_Tree::genCSS
   	 */
   	public function genCSS( $output ){
   
   		if( !$this->root ){
   			Less_Environment::$tabLevel++;
   		}
   
   		$tabRuleStr = $tabSetStr = '';
   		if( !Less_Parser::$options['compress'] ){
   			if( Less_Environment::$tabLevel ){
   				$tabRuleStr = "\n".str_repeat( Less_Parser::$options['indentation'] , Less_Environment::$tabLevel );
   				$tabSetStr = "\n".str_repeat( Less_Parser::$options['indentation'] , Less_Environment::$tabLevel-1 );
   			}else{
   				$tabSetStr = $tabRuleStr = "\n";
   			}
   		}
   
   
   		$ruleNodes = array();
   		$rulesetNodes = array();
   		foreach($this->rules as $rule){
   
   			$class = get_class($rule);
   			if( ($class === 'Less_Tree_Media') || ($class === 'Less_Tree_Directive') || ($this->root && $class === 'Less_Tree_Comment') || ($class === 'Less_Tree_Ruleset' && $rule->rules) ){
   				$rulesetNodes[] = $rule;
   			}else{
   				$ruleNodes[] = $rule;
   			}
   		}
   
   		// If this is the root node, we don't render
   		// a selector, or {}.
   		if( !$this->root ){
   
   			/*
   			debugInfo = tree.debugInfo(env, this, tabSetStr);
   
   			if (debugInfo) {
   				output.add(debugInfo);
   				output.add(tabSetStr);
   			}
   			*/
   
   			$paths_len = count($this->paths);
   			for( $i = 0; $i < $paths_len; $i++ ){
   				$path = $this->paths[$i];
   				$firstSelector = true;
   
   				foreach($path as $p){
   					$p->genCSS( $output, $firstSelector );
   					$firstSelector = false;
   				}
   
   				if( $i + 1 < $paths_len ){
   					$output->add( ',' . $tabSetStr );
   				}
   			}
   
   			$output->add( (Less_Parser::$options['compress'] ? '{' : " {") . $tabRuleStr );
   		}
   
   		// Compile rules and rulesets
   		$ruleNodes_len = count($ruleNodes);
   		$rulesetNodes_len = count($rulesetNodes);
   		for( $i = 0; $i < $ruleNodes_len; $i++ ){
   			$rule = $ruleNodes[$i];
   
   			// @page{ directive ends up with root elements inside it, a mix of rules and rulesets
   			// In this instance we do not know whether it is the last property
   			if( $i + 1 === $ruleNodes_len && (!$this->root || $rulesetNodes_len === 0 || $this->firstRoot ) ){
   				Less_Environment::$lastRule = true;
   			}
   
   			$rule->genCSS( $output );
   
   			if( !Less_Environment::$lastRule ){
   				$output->add( $tabRuleStr );
   			}else{
   				Less_Environment::$lastRule = false;
   			}
   		}
   
   		if( !$this->root ){
   			$output->add( $tabSetStr . '}' );
   			Less_Environment::$tabLevel--;
   		}
   
   		$firstRuleset = true;
   		$space = ($this->root ? $tabRuleStr : $tabSetStr);
   		for( $i = 0; $i < $rulesetNodes_len; $i++ ){
   
   			if( $ruleNodes_len && $firstRuleset ){
   				$output->add( $space );
   			}elseif( !$firstRuleset ){
   				$output->add( $space );
   			}
   			$firstRuleset = false;
   			$rulesetNodes[$i]->genCSS( $output);
   		}
   
   		if( !Less_Parser::$options['compress'] && $this->firstRoot ){
   			$output->add( "\n" );
   		}
   
   	}
   
   
   	function markReferenced(){
   		if( !$this->selectors ){
   			return;
   		}
   		foreach($this->selectors as $selector){
   			$selector->markReferenced();
   		}
   	}
   
   	public function joinSelectors( $context, $selectors ){
   		$paths = array();
   		if( is_array($selectors) ){
   			foreach($selectors as $selector) {
   				$this->joinSelector( $paths, $context, $selector);
   			}
   		}
   		return $paths;
   	}
   
   	public function joinSelector( &$paths, $context, $selector){
   
   		$hasParentSelector = false;
   
   		foreach($selector->elements as $el) {
   			if( $el->value === '&') {
   				$hasParentSelector = true;
   			}
   		}
   
   		if( !$hasParentSelector ){
   			if( $context ){
   				foreach($context as $context_el){
   					$paths[] = array_merge($context_el, array($selector) );
   				}
   			}else {
   				$paths[] = array($selector);
   			}
   			return;
   		}
   
   
   		// The paths are [[Selector]]
   		// The first list is a list of comma seperated selectors
   		// The inner list is a list of inheritance seperated selectors
   		// e.g.
   		// .a, .b {
   		//   .c {
   		//   }
   		// }
   		// == [[.a] [.c]] [[.b] [.c]]
   		//
   
   		// the elements from the current selector so far
   		$currentElements = array();
   		// the current list of new selectors to add to the path.
   		// We will build it up. We initiate it with one empty selector as we "multiply" the new selectors
   		// by the parents
   		$newSelectors = array(array());
   
   
   		foreach( $selector->elements as $el){
   
   			// non parent reference elements just get added
   			if( $el->value !== '&' ){
   				$currentElements[] = $el;
   			} else {
   				// the new list of selectors to add
   				$selectorsMultiplied = array();
   
   				// merge the current list of non parent selector elements
   				// on to the current list of selectors to add
   				if( $currentElements ){
   					$this->mergeElementsOnToSelectors( $currentElements, $newSelectors);
   				}
   
   				// loop through our current selectors
   				foreach($newSelectors as $sel){
   
   					// if we don't have any parent paths, the & might be in a mixin so that it can be used
   					// whether there are parents or not
   					if( !$context ){
   						// the combinator used on el should now be applied to the next element instead so that
   						// it is not lost
   						if( $sel ){
   							$sel[0]->elements = array_slice($sel[0]->elements,0);
   							$sel[0]->elements[] = new Less_Tree_Element($el->combinator, '', $el->index, $el->currentFileInfo );
   						}
   						$selectorsMultiplied[] = $sel;
   					}else {
   
   						// and the parent selectors
   						foreach($context as $parentSel){
   							// We need to put the current selectors
   							// then join the last selector's elements on to the parents selectors
   
   							// our new selector path
   							$newSelectorPath = array();
   							// selectors from the parent after the join
   							$afterParentJoin = array();
   							$newJoinedSelectorEmpty = true;
   
   							//construct the joined selector - if & is the first thing this will be empty,
   							// if not newJoinedSelector will be the last set of elements in the selector
   							if( $sel ){
   								$newSelectorPath = $sel;
   								$lastSelector = array_pop($newSelectorPath);
   								$newJoinedSelector = $selector->createDerived( array_slice($lastSelector->elements,0) );
   								$newJoinedSelectorEmpty = false;
   							}
   							else {
   								$newJoinedSelector = $selector->createDerived(array());
   							}
   
   							//put together the parent selectors after the join
   							if ( count($parentSel) > 1) {
   								$afterParentJoin = array_merge($afterParentJoin, array_slice($parentSel,1) );
   							}
   
   							if ( $parentSel ){
   								$newJoinedSelectorEmpty = false;
   
   								// join the elements so far with the first part of the parent
   								$newJoinedSelector->elements[] = new Less_Tree_Element( $el->combinator, $parentSel[0]->elements[0]->value, $el->index, $el->currentFileInfo);
   
   								$newJoinedSelector->elements = array_merge( $newJoinedSelector->elements, array_slice($parentSel[0]->elements, 1) );
   							}
   
   							if (!$newJoinedSelectorEmpty) {
   								// now add the joined selector
   								$newSelectorPath[] = $newJoinedSelector;
   							}
   
   							// and the rest of the parent
   							$newSelectorPath = array_merge($newSelectorPath, $afterParentJoin);
   
   							// add that to our new set of selectors
   							$selectorsMultiplied[] = $newSelectorPath;
   						}
   					}
   				}
   
   				// our new selectors has been multiplied, so reset the state
   				$newSelectors = $selectorsMultiplied;
   				$currentElements = array();
   			}
   		}
   
   		// if we have any elements left over (e.g. .a& .b == .b)
   		// add them on to all the current selectors
   		if( $currentElements ){
   			$this->mergeElementsOnToSelectors($currentElements, $newSelectors);
   		}
   		foreach( $newSelectors as $new_sel){
   			if( $new_sel ){
   				$paths[] = $new_sel;
   			}
   		}
   	}
   
   	function mergeElementsOnToSelectors( $elements, &$selectors){
   
   		if( !$selectors ){
   			$selectors[] = array( new Less_Tree_Selector($elements) );
   			return;
   		}
   
   
   		foreach( $selectors as &$sel){
   
   			// if the previous thing in sel is a parent this needs to join on to it
   			if( $sel ){
   				$last = count($sel)-1;
   				$sel[$last] = $sel[$last]->createDerived( array_merge($sel[$last]->elements, $elements) );
   			}else{
   				$sel[] = new Less_Tree_Selector( $elements );
   			}
   		}
   	}
   }
    
   
   /**
    * RulesetCall
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_RulesetCall extends Less_Tree{
   
   	public $variable;
   	public $type = "RulesetCall";
   
       public function __construct($variable){
   		$this->variable = $variable;
   	}
   
       public function accept($visitor) {}
   
       public function compile( $env ){
   		$variable = new Less_Tree_Variable($this->variable);
   		$detachedRuleset = $variable->compile($env);
   		return $detachedRuleset->callEval($env);
   	}
   }
   
    
   
   /**
    * Selector
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Selector extends Less_Tree{
   
   	public $elements;
   	public $condition;
   	public $extendList = array();
   	public $_css;
   	public $index;
   	public $evaldCondition = false;
   	public $type = 'Selector';
   	public $currentFileInfo = array();
   	public $isReferenced;
   	public $mediaEmpty;
   
   	public $elements_len = 0;
   
   	public $_oelements;
   	public $_oelements_len;
   	public $cacheable = true;
   
   	/**
   	 * @param boolean $isReferenced
   	 */
   	public function __construct( $elements, $extendList = array() , $condition = null, $index=null, $currentFileInfo=null, $isReferenced=null ){
   
   		$this->elements = $elements;
   		$this->elements_len = count($elements);
   		$this->extendList = $extendList;
   		$this->condition = $condition;
   		if( $currentFileInfo ){
   			$this->currentFileInfo = $currentFileInfo;
   		}
   		$this->isReferenced = $isReferenced;
   		if( !$condition ){
   			$this->evaldCondition = true;
   		}
   
   		$this->CacheElements();
   	}
   
       public function accept($visitor) {
   		$this->elements = $visitor->visitArray($this->elements);
   		$this->extendList = $visitor->visitArray($this->extendList);
   		if( $this->condition ){
   			$this->condition = $visitor->visitObj($this->condition);
   		}
   
   		if( $visitor instanceof Less_Visitor_extendFinder ){
   			$this->CacheElements();
   		}
   	}
   
       public function createDerived( $elements, $extendList = null, $evaldCondition = null ){
   		$newSelector = new Less_Tree_Selector( $elements, ($extendList ? $extendList : $this->extendList), null, $this->index, $this->currentFileInfo, $this->isReferenced);
   		$newSelector->evaldCondition = $evaldCondition ? $evaldCondition : $this->evaldCondition;
   		return $newSelector;
   	}
   
   
   	public function match( $other ){
   
   		if( !$other->_oelements || ($this->elements_len < $other->_oelements_len) ){
   			return 0;
   		}
   
   		for( $i = 0; $i < $other->_oelements_len; $i++ ){
   			if( $this->elements[$i]->value !== $other->_oelements[$i]) {
   				return 0;
   			}
   		}
   
   		return $other->_oelements_len; // return number of matched elements
   	}
   
   
   	public function CacheElements(){
   
   		$this->_oelements = array();
   		$css = '';
   
   		foreach($this->elements as $v){
   
   			$css .= $v->combinator;
   			if( !$v->value_is_object ){
   				$css .= $v->value;
   				continue;
   			}
   
   			if( !property_exists($v->value,'value') || !is_string($v->value->value) ){
   				$this->cacheable = false;
   				return;
   			}
   			$css .= $v->value->value;
   		}
   
   		$this->_oelements_len = preg_match_all('/[,&#\.\w-](?:[\w-]|(?:\\\\.))*/', $css, $matches);
   		if( $this->_oelements_len ){
   			$this->_oelements = $matches[0];
   
   			if( $this->_oelements[0] === '&' ){
   				array_shift($this->_oelements);
   				$this->_oelements_len--;
   			}
   		}
   	}
   
   	public function isJustParentSelector(){
   		return !$this->mediaEmpty &&
   			count($this->elements) === 1 &&
   			$this->elements[0]->value === '&' &&
   			($this->elements[0]->combinator === ' ' || $this->elements[0]->combinator === '');
   	}
   
   	public function compile($env) {
   
   		$elements = array();
   		foreach($this->elements as $el){
   			$elements[] = $el->compile($env);
   		}
   
   		$extendList = array();
   		foreach($this->extendList as $el){
   			$extendList[] = $el->compile($el);
   		}
   
   		$evaldCondition = false;
   		if( $this->condition ){
   			$evaldCondition = $this->condition->compile($env);
   		}
   
   		return $this->createDerived( $elements, $extendList, $evaldCondition );
   	}
   
   
   	/**
   	 * @see Less_Tree::genCSS
   	 */
       public function genCSS( $output, $firstSelector = true ){
   
   		if( !$firstSelector && $this->elements[0]->combinator === "" ){
   			$output->add(' ', $this->currentFileInfo, $this->index);
   		}
   
   		foreach($this->elements as $element){
   			$element->genCSS( $output );
   		}
   	}
   
       public function markReferenced(){
   		$this->isReferenced = true;
   	}
   
       public function getIsReferenced(){
   		return !isset($this->currentFileInfo['reference']) || !$this->currentFileInfo['reference'] || $this->isReferenced;
   	}
   
       public function getIsOutput(){
   		return $this->evaldCondition;
   	}
   
   }
    
   
   /**
    * UnicodeDescriptor
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_UnicodeDescriptor extends Less_Tree{
   
   	public $value;
   	public $type = 'UnicodeDescriptor';
   
   	public function __construct($value){
   		$this->value = $value;
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
   	public function genCSS( $output ){
   		$output->add( $this->value );
   	}
   
   	public function compile(){
   		return $this;
   	}
   }
   
    
   
   /**
    * Unit
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Unit extends Less_Tree{
   
   	var $numerator = array();
   	var $denominator = array();
   	public $backupUnit;
   	public $type = 'Unit';
   
       public function __construct($numerator = array(), $denominator = array(), $backupUnit = null ){
   		$this->numerator = $numerator;
   		$this->denominator = $denominator;
   		$this->backupUnit = $backupUnit;
   	}
   
       public function __clone(){
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   
   		if( $this->numerator ){
   			$output->add( $this->numerator[0] );
   		}elseif( $this->denominator ){
   			$output->add( $this->denominator[0] );
   		}elseif( !Less_Parser::$options['strictUnits'] && $this->backupUnit ){
   			$output->add( $this->backupUnit );
   			return ;
   		}
   	}
   
       public function toString(){
   		$returnStr = implode('*',$this->numerator);
   		foreach($this->denominator as $d){
   			$returnStr .= '/'.$d;
   		}
   		return $returnStr;
   	}
   
       public function __toString(){
   		return $this->toString();
   	}
   
   
   	/**
   	 * @param Less_Tree_Unit $other
   	 */
       public function compare($other) {
   		return $this->is( $other->toString() ) ? 0 : -1;
   	}
   
       public function is($unitString){
   		return $this->toString() === $unitString;
   	}
   
       public function isLength(){
   		$css = $this->toCSS();
   		return !!preg_match('/px|em|%|in|cm|mm|pc|pt|ex/',$css);
   	}
   
       public function isAngle() {
   		return isset( Less_Tree_UnitConversions::$angle[$this->toCSS()] );
   	}
   
       public function isEmpty(){
   		return !$this->numerator && !$this->denominator;
   	}
   
       public function isSingular() {
   		return count($this->numerator) <= 1 && !$this->denominator;
   	}
   
   
       public function usedUnits(){
   		$result = array();
   
   		foreach(Less_Tree_UnitConversions::$groups as $groupName){
   			$group = Less_Tree_UnitConversions::${$groupName};
   
   			foreach($this->numerator as $atomicUnit){
   				if( isset($group[$atomicUnit]) && !isset($result[$groupName]) ){
   					$result[$groupName] = $atomicUnit;
   				}
   			}
   
   			foreach($this->denominator as $atomicUnit){
   				if( isset($group[$atomicUnit]) && !isset($result[$groupName]) ){
   					$result[$groupName] = $atomicUnit;
   				}
   			}
   		}
   
   		return $result;
   	}
   
       public function cancel(){
   		$counter = array();
   		$backup = null;
   
   		foreach($this->numerator as $atomicUnit){
   			if( !$backup ){
   				$backup = $atomicUnit;
   			}
   			$counter[$atomicUnit] = ( isset($counter[$atomicUnit]) ? $counter[$atomicUnit] : 0) + 1;
   		}
   
   		foreach($this->denominator as $atomicUnit){
   			if( !$backup ){
   				$backup = $atomicUnit;
   			}
   			$counter[$atomicUnit] = ( isset($counter[$atomicUnit]) ? $counter[$atomicUnit] : 0) - 1;
   		}
   
   		$this->numerator = array();
   		$this->denominator = array();
   
   		foreach($counter as $atomicUnit => $count){
   			if( $count > 0 ){
   				for( $i = 0; $i < $count; $i++ ){
   					$this->numerator[] = $atomicUnit;
   				}
   			}elseif( $count < 0 ){
   				for( $i = 0; $i < -$count; $i++ ){
   					$this->denominator[] = $atomicUnit;
   				}
   			}
   		}
   
   		if( !$this->numerator && !$this->denominator && $backup ){
   			$this->backupUnit = $backup;
   		}
   
   		sort($this->numerator);
   		sort($this->denominator);
   	}
   
   
   }
   
    
   
   /**
    * UnitConversions
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_UnitConversions{
   
   	public static $groups = array('length','duration','angle');
   
   	public static $length = array(
   		'm'=> 1,
   		'cm'=> 0.01,
   		'mm'=> 0.001,
   		'in'=> 0.0254,
   		'px'=> 0.000264583, // 0.0254 / 96,
   		'pt'=> 0.000352778, // 0.0254 / 72,
   		'pc'=> 0.004233333, // 0.0254 / 72 * 12
   		);
   
   	public static $duration = array(
   		's'=> 1,
   		'ms'=> 0.001
   		);
   
   	public static $angle = array(
   		'rad' => 0.1591549430919,	// 1/(2*M_PI),
   		'deg' => 0.002777778, 		// 1/360,
   		'grad'=> 0.0025,			// 1/400,
   		'turn'=> 1
   		);
   
   } 
   
   /**
    * Url
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Url extends Less_Tree{
   
   	public $attrs;
   	public $value;
   	public $currentFileInfo;
   	public $isEvald;
   	public $type = 'Url';
   
   	public function __construct($value, $currentFileInfo = null, $isEvald = null){
   		$this->value = $value;
   		$this->currentFileInfo = $currentFileInfo;
   		$this->isEvald = $isEvald;
   	}
   
       public function accept( $visitor ){
   		$this->value = $visitor->visitObj($this->value);
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
       public function genCSS( $output ){
   		$output->add( 'url(' );
   		$this->value->genCSS( $output );
   		$output->add( ')' );
   	}
   
   	/**
   	 * @param Less_Functions $ctx
   	 */
   	public function compile($ctx){
   		$val = $this->value->compile($ctx);
   
   		if( !$this->isEvald ){
   			// Add the base path if the URL is relative
   			if( Less_Parser::$options['relativeUrls']
   				&& $this->currentFileInfo
   				&& is_string($val->value)
   				&& Less_Environment::isPathRelative($val->value)
   			){
   				$rootpath = $this->currentFileInfo['uri_root'];
   				if ( !$val->quote ){
   					$rootpath = preg_replace('/[\(\)\'"\s]/', '\\$1', $rootpath );
   				}
   				$val->value = $rootpath . $val->value;
   			}
   
   			$val->value = Less_Environment::normalizePath( $val->value);
   		}
   
   		// Add cache buster if enabled
   		if( Less_Parser::$options['urlArgs'] ){
   			if( !preg_match('/^\s*data:/',$val->value) ){
   				$delimiter = strpos($val->value,'?') === false ? '?' : '&';
   				$urlArgs = $delimiter . Less_Parser::$options['urlArgs'];
   				$hash_pos = strpos($val->value,'#');
   				if( $hash_pos !== false ){
   					$val->value = substr_replace($val->value,$urlArgs, $hash_pos, 0);
   				} else {
   					$val->value .= $urlArgs;
   				}
   			}
   		}
   
   		return new Less_Tree_URL($val, $this->currentFileInfo, true);
   	}
   
   }
    
   
   /**
    * Value
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Value extends Less_Tree{
   
   	public $type = 'Value';
   	public $value;
   
   	public function __construct($value){
   		$this->value = $value;
   	}
   
       public function accept($visitor) {
   		$this->value = $visitor->visitArray($this->value);
   	}
   
   	public function compile($env){
   
   		$ret = array();
   		$i = 0;
   		foreach($this->value as $i => $v){
   			$ret[] = $v->compile($env);
   		}
   		if( $i > 0 ){
   			return new Less_Tree_Value($ret);
   		}
   		return $ret[0];
   	}
   
       /**
        * @see Less_Tree::genCSS
        */
   	function genCSS( $output ){
   		$len = count($this->value);
   		for($i = 0; $i < $len; $i++ ){
   			$this->value[$i]->genCSS( $output );
   			if( $i+1 < $len ){
   				$output->add( Less_Environment::$_outputMap[','] );
   			}
   		}
   	}
   
   }
    
   
   /**
    * Variable
    *
    * @package Less
    * @subpackage tree
    */
   class Less_Tree_Variable extends Less_Tree{
   
   	public $name;
   	public $index;
   	public $currentFileInfo;
   	public $evaluating = false;
   	public $type = 'Variable';
   
       /**
        * @param string $name
        */
       public function __construct($name, $index = null, $currentFileInfo = null) {
           $this->name = $name;
           $this->index = $index;
   		$this->currentFileInfo = $currentFileInfo;
       }
   
   	public function compile($env) {
   
   		if( $this->name[1] === '@' ){
   			$v = new Less_Tree_Variable(substr($this->name, 1), $this->index + 1, $this->currentFileInfo);
   			$name = '@' . $v->compile($env)->value;
   		}else{
   			$name = $this->name;
   		}
   
   		if ($this->evaluating) {
   			throw new Less_Exception_Compiler("Recursive variable definition for " . $name, null, $this->index, $this->currentFileInfo);
   		}
   
   		$this->evaluating = true;
   
   		foreach($env->frames as $frame){
   			if( $v = $frame->variable($name) ){
   				$r = $v->value->compile($env);
   				$this->evaluating = false;
   				return $r;
   			}
   		}
   
   		throw new Less_Exception_Compiler("variable " . $name . " is undefined in file ".$this->currentFileInfo["filename"], null, $this->index, $this->currentFileInfo);
   	}
   
   }
    
   
   
   class Less_Tree_Mixin_Call extends Less_Tree{
   
   	public $selector;
   	public $arguments;
   	public $index;
   	public $currentFileInfo;
   
   	public $important;
   	public $type = 'MixinCall';
   
   	/**
   	 * less.js: tree.mixin.Call
   	 *
   	 */
   	public function __construct($elements, $args, $index, $currentFileInfo, $important = false){
   		$this->selector = new Less_Tree_Selector($elements);
   		$this->arguments = $args;
   		$this->index = $index;
   		$this->currentFileInfo = $currentFileInfo;
   		$this->important = $important;
   	}
   
   	//function accept($visitor){
   	//	$this->selector = $visitor->visit($this->selector);
   	//	$this->arguments = $visitor->visit($this->arguments);
   	//}
   
   
   	public function compile($env){
   
   		$rules = array();
   		$match = false;
   		$isOneFound = false;
   		$candidates = array();
   		$defaultUsed = false;
   		$conditionResult = array();
   
   		$args = array();
   		foreach($this->arguments as $a){
   			$args[] = array('name'=> $a['name'], 'value' => $a['value']->compile($env) );
   		}
   
   		foreach($env->frames as $frame){
   
   			$mixins = $frame->find($this->selector);
   
   			if( !$mixins ){
   				continue;
   			}
   
   			$isOneFound = true;
   			$defNone = 0;
   			$defTrue = 1;
   			$defFalse = 2;
   
   			// To make `default()` function independent of definition order we have two "subpasses" here.
   			// At first we evaluate each guard *twice* (with `default() == true` and `default() == false`),
   			// and build candidate list with corresponding flags. Then, when we know all possible matches,
   			// we make a final decision.
   
   			$mixins_len = count($mixins);
   			for( $m = 0; $m < $mixins_len; $m++ ){
   				$mixin = $mixins[$m];
   
   				if( $this->IsRecursive( $env, $mixin ) ){
   					continue;
   				}
   
   				if( $mixin->matchArgs($args, $env) ){
   
   					$candidate = array('mixin' => $mixin, 'group' => $defNone);
   
   					if( $mixin instanceof Less_Tree_Ruleset ){
   
   						for( $f = 0; $f < 2; $f++ ){
   							Less_Tree_DefaultFunc::value($f);
   							$conditionResult[$f] = $mixin->matchCondition( $args, $env);
   						}
   						if( $conditionResult[0] || $conditionResult[1] ){
   							if( $conditionResult[0] != $conditionResult[1] ){
   								$candidate['group'] = $conditionResult[1] ? $defTrue : $defFalse;
   							}
   
   							$candidates[] = $candidate;
   						}
   					}else{
   						$candidates[] = $candidate;
   					}
   
   					$match = true;
   				}
   			}
   
   			Less_Tree_DefaultFunc::reset();
   
   
   			$count = array(0, 0, 0);
   			for( $m = 0; $m < count($candidates); $m++ ){
   				$count[ $candidates[$m]['group'] ]++;
   			}
   
   			if( $count[$defNone] > 0 ){
   				$defaultResult = $defFalse;
   			} else {
   				$defaultResult = $defTrue;
   				if( ($count[$defTrue] + $count[$defFalse]) > 1 ){
   					throw new Exception( 'Ambiguous use of `default()` found when matching for `' . $this->format($args) . '`' );
   				}
   			}
   
   
   			$candidates_length = count($candidates);
   			$length_1 = ($candidates_length == 1);
   
   			for( $m = 0; $m < $candidates_length; $m++){
   				$candidate = $candidates[$m]['group'];
   				if( ($candidate === $defNone) || ($candidate === $defaultResult) ){
   					try{
   						$mixin = $candidates[$m]['mixin'];
   						if( !($mixin instanceof Less_Tree_Mixin_Definition) ){
   							$mixin = new Less_Tree_Mixin_Definition('', array(), $mixin->rules, null, false);
   							$mixin->originalRuleset = $mixins[$m]->originalRuleset;
   						}
   						$rules = array_merge($rules, $mixin->evalCall($env, $args, $this->important)->rules);
   					} catch (Exception $e) {
   						//throw new Less_Exception_Compiler($e->getMessage(), $e->index, null, $this->currentFileInfo['filename']);
   						throw new Less_Exception_Compiler($e->getMessage(), null, null, $this->currentFileInfo);
   					}
   				}
   			}
   
   			if( $match ){
   				if( !$this->currentFileInfo || !isset($this->currentFileInfo['reference']) || !$this->currentFileInfo['reference'] ){
   					Less_Tree::ReferencedArray($rules);
   				}
   
   				return $rules;
   			}
   		}
   
   		if( $isOneFound ){
   			throw new Less_Exception_Compiler('No matching definition was found for `'.$this->Format( $args ).'`', null, $this->index, $this->currentFileInfo);
   
   		}else{
   			throw new Less_Exception_Compiler(trim($this->selector->toCSS()) . " is undefined in ".$this->currentFileInfo['filename'], null, $this->index);
   		}
   
   	}
   
   	/**
   	 * Format the args for use in exception messages
   	 *
   	 */
   	private function Format($args){
   		$message = array();
   		if( $args ){
   			foreach($args as $a){
   				$argValue = '';
   				if( $a['name'] ){
   					$argValue .= $a['name'] . ':';
   				}
   				if( is_object($a['value']) ){
   					$argValue .= $a['value']->toCSS();
   				}else{
   					$argValue .= '???';
   				}
   				$message[] = $argValue;
   			}
   		}
   		return implode(', ',$message);
   	}
   
   
   	/**
   	 * Are we in a recursive mixin call?
   	 *
   	 * @return bool
   	 */
   	private function IsRecursive( $env, $mixin ){
   
   		foreach($env->frames as $recur_frame){
   			if( !($mixin instanceof Less_Tree_Mixin_Definition) ){
   
   				if( $mixin === $recur_frame ){
   					return true;
   				}
   
   				if( isset($recur_frame->originalRuleset) && $mixin->ruleset_id === $recur_frame->originalRuleset ){
   					return true;
   				}
   			}
   		}
   
   		return false;
   	}
   
   }
   
   
    
   
   class Less_Tree_Mixin_Definition extends Less_Tree_Ruleset{
   	public $name;
   	public $selectors;
   	public $params;
   	public $arity		= 0;
   	public $rules;
   	public $lookups		= array();
   	public $required	= 0;
   	public $frames		= array();
   	public $condition;
   	public $variadic;
   	public $type		= 'MixinDefinition';
   
   
   	// less.js : /lib/less/tree/mixin.js : tree.mixin.Definition
   	public function __construct($name, $params, $rules, $condition, $variadic = false, $frames = array() ){
   		$this->name = $name;
   		$this->selectors = array(new Less_Tree_Selector(array( new Less_Tree_Element(null, $name))));
   
   		$this->params = $params;
   		$this->condition = $condition;
   		$this->variadic = $variadic;
   		$this->rules = $rules;
   
   		if( $params ){
   			$this->arity = count($params);
   			foreach( $params as $p ){
   				if (! isset($p['name']) || ($p['name'] && !isset($p['value']))) {
   					$this->required++;
   				}
   			}
   		}
   
   		$this->frames = $frames;
   		$this->SetRulesetIndex();
   	}
   
   
   
   	//function accept( $visitor ){
   	//	$this->params = $visitor->visit($this->params);
   	//	$this->rules = $visitor->visit($this->rules);
   	//	$this->condition = $visitor->visit($this->condition);
   	//}
   
   
   	public function toCSS(){
   		return '';
   	}
   
   	// less.js : /lib/less/tree/mixin.js : tree.mixin.Definition.evalParams
   	public function compileParams($env, $mixinFrames, $args = array() , &$evaldArguments = array() ){
   		$frame = new Less_Tree_Ruleset(null, array());
   		$params = $this->params;
   		$mixinEnv = null;
   		$argsLength = 0;
   
   		if( $args ){
   			$argsLength = count($args);
   			for($i = 0; $i < $argsLength; $i++ ){
   				$arg = $args[$i];
   
   				if( $arg && $arg['name'] ){
   					$isNamedFound = false;
   
   					foreach($params as $j => $param){
   						if( !isset($evaldArguments[$j]) && $arg['name'] === $params[$j]['name']) {
   							$evaldArguments[$j] = $arg['value']->compile($env);
   							array_unshift($frame->rules, new Less_Tree_Rule( $arg['name'], $arg['value']->compile($env) ) );
   							$isNamedFound = true;
   							break;
   						}
   					}
   					if ($isNamedFound) {
   						array_splice($args, $i, 1);
   						$i--;
   						$argsLength--;
   						continue;
   					} else {
   						throw new Less_Exception_Compiler("Named argument for " . $this->name .' '.$args[$i]['name'] . ' not found');
   					}
   				}
   			}
   		}
   
   		$argIndex = 0;
   		foreach($params as $i => $param){
   
   			if ( isset($evaldArguments[$i]) ){ continue; }
   
   			$arg = null;
   			if( isset($args[$argIndex]) ){
   				$arg = $args[$argIndex];
   			}
   
   			if (isset($param['name']) && $param['name']) {
   
   				if( isset($param['variadic']) ){
   					$varargs = array();
   					for ($j = $argIndex; $j < $argsLength; $j++) {
   						$varargs[] = $args[$j]['value']->compile($env);
   					}
   					$expression = new Less_Tree_Expression($varargs);
   					array_unshift($frame->rules, new Less_Tree_Rule($param['name'], $expression->compile($env)));
   				}else{
   					$val = ($arg && $arg['value']) ? $arg['value'] : false;
   
   					if ($val) {
   						$val = $val->compile($env);
   					} else if ( isset($param['value']) ) {
   
   						if( !$mixinEnv ){
   							$mixinEnv = new Less_Environment();
   							$mixinEnv->frames = array_merge( array($frame), $mixinFrames);
   						}
   
   						$val = $param['value']->compile($mixinEnv);
   						$frame->resetCache();
   					} else {
   						throw new Less_Exception_Compiler("Wrong number of arguments for " . $this->name . " (" . $argsLength . ' for ' . $this->arity . ")");
   					}
   
   					array_unshift($frame->rules, new Less_Tree_Rule($param['name'], $val));
   					$evaldArguments[$i] = $val;
   				}
   			}
   
   			if ( isset($param['variadic']) && $args) {
   				for ($j = $argIndex; $j < $argsLength; $j++) {
   					$evaldArguments[$j] = $args[$j]['value']->compile($env);
   				}
   			}
   			$argIndex++;
   		}
   
   		ksort($evaldArguments);
   		$evaldArguments = array_values($evaldArguments);
   
   		return $frame;
   	}
   
   	public function compile($env) {
   		if( $this->frames ){
   			return new Less_Tree_Mixin_Definition($this->name, $this->params, $this->rules, $this->condition, $this->variadic, $this->frames );
   		}
   		return new Less_Tree_Mixin_Definition($this->name, $this->params, $this->rules, $this->condition, $this->variadic, $env->frames );
   	}
   
   	public function evalCall($env, $args = NULL, $important = NULL) {
   
   		Less_Environment::$mixin_stack++;
   
   		$_arguments = array();
   
   		if( $this->frames ){
   			$mixinFrames = array_merge($this->frames, $env->frames);
   		}else{
   			$mixinFrames = $env->frames;
   		}
   
   		$frame = $this->compileParams($env, $mixinFrames, $args, $_arguments);
   
   		$ex = new Less_Tree_Expression($_arguments);
   		array_unshift($frame->rules, new Less_Tree_Rule('@arguments', $ex->compile($env)));
   
   
   		$ruleset = new Less_Tree_Ruleset(null, $this->rules);
   		$ruleset->originalRuleset = $this->ruleset_id;
   
   
   		$ruleSetEnv = new Less_Environment();
   		$ruleSetEnv->frames = array_merge( array($this, $frame), $mixinFrames );
   		$ruleset = $ruleset->compile( $ruleSetEnv );
   
   		if( $important ){
   			$ruleset = $ruleset->makeImportant();
   		}
   
   		Less_Environment::$mixin_stack--;
   
   		return $ruleset;
   	}
   
   
   	public function matchCondition($args, $env) {
   
   		if( !$this->condition ){
   			return true;
   		}
   
   		// set array to prevent error on array_merge
   		if(!is_array($this->frames)) {
                $this->frames = array();
           }
   
   		$frame = $this->compileParams($env, array_merge($this->frames,$env->frames), $args );
   
   		$compile_env = new Less_Environment();
   		$compile_env->frames = array_merge(
   				array($frame)		// the parameter variables
   				, $this->frames		// the parent namespace/mixin frames
   				, $env->frames		// the current environment frames
   			);
   
   		$compile_env->functions = $env->functions;
   
   		return (bool)$this->condition->compile($compile_env);
   	}
   
   	public function matchArgs($args, $env = NULL){
   		$argsLength = count($args);
   
   		if( !$this->variadic ){
   			if( $argsLength < $this->required ){
   				return false;
   			}
   			if( $argsLength > count($this->params) ){
   				return false;
   			}
   		}else{
   			if( $argsLength < ($this->required - 1)){
   				return false;
   			}
   		}
   
   		$len = min($argsLength, $this->arity);
   
   		for( $i = 0; $i < $len; $i++ ){
   			if( !isset($this->params[$i]['name']) && !isset($this->params[$i]['variadic']) ){
   				if( $args[$i]['value']->compile($env)->toCSS() != $this->params[$i]['value']->compile($env)->toCSS() ){
   					return false;
   				}
   			}
   		}
   
   		return true;
   	}
   
   }
    
   
   /**
    * Extend Finder Visitor
    *
    * @package Less
    * @subpackage visitor
    */
   class Less_Visitor_extendFinder extends Less_Visitor{
   
   	public $contexts = array();
   	public $allExtendsStack;
   	public $foundExtends;
   
   	public function __construct(){
   		$this->contexts = array();
   		$this->allExtendsStack = array(array());
   		parent::__construct();
   	}
   
   	/**
   	 * @param Less_Tree_Ruleset $root
   	 */
       public function run($root){
   		$root = $this->visitObj($root);
   		$root->allExtends =& $this->allExtendsStack[0];
   		return $root;
   	}
   
       public function visitRule($ruleNode, &$visitDeeper ){
   		$visitDeeper = false;
   	}
   
       public function visitMixinDefinition( $mixinDefinitionNode, &$visitDeeper ){
   		$visitDeeper = false;
   	}
   
       public function visitRuleset($rulesetNode){
   
   		if( $rulesetNode->root ){
   			return;
   		}
   
   		$allSelectorsExtendList = array();
   
   		// get &:extend(.a); rules which apply to all selectors in this ruleset
   		if( $rulesetNode->rules ){
   			foreach($rulesetNode->rules as $rule){
   				if( $rule instanceof Less_Tree_Extend ){
   					$allSelectorsExtendList[] = $rule;
   					$rulesetNode->extendOnEveryPath = true;
   				}
   			}
   		}
   
   
   		// now find every selector and apply the extends that apply to all extends
   		// and the ones which apply to an individual extend
   		foreach($rulesetNode->paths as $selectorPath){
   			$selector = end($selectorPath); //$selectorPath[ count($selectorPath)-1];
   
   			$j = 0;
   			foreach($selector->extendList as $extend){
   				$this->allExtendsStackPush($rulesetNode, $selectorPath, $extend, $j);
   			}
   			foreach($allSelectorsExtendList as $extend){
   				$this->allExtendsStackPush($rulesetNode, $selectorPath, $extend, $j);
   			}
   		}
   
   		$this->contexts[] = $rulesetNode->selectors;
   	}
   
       public function allExtendsStackPush($rulesetNode, $selectorPath, $extend, &$j){
   		$this->foundExtends = true;
   		$extend = clone $extend;
   		$extend->findSelfSelectors( $selectorPath );
   		$extend->ruleset = $rulesetNode;
   		if( $j === 0 ){
   			$extend->firstExtendOnThisSelectorPath = true;
   		}
   
   		$end_key = count($this->allExtendsStack)-1;
   		$this->allExtendsStack[$end_key][] = $extend;
   		$j++;
   	}
   
   
       public function visitRulesetOut( $rulesetNode ){
   		if( !is_object($rulesetNode) || !$rulesetNode->root ){
   			array_pop($this->contexts);
   		}
   	}
   
       public function visitMedia( $mediaNode ){
   		$mediaNode->allExtends = array();
   		$this->allExtendsStack[] =& $mediaNode->allExtends;
   	}
   
       public function visitMediaOut(){
   		array_pop($this->allExtendsStack);
   	}
   
       public function visitDirective( $directiveNode ){
   		$directiveNode->allExtends = array();
   		$this->allExtendsStack[] =& $directiveNode->allExtends;
   	}
   
       public function visitDirectiveOut(){
   		array_pop($this->allExtendsStack);
   	}
   }
   
   
    
   
   /*
   class Less_Visitor_import extends Less_VisitorReplacing{
   
   	public $_visitor;
   	public $_importer;
   	public $importCount;
   
   	function __construct( $evalEnv ){
   		$this->env = $evalEnv;
   		$this->importCount = 0;
   		parent::__construct();
   	}
   
   
   	function run( $root ){
   		$root = $this->visitObj($root);
   		$this->isFinished = true;
   
   		//if( $this->importCount === 0) {
   		//	$this->_finish();
   		//}
   	}
   
   	function visitImport($importNode, &$visitDeeper ){
   		$importVisitor = $this;
   		$inlineCSS = $importNode->options['inline'];
   
   		if( !$importNode->css || $inlineCSS ){
   			$evaldImportNode = $importNode->compileForImport($this->env);
   
   			if( $evaldImportNode && (!$evaldImportNode->css || $inlineCSS) ){
   				$importNode = $evaldImportNode;
   				$this->importCount++;
   				$env = clone $this->env;
   
   				if( (isset($importNode->options['multiple']) && $importNode->options['multiple']) ){
   					$env->importMultiple = true;
   				}
   
   				//get path & uri
   				$path_and_uri = null;
   				if( is_callable(Less_Parser::$options['import_callback']) ){
   					$path_and_uri = call_user_func(Less_Parser::$options['import_callback'],$importNode);
   				}
   
   				if( !$path_and_uri ){
   					$path_and_uri = $importNode->PathAndUri();
   				}
   
   				if( $path_and_uri ){
   					list($full_path, $uri) = $path_and_uri;
   				}else{
   					$full_path = $uri = $importNode->getPath();
   				}
   
   
   				//import once
   				if( $importNode->skip( $full_path, $env) ){
   					return array();
   				}
   
   				if( $importNode->options['inline'] ){
   					//todo needs to reference css file not import
   					//$contents = new Less_Tree_Anonymous($importNode->root, 0, array('filename'=>$importNode->importedFilename), true );
   
   					Less_Parser::AddParsedFile($full_path);
   					$contents = new Less_Tree_Anonymous( file_get_contents($full_path), 0, array(), true );
   
   					if( $importNode->features ){
   						return new Less_Tree_Media( array($contents), $importNode->features->value );
   					}
   
   					return array( $contents );
   				}
   
   
   				// css ?
   				if( $importNode->css ){
   					$features = ( $importNode->features ? $importNode->features->compile($env) : null );
   					return new Less_Tree_Import( $importNode->compilePath( $env), $features, $importNode->options, $this->index);
   				}
   
   				return $importNode->ParseImport( $full_path, $uri, $env );
   			}
   
   		}
   
   		$visitDeeper = false;
   		return $importNode;
   	}
   
   
   	function visitRule( $ruleNode, &$visitDeeper ){
   		$visitDeeper = false;
   		return $ruleNode;
   	}
   
   	function visitDirective($directiveNode, $visitArgs){
   		array_unshift($this->env->frames,$directiveNode);
   		return $directiveNode;
   	}
   
   	function visitDirectiveOut($directiveNode) {
   		array_shift($this->env->frames);
   	}
   
   	function visitMixinDefinition($mixinDefinitionNode, $visitArgs) {
   		array_unshift($this->env->frames,$mixinDefinitionNode);
   		return $mixinDefinitionNode;
   	}
   
   	function visitMixinDefinitionOut($mixinDefinitionNode) {
   		array_shift($this->env->frames);
   	}
   
   	function visitRuleset($rulesetNode, $visitArgs) {
   		array_unshift($this->env->frames,$rulesetNode);
   		return $rulesetNode;
   	}
   
   	function visitRulesetOut($rulesetNode) {
   		array_shift($this->env->frames);
   	}
   
   	function visitMedia($mediaNode, $visitArgs) {
   		array_unshift($this->env->frames, $mediaNode->ruleset);
   		return $mediaNode;
   	}
   
   	function visitMediaOut($mediaNode) {
   		array_shift($this->env->frames);
   	}
   
   }
   */
   
   
    
   
   /**
    * Join Selector Visitor
    *
    * @package Less
    * @subpackage visitor
    */
   class Less_Visitor_joinSelector extends Less_Visitor{
   
   	public $contexts = array( array() );
   
   	/**
   	 * @param Less_Tree_Ruleset $root
   	 */
   	public function run( $root ){
   		return $this->visitObj($root);
   	}
   
       public function visitRule( $ruleNode, &$visitDeeper ){
   		$visitDeeper = false;
   	}
   
       public function visitMixinDefinition( $mixinDefinitionNode, &$visitDeeper ){
   		$visitDeeper = false;
   	}
   
       public function visitRuleset( $rulesetNode ){
   
   		$paths = array();
   
   		if( !$rulesetNode->root ){
   			$selectors = array();
   
   			if( $rulesetNode->selectors && $rulesetNode->selectors ){
   				foreach($rulesetNode->selectors as $selector){
   					if( $selector->getIsOutput() ){
   						$selectors[] = $selector;
   					}
   				}
   			}
   
   			if( !$selectors ){
   				$rulesetNode->selectors = null;
   				$rulesetNode->rules = null;
   			}else{
   				$context = end($this->contexts); //$context = $this->contexts[ count($this->contexts) - 1];
   				$paths = $rulesetNode->joinSelectors( $context, $selectors);
   			}
   
   			$rulesetNode->paths = $paths;
   		}
   
   		$this->contexts[] = $paths; //different from less.js. Placed after joinSelectors() so that $this->contexts will get correct $paths
   	}
   
       public function visitRulesetOut(){
   		array_pop($this->contexts);
   	}
   
       public function visitMedia($mediaNode) {
   		$context = end($this->contexts); //$context = $this->contexts[ count($this->contexts) - 1];
   
   		if( !count($context) || (is_object($context[0]) && $context[0]->multiMedia) ){
   			$mediaNode->rules[0]->root = true;
   		}
   	}
   
   }
   
    
   
   /**
    * Process Extends Visitor
    *
    * @package Less
    * @subpackage visitor
    */
   class Less_Visitor_processExtends extends Less_Visitor{
   
   	public $allExtendsStack;
   
   	/**
   	 * @param Less_Tree_Ruleset $root
   	 */
   	public function run( $root ){
   		$extendFinder = new Less_Visitor_extendFinder();
   		$extendFinder->run( $root );
   		if( !$extendFinder->foundExtends){
   			return $root;
   		}
   
   		$root->allExtends = $this->doExtendChaining( $root->allExtends, $root->allExtends);
   
   		$this->allExtendsStack = array();
   		$this->allExtendsStack[] = &$root->allExtends;
   
   		return $this->visitObj( $root );
   	}
   
   	private function doExtendChaining( $extendsList, $extendsListTarget, $iterationCount = 0){
   		//
   		// chaining is different from normal extension.. if we extend an extend then we are not just copying, altering and pasting
   		// the selector we would do normally, but we are also adding an extend with the same target selector
   		// this means this new extend can then go and alter other extends
   		//
   		// this method deals with all the chaining work - without it, extend is flat and doesn't work on other extend selectors
   		// this is also the most expensive.. and a match on one selector can cause an extension of a selector we had already processed if
   		// we look at each selector at a time, as is done in visitRuleset
   
   		$extendsToAdd = array();
   
   
   		//loop through comparing every extend with every target extend.
   		// a target extend is the one on the ruleset we are looking at copy/edit/pasting in place
   		// e.g. .a:extend(.b) {} and .b:extend(.c) {} then the first extend extends the second one
   		// and the second is the target.
   		// the seperation into two lists allows us to process a subset of chains with a bigger set, as is the
   		// case when processing media queries
   		for( $extendIndex = 0, $extendsList_len = count($extendsList); $extendIndex < $extendsList_len; $extendIndex++ ){
   			for( $targetExtendIndex = 0; $targetExtendIndex < count($extendsListTarget); $targetExtendIndex++ ){
   
   				$extend = $extendsList[$extendIndex];
   				$targetExtend = $extendsListTarget[$targetExtendIndex];
   
   				// look for circular references
   				if( in_array($targetExtend->object_id, $extend->parent_ids,true) ){
   					continue;
   				}
   
   				// find a match in the target extends self selector (the bit before :extend)
   				$selectorPath = array( $targetExtend->selfSelectors[0] );
   				$matches = $this->findMatch( $extend, $selectorPath);
   
   
   				if( $matches ){
   
   					// we found a match, so for each self selector..
   					foreach($extend->selfSelectors as $selfSelector ){
   
   
   						// process the extend as usual
   						$newSelector = $this->extendSelector( $matches, $selectorPath, $selfSelector);
   
   						// but now we create a new extend from it
   						$newExtend = new Less_Tree_Extend( $targetExtend->selector, $targetExtend->option, 0);
   						$newExtend->selfSelectors = $newSelector;
   
   						// add the extend onto the list of extends for that selector
   						end($newSelector)->extendList = array($newExtend);
   						//$newSelector[ count($newSelector)-1]->extendList = array($newExtend);
   
   						// record that we need to add it.
   						$extendsToAdd[] = $newExtend;
   						$newExtend->ruleset = $targetExtend->ruleset;
   
   						//remember its parents for circular references
   						$newExtend->parent_ids = array_merge($newExtend->parent_ids,$targetExtend->parent_ids,$extend->parent_ids);
   
   						// only process the selector once.. if we have :extend(.a,.b) then multiple
   						// extends will look at the same selector path, so when extending
   						// we know that any others will be duplicates in terms of what is added to the css
   						if( $targetExtend->firstExtendOnThisSelectorPath ){
   							$newExtend->firstExtendOnThisSelectorPath = true;
   							$targetExtend->ruleset->paths[] = $newSelector;
   						}
   					}
   				}
   			}
   		}
   
   		if( $extendsToAdd ){
   			// try to detect circular references to stop a stack overflow.
   			// may no longer be needed.			$this->extendChainCount++;
   			if( $iterationCount > 100) {
   
   				try{
   					$selectorOne = $extendsToAdd[0]->selfSelectors[0]->toCSS();
   					$selectorTwo = $extendsToAdd[0]->selector->toCSS();
   				}catch(Exception $e){
   					$selectorOne = "{unable to calculate}";
   					$selectorTwo = "{unable to calculate}";
   				}
   
   				throw new Less_Exception_Parser("extend circular reference detected. One of the circular extends is currently:" . $selectorOne . ":extend(" . $selectorTwo . ")");
   			}
   
   			// now process the new extends on the existing rules so that we can handle a extending b extending c ectending d extending e...
   			$extendsToAdd = $this->doExtendChaining( $extendsToAdd, $extendsListTarget, $iterationCount+1);
   		}
   
   		return array_merge($extendsList, $extendsToAdd);
   	}
   
   
   	protected function visitRule( $ruleNode, &$visitDeeper ){
   		$visitDeeper = false;
   	}
   
   	protected function visitMixinDefinition( $mixinDefinitionNode, &$visitDeeper ){
   		$visitDeeper = false;
   	}
   
   	protected function visitSelector( $selectorNode, &$visitDeeper ){
   		$visitDeeper = false;
   	}
   
   	protected function visitRuleset($rulesetNode){
   
   
   		if( $rulesetNode->root ){
   			return;
   		}
   
   		$allExtends	= end($this->allExtendsStack);
   		$paths_len = count($rulesetNode->paths);
   
   		// look at each selector path in the ruleset, find any extend matches and then copy, find and replace
   		foreach($allExtends as $allExtend){
   			for($pathIndex = 0; $pathIndex < $paths_len; $pathIndex++ ){
   
   				// extending extends happens initially, before the main pass
   				if( isset($rulesetNode->extendOnEveryPath) && $rulesetNode->extendOnEveryPath ){
   					continue;
   				}
   
   				$selectorPath = $rulesetNode->paths[$pathIndex];
   
   				if( end($selectorPath)->extendList ){
   					continue;
   				}
   
   				$this->ExtendMatch( $rulesetNode, $allExtend, $selectorPath);
   
   			}
   		}
   	}
   
   
   	private function ExtendMatch( $rulesetNode, $extend, $selectorPath ){
   		$matches = $this->findMatch($extend, $selectorPath);
   
   		if( $matches ){
   			foreach($extend->selfSelectors as $selfSelector ){
   				$rulesetNode->paths[] = $this->extendSelector($matches, $selectorPath, $selfSelector);
   			}
   		}
   	}
   
   
   
   	private function findMatch($extend, $haystackSelectorPath ){
   
   
   		if( !$this->HasMatches($extend, $haystackSelectorPath) ){
   			return false;
   		}
   
   
   		//
   		// look through the haystack selector path to try and find the needle - extend.selector
   		// returns an array of selector matches that can then be replaced
   		//
   		$needleElements = $extend->selector->elements;
   		$potentialMatches = array();
   		$potentialMatches_len = 0;
   		$potentialMatch = null;
   		$matches = array();
   
   
   
   		// loop through the haystack elements
   		$haystack_path_len = count($haystackSelectorPath);
   		for($haystackSelectorIndex = 0; $haystackSelectorIndex < $haystack_path_len; $haystackSelectorIndex++ ){
   			$hackstackSelector = $haystackSelectorPath[$haystackSelectorIndex];
   
   			$haystack_elements_len = count($hackstackSelector->elements);
   			for($hackstackElementIndex = 0; $hackstackElementIndex < $haystack_elements_len; $hackstackElementIndex++ ){
   
   				$haystackElement = $hackstackSelector->elements[$hackstackElementIndex];
   
   				// if we allow elements before our match we can add a potential match every time. otherwise only at the first element.
   				if( $extend->allowBefore || ($haystackSelectorIndex === 0 && $hackstackElementIndex === 0) ){
   					$potentialMatches[] = array('pathIndex'=> $haystackSelectorIndex, 'index'=> $hackstackElementIndex, 'matched'=> 0, 'initialCombinator'=> $haystackElement->combinator);
   					$potentialMatches_len++;
   				}
   
   				for($i = 0; $i < $potentialMatches_len; $i++ ){
   
   					$potentialMatch = &$potentialMatches[$i];
   					$potentialMatch = $this->PotentialMatch( $potentialMatch, $needleElements, $haystackElement, $hackstackElementIndex );
   
   
   					// if we are still valid and have finished, test whether we have elements after and whether these are allowed
   					if( $potentialMatch && $potentialMatch['matched'] === $extend->selector->elements_len ){
   						$potentialMatch['finished'] = true;
   
   						if( !$extend->allowAfter && ($hackstackElementIndex+1 < $haystack_elements_len || $haystackSelectorIndex+1 < $haystack_path_len) ){
   							$potentialMatch = null;
   						}
   					}
   
   					// if null we remove, if not, we are still valid, so either push as a valid match or continue
   					if( $potentialMatch ){
   						if( $potentialMatch['finished'] ){
   							$potentialMatch['length'] = $extend->selector->elements_len;
   							$potentialMatch['endPathIndex'] = $haystackSelectorIndex;
   							$potentialMatch['endPathElementIndex'] = $hackstackElementIndex + 1; // index after end of match
   							$potentialMatches = array(); // we don't allow matches to overlap, so start matching again
   							$potentialMatches_len = 0;
   							$matches[] = $potentialMatch;
   						}
   						continue;
   					}
   
   					array_splice($potentialMatches, $i, 1);
   					$potentialMatches_len--;
   					$i--;
   				}
   			}
   		}
   
   		return $matches;
   	}
   
   
   	// Before going through all the nested loops, lets check to see if a match is possible
   	// Reduces Bootstrap 3.1 compile time from ~6.5s to ~5.6s
   	private function HasMatches($extend, $haystackSelectorPath){
   
   		if( !$extend->selector->cacheable ){
   			return true;
   		}
   
   		$first_el = $extend->selector->_oelements[0];
   
   		foreach($haystackSelectorPath as $hackstackSelector){
   			if( !$hackstackSelector->cacheable ){
   				return true;
   			}
   
   			if( in_array($first_el, $hackstackSelector->_oelements) ){
   				return true;
   			}
   		}
   
   		return false;
   	}
   
   
   	/**
   	 * @param integer $hackstackElementIndex
   	 */
   	private function PotentialMatch( $potentialMatch, $needleElements, $haystackElement, $hackstackElementIndex ){
   
   
   		if( $potentialMatch['matched'] > 0 ){
   
   			// selectors add " " onto the first element. When we use & it joins the selectors together, but if we don't
   			// then each selector in haystackSelectorPath has a space before it added in the toCSS phase. so we need to work out
   			// what the resulting combinator will be
   			$targetCombinator = $haystackElement->combinator;
   			if( $targetCombinator === '' && $hackstackElementIndex === 0 ){
   				$targetCombinator = ' ';
   			}
   
   			if( $needleElements[ $potentialMatch['matched'] ]->combinator !== $targetCombinator ){
   				return null;
   			}
   		}
   
   		// if we don't match, null our match to indicate failure
   		if( !$this->isElementValuesEqual( $needleElements[$potentialMatch['matched'] ]->value, $haystackElement->value) ){
   			return null;
   		}
   
   		$potentialMatch['finished'] = false;
   		$potentialMatch['matched']++;
   
   		return $potentialMatch;
   	}
   
   
   	private function isElementValuesEqual( $elementValue1, $elementValue2 ){
   
   		if( $elementValue1 === $elementValue2 ){
   			return true;
   		}
   
   		if( is_string($elementValue1) || is_string($elementValue2) ) {
   			return false;
   		}
   
   		if( $elementValue1 instanceof Less_Tree_Attribute ){
   			return $this->isAttributeValuesEqual( $elementValue1, $elementValue2 );
   		}
   
   		$elementValue1 = $elementValue1->value;
   		if( $elementValue1 instanceof Less_Tree_Selector ){
   			return $this->isSelectorValuesEqual( $elementValue1, $elementValue2 );
   		}
   
   		return false;
   	}
   
   
   	/**
   	 * @param Less_Tree_Selector $elementValue1
   	 */
   	private function isSelectorValuesEqual( $elementValue1, $elementValue2 ){
   
   		$elementValue2 = $elementValue2->value;
   		if( !($elementValue2 instanceof Less_Tree_Selector) || $elementValue1->elements_len !== $elementValue2->elements_len ){
   			return false;
   		}
   
   		for( $i = 0; $i < $elementValue1->elements_len; $i++ ){
   
   			if( $elementValue1->elements[$i]->combinator !== $elementValue2->elements[$i]->combinator ){
   				if( $i !== 0 || ($elementValue1->elements[$i]->combinator || ' ') !== ($elementValue2->elements[$i]->combinator || ' ') ){
   					return false;
   				}
   			}
   
   			if( !$this->isElementValuesEqual($elementValue1->elements[$i]->value, $elementValue2->elements[$i]->value) ){
   				return false;
   			}
   		}
   
   		return true;
   	}
   
   
   	/**
   	 * @param Less_Tree_Attribute $elementValue1
   	 */
   	private function isAttributeValuesEqual( $elementValue1, $elementValue2 ){
   
   		if( $elementValue1->op !== $elementValue2->op || $elementValue1->key !== $elementValue2->key ){
   			return false;
   		}
   
   		if( !$elementValue1->value || !$elementValue2->value ){
   			if( $elementValue1->value || $elementValue2->value ) {
   				return false;
   			}
   			return true;
   		}
   
   		$elementValue1 = ($elementValue1->value->value ? $elementValue1->value->value : $elementValue1->value );
   		$elementValue2 = ($elementValue2->value->value ? $elementValue2->value->value : $elementValue2->value );
   
   		return $elementValue1 === $elementValue2;
   	}
   
   
   	private function extendSelector($matches, $selectorPath, $replacementSelector){
   
   		//for a set of matches, replace each match with the replacement selector
   
   		$currentSelectorPathIndex = 0;
   		$currentSelectorPathElementIndex = 0;
   		$path = array();
   		$selectorPath_len = count($selectorPath);
   
   		for($matchIndex = 0, $matches_len = count($matches); $matchIndex < $matches_len; $matchIndex++ ){
   
   
   			$match = $matches[$matchIndex];
   			$selector = $selectorPath[ $match['pathIndex'] ];
   
   			$firstElement = new Less_Tree_Element(
   				$match['initialCombinator'],
   				$replacementSelector->elements[0]->value,
   				$replacementSelector->elements[0]->index,
   				$replacementSelector->elements[0]->currentFileInfo
   			);
   
   			if( $match['pathIndex'] > $currentSelectorPathIndex && $currentSelectorPathElementIndex > 0 ){
   				$last_path = end($path);
   				$last_path->elements = array_merge( $last_path->elements, array_slice( $selectorPath[$currentSelectorPathIndex]->elements, $currentSelectorPathElementIndex));
   				$currentSelectorPathElementIndex = 0;
   				$currentSelectorPathIndex++;
   			}
   
   			$newElements = array_merge(
   				array_slice($selector->elements, $currentSelectorPathElementIndex, ($match['index'] - $currentSelectorPathElementIndex) ) // last parameter of array_slice is different than the last parameter of javascript's slice
   				, array($firstElement)
   				, array_slice($replacementSelector->elements,1)
   				);
   
   			if( $currentSelectorPathIndex === $match['pathIndex'] && $matchIndex > 0 ){
   				$last_key = count($path)-1;
   				$path[$last_key]->elements = array_merge($path[$last_key]->elements,$newElements);
   			}else{
   				$path = array_merge( $path, array_slice( $selectorPath, $currentSelectorPathIndex, $match['pathIndex'] ));
   				$path[] = new Less_Tree_Selector( $newElements );
   			}
   
   			$currentSelectorPathIndex = $match['endPathIndex'];
   			$currentSelectorPathElementIndex = $match['endPathElementIndex'];
   			if( $currentSelectorPathElementIndex >= count($selectorPath[$currentSelectorPathIndex]->elements) ){
   				$currentSelectorPathElementIndex = 0;
   				$currentSelectorPathIndex++;
   			}
   		}
   
   		if( $currentSelectorPathIndex < $selectorPath_len && $currentSelectorPathElementIndex > 0 ){
   			$last_path = end($path);
   			$last_path->elements = array_merge( $last_path->elements, array_slice($selectorPath[$currentSelectorPathIndex]->elements, $currentSelectorPathElementIndex));
   			$currentSelectorPathIndex++;
   		}
   
   		$slice_len = $selectorPath_len - $currentSelectorPathIndex;
   		$path = array_merge($path, array_slice($selectorPath, $currentSelectorPathIndex, $slice_len));
   
   		return $path;
   	}
   
   
   	protected function visitMedia( $mediaNode ){
   		$newAllExtends = array_merge( $mediaNode->allExtends, end($this->allExtendsStack) );
   		$this->allExtendsStack[] = $this->doExtendChaining($newAllExtends, $mediaNode->allExtends);
   	}
   
   	protected function visitMediaOut(){
   		array_pop( $this->allExtendsStack );
   	}
   
   	protected function visitDirective( $directiveNode ){
   		$newAllExtends = array_merge( $directiveNode->allExtends, end($this->allExtendsStack) );
   		$this->allExtendsStack[] = $this->doExtendChaining($newAllExtends, $directiveNode->allExtends);
   	}
   
   	protected function visitDirectiveOut(){
   		array_pop($this->allExtendsStack);
   	}
   
   } 
   
   /**
    * toCSS Visitor
    *
    * @package Less
    * @subpackage visitor
    */
   class Less_Visitor_toCSS extends Less_VisitorReplacing{
   
   	private $charset;
   
   	public function __construct(){
   		parent::__construct();
   	}
   
   	/**
   	 * @param Less_Tree_Ruleset $root
   	 */
   	public function run( $root ){
   		return $this->visitObj($root);
   	}
   
   	public function visitRule( $ruleNode ){
   		if( $ruleNode->variable ){
   			return array();
   		}
   		return $ruleNode;
   	}
   
   	public function visitMixinDefinition($mixinNode){
   		// mixin definitions do not get eval'd - this means they keep state
   		// so we have to clear that state here so it isn't used if toCSS is called twice
   		$mixinNode->frames = array();
   		return array();
   	}
   
   	public function visitExtend(){
   		return array();
   	}
   
   	public function visitComment( $commentNode ){
   		if( $commentNode->isSilent() ){
   			return array();
   		}
   		return $commentNode;
   	}
   
   	public function visitMedia( $mediaNode, &$visitDeeper ){
   		$mediaNode->accept($this);
   		$visitDeeper = false;
   
   		if( !$mediaNode->rules ){
   			return array();
   		}
   		return $mediaNode;
   	}
   
   	public function visitDirective( $directiveNode ){
   		if( isset($directiveNode->currentFileInfo['reference']) && (!property_exists($directiveNode,'isReferenced') || !$directiveNode->isReferenced) ){
   			return array();
   		}
   		if( $directiveNode->name === '@charset' ){
   			// Only output the debug info together with subsequent @charset definitions
   			// a comment (or @media statement) before the actual @charset directive would
   			// be considered illegal css as it has to be on the first line
   			if( isset($this->charset) && $this->charset ){
   
   				//if( $directiveNode->debugInfo ){
   				//	$comment = new Less_Tree_Comment('/* ' . str_replace("\n",'',$directiveNode->toCSS())." */\n");
   				//	$comment->debugInfo = $directiveNode->debugInfo;
   				//	return $this->visit($comment);
   				//}
   
   
   				return array();
   			}
   			$this->charset = true;
   		}
   		return $directiveNode;
   	}
   
   	public function checkPropertiesInRoot( $rulesetNode ){
   
   		if( !$rulesetNode->firstRoot ){
   			return;
   		}
   
   		foreach($rulesetNode->rules as $ruleNode){
   			if( $ruleNode instanceof Less_Tree_Rule && !$ruleNode->variable ){
   				$msg = "properties must be inside selector blocks, they cannot be in the root. Index ".$ruleNode->index.($ruleNode->currentFileInfo ? (' Filename: '.$ruleNode->currentFileInfo['filename']) : null);
   				throw new Less_Exception_Compiler($msg);
   			}
   		}
   	}
   
   
   	public function visitRuleset( $rulesetNode, &$visitDeeper ){
   
   		$visitDeeper = false;
   
   		$this->checkPropertiesInRoot( $rulesetNode );
   
   		if( $rulesetNode->root ){
   			return $this->visitRulesetRoot( $rulesetNode );
   		}
   
   		$rulesets = array();
   		$rulesetNode->paths = $this->visitRulesetPaths($rulesetNode);
   
   
   		// Compile rules and rulesets
   		$nodeRuleCnt = count($rulesetNode->rules);
   		for( $i = 0; $i < $nodeRuleCnt; ){
   			$rule = $rulesetNode->rules[$i];
   
   			if( property_exists($rule,'rules') ){
   				// visit because we are moving them out from being a child
   				$rulesets[] = $this->visitObj($rule);
   				array_splice($rulesetNode->rules,$i,1);
   				$nodeRuleCnt--;
   				continue;
   			}
   			$i++;
   		}
   
   
   		// accept the visitor to remove rules and refactor itself
   		// then we can decide now whether we want it or not
   		if( $nodeRuleCnt > 0 ){
   			$rulesetNode->accept($this);
   
   			if( $rulesetNode->rules ){
   
   				if( count($rulesetNode->rules) >  1 ){
   					$this->_mergeRules( $rulesetNode->rules );
   					$this->_removeDuplicateRules( $rulesetNode->rules );
   				}
   
   				// now decide whether we keep the ruleset
   				if( $rulesetNode->paths ){
   					//array_unshift($rulesets, $rulesetNode);
   					array_splice($rulesets,0,0,array($rulesetNode));
   				}
   			}
   
   		}
   
   
   		if( count($rulesets) === 1 ){
   			return $rulesets[0];
   		}
   		return $rulesets;
   	}
   
   
   	/**
   	 * Helper function for visitiRuleset
   	 *
   	 * return array|Less_Tree_Ruleset
   	 */
   	private function visitRulesetRoot( $rulesetNode ){
   		$rulesetNode->accept( $this );
   		if( $rulesetNode->firstRoot || $rulesetNode->rules ){
   			return $rulesetNode;
   		}
   		return array();
   	}
   
   
   	/**
   	 * Helper function for visitRuleset()
   	 *
   	 * @return array
   	 */
   	private function visitRulesetPaths($rulesetNode){
   
   		$paths = array();
   		foreach($rulesetNode->paths as $p){
   			if( $p[0]->elements[0]->combinator === ' ' ){
   				$p[0]->elements[0]->combinator = '';
   			}
   
   			foreach($p as $pi){
   				if( $pi->getIsReferenced() && $pi->getIsOutput() ){
   					$paths[] = $p;
   					break;
   				}
   			}
   		}
   
   		return $paths;
   	}
   
   	protected function _removeDuplicateRules( &$rules ){
   		// remove duplicates
   		$ruleCache = array();
   		for( $i = count($rules)-1; $i >= 0 ; $i-- ){
   			$rule = $rules[$i];
   			if( $rule instanceof Less_Tree_Rule || $rule instanceof Less_Tree_NameValue ){
   
   				if( !isset($ruleCache[$rule->name]) ){
   					$ruleCache[$rule->name] = $rule;
   				}else{
   					$ruleList =& $ruleCache[$rule->name];
   
   					if( $ruleList instanceof Less_Tree_Rule || $ruleList instanceof Less_Tree_NameValue ){
   						$ruleList = $ruleCache[$rule->name] = array( $ruleCache[$rule->name]->toCSS() );
   					}
   
   					$ruleCSS = $rule->toCSS();
   					if( array_search($ruleCSS,$ruleList) !== false ){
   						array_splice($rules,$i,1);
   					}else{
   						$ruleList[] = $ruleCSS;
   					}
   				}
   			}
   		}
   	}
   
   	protected function _mergeRules( &$rules ){
   		$groups = array();
   
   		//obj($rules);
   
   		$rules_len = count($rules);
   		for( $i = 0; $i < $rules_len; $i++ ){
   			$rule = $rules[$i];
   
   			if( ($rule instanceof Less_Tree_Rule) && $rule->merge ){
   
   				$key = $rule->name;
   				if( $rule->important ){
   					$key .= ',!';
   				}
   
   				if( !isset($groups[$key]) ){
   					$groups[$key] = array();
   				}else{
   					array_splice($rules, $i--, 1);
   					$rules_len--;
   				}
   
   				$groups[$key][] = $rule;
   			}
   		}
   
   
   		foreach($groups as $parts){
   
   			if( count($parts) > 1 ){
   				$rule = $parts[0];
   				$spacedGroups = array();
   				$lastSpacedGroup = array();
   				$parts_mapped = array();
   				foreach($parts as $p){
   					if( $p->merge === '+' ){
   						if( $lastSpacedGroup ){
   							$spacedGroups[] = self::toExpression($lastSpacedGroup);
   						}
   						$lastSpacedGroup = array();
   					}
   					$lastSpacedGroup[] = $p;
   				}
   
   				$spacedGroups[] = self::toExpression($lastSpacedGroup);
   				$rule->value = self::toValue($spacedGroups);
   			}
   		}
   
   	}
   
   	public static function toExpression($values){
   		$mapped = array();
   		foreach($values as $p){
   			$mapped[] = $p->value;
   		}
   		return new Less_Tree_Expression( $mapped );
   	}
   
   	public static function toValue($values){
   		//return new Less_Tree_Value($values); ??
   
   		$mapped = array();
   		foreach($values as $p){
   			$mapped[] = $p;
   		}
   		return new Less_Tree_Value($mapped);
   	}
   }
   
    
   
   /**
    * Parser Exception
    *
    * @package Less
    * @subpackage exception
    */
   class Less_Exception_Parser extends Exception{
   
   	/**
   	 * The current file
   	 *
   	 * @var Less_ImportedFile
   	 */
   	public $currentFile;
   
   	/**
   	 * The current parser index
   	 *
   	 * @var integer
   	 */
   	public $index;
   
   	protected $input;
   
   	protected $details = array();
   
   
   	/**
   	 * Constructor
   	 *
   	 * @param string $message
   	 * @param Exception $previous Previous exception
   	 * @param integer $index The current parser index
   	 * @param Less_FileInfo|string $currentFile The file
   	 * @param integer $code The exception code
   	 */
   	public function __construct($message = null, Exception $previous = null, $index = null, $currentFile = null, $code = 0){
   
   		if (PHP_VERSION_ID < 50300) {
   			$this->previous = $previous;
   			parent::__construct($message, $code);
   		} else {
   			parent::__construct($message, $code, $previous);
   		}
   
   		$this->currentFile = $currentFile;
   		$this->index = $index;
   
   		$this->genMessage();
   	}
   
   
   	protected function getInput(){
   
   		if( !$this->input && $this->currentFile && $this->currentFile['filename'] && file_exists($this->currentFile['filename']) ){
   			$this->input = file_get_contents( $this->currentFile['filename'] );
   		}
   	}
   
   
   
   	/**
   	 * Converts the exception to string
   	 *
   	 * @return string
   	 */
   	public function genMessage(){
   
   		if( $this->currentFile && $this->currentFile['filename'] ){
   			$this->message .= ' in '.basename($this->currentFile['filename']);
   		}
   
   		if( $this->index !== null ){
   			$this->getInput();
   			if( $this->input ){
   				$line = self::getLineNumber();
   				$this->message .= ' on line '.$line.', column '.self::getColumn();
   
   				$lines = explode("\n",$this->input);
   
   				$count = count($lines);
   				$start_line = max(0, $line-3);
   				$last_line = min($count, $start_line+6);
   				$num_len = strlen($last_line);
   				for( $i = $start_line; $i < $last_line; $i++ ){
   					$this->message .= "\n".str_pad($i+1,$num_len,'0',STR_PAD_LEFT).'| '.$lines[$i];
   				}
   			}
   		}
   
   	}
   
   	/**
   	 * Returns the line number the error was encountered
   	 *
   	 * @return integer
   	 */
   	public function getLineNumber(){
   		if( $this->index ){
   			// https://bugs.php.net/bug.php?id=49790
   			if (ini_get("mbstring.func_overload")) {
   				return substr_count(substr($this->input, 0, $this->index), "\n") + 1;
   			} else {
   				return substr_count($this->input, "\n", 0, $this->index) + 1;
   			}
   		}
   		return 1;
   	}
   
   
   	/**
   	 * Returns the column the error was encountered
   	 *
   	 * @return integer
   	 */
   	public function getColumn(){
   
   		$part = substr($this->input, 0, $this->index);
   		$pos = strrpos($part,"\n");
   		return $this->index - $pos;
   	}
   
   }
    
   
   /**
    * Chunk Exception
    *
    * @package Less
    * @subpackage exception
    */
   class Less_Exception_Chunk extends Less_Exception_Parser{
   
   
   	protected $parserCurrentIndex = 0;
   
   	protected $emitFrom = 0;
   
   	protected $input_len;
   
   
   	/**
   	 * Constructor
   	 *
   	 * @param string $input
   	 * @param Exception $previous Previous exception
   	 * @param integer $index The current parser index
   	 * @param Less_FileInfo|string $currentFile The file
   	 * @param integer $code The exception code
   	 */
   	public function __construct($input, Exception $previous = null, $index = null, $currentFile = null, $code = 0){
   
   		$this->message = 'ParseError: Unexpected input'; //default message
   
   		$this->index = $index;
   
   		$this->currentFile = $currentFile;
   
   		$this->input = $input;
   		$this->input_len = strlen($input);
   
   		$this->Chunks();
   		$this->genMessage();
   	}
   
   
   	/**
   	 * See less.js chunks()
   	 * We don't actually need the chunks
   	 *
   	 */
   	protected function Chunks(){
   		$level = 0;
   		$parenLevel = 0;
   		$lastMultiCommentEndBrace = null;
   		$lastOpening = null;
   		$lastMultiComment = null;
   		$lastParen = null;
   
   		for( $this->parserCurrentIndex = 0; $this->parserCurrentIndex < $this->input_len; $this->parserCurrentIndex++ ){
   			$cc = $this->CharCode($this->parserCurrentIndex);
   			if ((($cc >= 97) && ($cc <= 122)) || ($cc < 34)) {
   				// a-z or whitespace
   				continue;
   			}
   
   			switch ($cc) {
   
   				// (
   				case 40:
   					$parenLevel++;
   					$lastParen = $this->parserCurrentIndex;
   					break;
   
   				// )
   				case 41:
   					$parenLevel--;
   					if( $parenLevel < 0 ){
   						return $this->fail("missing opening `(`");
   					}
   					break;
   
   				// ;
   				case 59:
   					//if (!$parenLevel) { $this->emitChunk();	}
   					break;
   
   				// {
   				case 123:
   					$level++;
   					$lastOpening = $this->parserCurrentIndex;
   					break;
   
   				// }
   				case 125:
   					$level--;
   					if( $level < 0 ){
   						return $this->fail("missing opening `{`");
   
   					}
   					//if (!$level && !$parenLevel) { $this->emitChunk(); }
   					break;
   				// \
   				case 92:
   					if ($this->parserCurrentIndex < $this->input_len - 1) { $this->parserCurrentIndex++; break; }
   					return $this->fail("unescaped `\\`");
   
   				// ", ' and `
   				case 34:
   				case 39:
   				case 96:
   					$matched = 0;
   					$currentChunkStartIndex = $this->parserCurrentIndex;
   					for ($this->parserCurrentIndex = $this->parserCurrentIndex + 1; $this->parserCurrentIndex < $this->input_len; $this->parserCurrentIndex++) {
   						$cc2 = $this->CharCode($this->parserCurrentIndex);
   						if ($cc2 > 96) { continue; }
   						if ($cc2 == $cc) { $matched = 1; break; }
   						if ($cc2 == 92) {        // \
   							if ($this->parserCurrentIndex == $this->input_len - 1) {
   								return $this->fail("unescaped `\\`");
   							}
   							$this->parserCurrentIndex++;
   						}
   					}
   					if ($matched) { break; }
   					return $this->fail("unmatched `" . chr($cc) . "`", $currentChunkStartIndex);
   
   				// /, check for comment
   				case 47:
   					if ($parenLevel || ($this->parserCurrentIndex == $this->input_len - 1)) { break; }
   					$cc2 = $this->CharCode($this->parserCurrentIndex+1);
   					if ($cc2 == 47) {
   						// //, find lnfeed
   						for ($this->parserCurrentIndex = $this->parserCurrentIndex + 2; $this->parserCurrentIndex < $this->input_len; $this->parserCurrentIndex++) {
   							$cc2 = $this->CharCode($this->parserCurrentIndex);
   							if (($cc2 <= 13) && (($cc2 == 10) || ($cc2 == 13))) { break; }
   						}
   					} else if ($cc2 == 42) {
   						// /*, find */
   						$lastMultiComment = $currentChunkStartIndex = $this->parserCurrentIndex;
   						for ($this->parserCurrentIndex = $this->parserCurrentIndex + 2; $this->parserCurrentIndex < $this->input_len - 1; $this->parserCurrentIndex++) {
   							$cc2 = $this->CharCode($this->parserCurrentIndex);
   							if ($cc2 == 125) { $lastMultiCommentEndBrace = $this->parserCurrentIndex; }
   							if ($cc2 != 42) { continue; }
   							if ($this->CharCode($this->parserCurrentIndex+1) == 47) { break; }
   						}
   						if ($this->parserCurrentIndex == $this->input_len - 1) {
   							return $this->fail("missing closing `*/`", $currentChunkStartIndex);
   						}
   					}
   					break;
   
   				// *, check for unmatched */
   				case 42:
   					if (($this->parserCurrentIndex < $this->input_len - 1) && ($this->CharCode($this->parserCurrentIndex+1) == 47)) {
   						return $this->fail("unmatched `/*`");
   					}
   					break;
   			}
   		}
   
   		if( $level !== 0 ){
   			if( ($lastMultiComment > $lastOpening) && ($lastMultiCommentEndBrace > $lastMultiComment) ){
   				return $this->fail("missing closing `}` or `*/`", $lastOpening);
   			} else {
   				return $this->fail("missing closing `}`", $lastOpening);
   			}
   		} else if ( $parenLevel !== 0 ){
   			return $this->fail("missing closing `)`", $lastParen);
   		}
   
   
   		//chunk didn't fail
   
   
   		//$this->emitChunk(true);
   	}
   
   	public function CharCode($pos){
   		return ord($this->input[$pos]);
   	}
   
   
   	public function fail( $msg, $index = null ){
   
   		if( !$index ){
   			$this->index = $this->parserCurrentIndex;
   		}else{
   			$this->index = $index;
   		}
   		$this->message = 'ParseError: '.$msg;
   	}
   
   
   	/*
   	function emitChunk( $force = false ){
   		$len = $this->parserCurrentIndex - $this->emitFrom;
   		if ((($len < 512) && !$force) || !$len) {
   			return;
   		}
   		$chunks[] = substr($this->input, $this->emitFrom, $this->parserCurrentIndex + 1 - $this->emitFrom );
   		$this->emitFrom = $this->parserCurrentIndex + 1;
   	}
   	*/
   
   }
    
   
   /**
    * Compiler Exception
    *
    * @package Less
    * @subpackage exception
    */
   class Less_Exception_Compiler extends Less_Exception_Parser{
   
   } 
   
   /**
    * Parser output with source map
    *
    * @package Less
    * @subpackage Output
    */
   class Less_Output_Mapped extends Less_Output {
   
   	/**
   	 * The source map generator
   	 *
   	 * @var Less_SourceMap_Generator
   	 */
   	protected $generator;
   
   	/**
   	 * Current line
   	 *
   	 * @var integer
   	 */
   	protected $lineNumber = 0;
   
   	/**
   	 * Current column
   	 *
   	 * @var integer
   	 */
   	protected $column = 0;
   
   	/**
   	 * Array of contents map (file and its content)
   	 *
   	 * @var array
   	 */
   	protected $contentsMap = array();
   
   	/**
   	 * Constructor
   	 *
   	 * @param array $contentsMap Array of filename to contents map
   	 * @param Less_SourceMap_Generator $generator
   	 */
   	public function __construct(array $contentsMap, $generator){
   		$this->contentsMap = $contentsMap;
   		$this->generator = $generator;
   	}
   
   	/**
   	 * Adds a chunk to the stack
   	 * The $index for less.php may be different from less.js since less.php does not chunkify inputs
   	 *
   	 * @param string $chunk
   	 * @param string $fileInfo
   	 * @param integer $index
   	 * @param mixed $mapLines
   	 */
   	public function add($chunk, $fileInfo = null, $index = 0, $mapLines = null){
   
   		//ignore adding empty strings
   		if( $chunk === '' ){
   			return;
   		}
   
   
   		$sourceLines = array();
   		$sourceColumns = ' ';
   
   
   		if( $fileInfo ){
   
   			$url = $fileInfo['currentUri'];
   
   			if( isset($this->contentsMap[$url]) ){
   				$inputSource = substr($this->contentsMap[$url], 0, $index);
   				$sourceLines = explode("\n", $inputSource);
   				$sourceColumns = end($sourceLines);
   			}else{
   				throw new Exception('Filename '.$url.' not in contentsMap');
   			}
   
   		}
   
   		$lines = explode("\n", $chunk);
   		$columns = end($lines);
   
   		if($fileInfo){
   
   			if(!$mapLines){
   				$this->generator->addMapping(
   						$this->lineNumber + 1,					// generated_line
   						$this->column,							// generated_column
   						count($sourceLines),					// original_line
   						strlen($sourceColumns),					// original_column
   						$fileInfo
   				);
   			}else{
   				for($i = 0, $count = count($lines); $i < $count; $i++){
   					$this->generator->addMapping(
   						$this->lineNumber + $i + 1,				// generated_line
   						$i === 0 ? $this->column : 0,			// generated_column
   						count($sourceLines) + $i,				// original_line
   						$i === 0 ? strlen($sourceColumns) : 0, 	// original_column
   						$fileInfo
   					);
   				}
   			}
   		}
   
   		if(count($lines) === 1){
   			$this->column += strlen($columns);
   		}else{
   			$this->lineNumber += count($lines) - 1;
   			$this->column = strlen($columns);
   		}
   
   		// add only chunk
   		parent::add($chunk);
   	}
   
   } 
   
   /**
    * Encode / Decode Base64 VLQ.
    *
    * @package Less
    * @subpackage SourceMap
    */
   class Less_SourceMap_Base64VLQ {
   
   	/**
   	 * Shift
   	 *
   	 * @var integer
   	 */
   	private $shift = 5;
   
   	/**
   	 * Mask
   	 *
   	 * @var integer
   	 */
   	private $mask = 0x1F; // == (1 << shift) == 0b00011111
   
   	/**
   	 * Continuation bit
   	 *
  	 * @var integer
  	 */
  	private $continuationBit = 0x20; // == (mask - 1 ) == 0b00100000
  
  	/**
  	 * Char to integer map
  	 *
  	 * @var array
  	 */
  	private $charToIntMap = array(
  		'A' => 0, 'B' => 1, 'C' => 2, 'D' => 3, 'E' => 4, 'F' => 5, 'G' => 6,
  		'H' => 7,'I' => 8, 'J' => 9, 'K' => 10, 'L' => 11, 'M' => 12, 'N' => 13,
  		'O' => 14, 'P' => 15, 'Q' => 16, 'R' => 17, 'S' => 18, 'T' => 19, 'U' => 20,
  		'V' => 21, 'W' => 22, 'X' => 23, 'Y' => 24, 'Z' => 25, 'a' => 26, 'b' => 27,
  		'c' => 28, 'd' => 29, 'e' => 30, 'f' => 31, 'g' => 32, 'h' => 33, 'i' => 34,
  		'j' => 35, 'k' => 36, 'l' => 37, 'm' => 38, 'n' => 39, 'o' => 40, 'p' => 41,
  		'q' => 42, 'r' => 43, 's' => 44, 't' => 45, 'u' => 46, 'v' => 47, 'w' => 48,
  		'x' => 49, 'y' => 50, 'z' => 51, 0 => 52, 1 => 53, 2 => 54, 3 => 55, 4 => 56,
  		5 => 57,	6 => 58, 7 => 59, 8 => 60, 9 => 61, '+' => 62, '/' => 63,
  	);
  
  	/**
  	 * Integer to char map
  	 *
  	 * @var array
  	 */
  	private $intToCharMap = array(
  		0 => 'A', 1 => 'B', 2 => 'C', 3 => 'D', 4 => 'E', 5 => 'F', 6 => 'G',
  		7 => 'H', 8 => 'I', 9 => 'J', 10 => 'K', 11 => 'L', 12 => 'M', 13 => 'N',
  		14 => 'O', 15 => 'P', 16 => 'Q', 17 => 'R', 18 => 'S', 19 => 'T', 20 => 'U',
  		21 => 'V', 22 => 'W', 23 => 'X', 24 => 'Y', 25 => 'Z', 26 => 'a', 27 => 'b',
  		28 => 'c', 29 => 'd', 30 => 'e', 31 => 'f', 32 => 'g', 33 => 'h', 34 => 'i',
  		35 => 'j', 36 => 'k', 37 => 'l', 38 => 'm', 39 => 'n', 40 => 'o', 41 => 'p',
  		42 => 'q', 43 => 'r', 44 => 's', 45 => 't', 46 => 'u', 47 => 'v', 48 => 'w',
  		49 => 'x', 50 => 'y', 51 => 'z', 52 => '0', 53 => '1', 54 => '2', 55 => '3',
  		56 => '4', 57 => '5', 58 => '6', 59 => '7', 60 => '8', 61 => '9', 62 => '+',
  		63 => '/',
  	);
  
  	/**
  	 * Constructor
  	 */
  	public function __construct(){
  		// I leave it here for future reference
  		// foreach(str_split('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/') as $i => $char)
  		// {
  		//	 $this->charToIntMap[$char] = $i;
  		//	 $this->intToCharMap[$i] = $char;
  		// }
  	}
  
  	/**
  	 * Convert from a two-complement value to a value where the sign bit is
  	 * is placed in the least significant bit.	For example, as decimals:
  	 *	 1 becomes 2 (10 binary), -1 becomes 3 (11 binary)
  	 *	 2 becomes 4 (100 binary), -2 becomes 5 (101 binary)
  	 * We generate the value for 32 bit machines, hence -2147483648 becomes 1, not 4294967297,
  	 * even on a 64 bit machine.
  	 * @param string $aValue
  	 */
  	public function toVLQSigned($aValue){
  		return 0xffffffff & ($aValue < 0 ? ((-$aValue) << 1) + 1 : ($aValue << 1) + 0);
  	}
  
  	/**
  	 * Convert to a two-complement value from a value where the sign bit is
  	 * is placed in the least significant bit. For example, as decimals:
  	 *	 2 (10 binary) becomes 1, 3 (11 binary) becomes -1
  	 *	 4 (100 binary) becomes 2, 5 (101 binary) becomes -2
  	 * We assume that the value was generated with a 32 bit machine in mind.
  	 * Hence
  	 *	 1 becomes -2147483648
  	 * even on a 64 bit machine.
  	 * @param integer $aValue
  	 */
  	public function fromVLQSigned($aValue){
  		return $aValue & 1 ? $this->zeroFill(~$aValue + 2, 1) | (-1 - 0x7fffffff) : $this->zeroFill($aValue, 1);
  	}
  
  	/**
  	 * Return the base 64 VLQ encoded value.
  	 *
  	 * @param string $aValue The value to encode
  	 * @return string The encoded value
  	 */
  	public function encode($aValue){
  		$encoded = '';
  		$vlq = $this->toVLQSigned($aValue);
  		do
  		{
  			$digit = $vlq & $this->mask;
  			$vlq = $this->zeroFill($vlq, $this->shift);
  			if($vlq > 0){
  				$digit |= $this->continuationBit;
  			}
  			$encoded .= $this->base64Encode($digit);
  		} while($vlq > 0);
  
  		return $encoded;
  	}
  
  	/**
  	 * Return the value decoded from base 64 VLQ.
  	 *
  	 * @param string $encoded The encoded value to decode
  	 * @return integer The decoded value
  	 */
  	public function decode($encoded){
  		$vlq = 0;
  		$i = 0;
  		do
  		{
  			$digit = $this->base64Decode($encoded[$i]);
  			$vlq |= ($digit & $this->mask) << ($i * $this->shift);
  			$i++;
  		} while($digit & $this->continuationBit);
  
  		return $this->fromVLQSigned($vlq);
  	}
  
  	/**
  	 * Right shift with zero fill.
  	 *
  	 * @param integer $a number to shift
  	 * @param integer $b number of bits to shift
  	 * @return integer
  	 */
  	public function zeroFill($a, $b){
  		return ($a >= 0) ? ($a >> $b) : ($a >> $b) & (PHP_INT_MAX >> ($b - 1));
  	}
  
  	/**
  	 * Encode single 6-bit digit as base64.
  	 *
  	 * @param integer $number
  	 * @return string
  	 * @throws Exception If the number is invalid
  	 */
  	public function base64Encode($number){
  		if($number < 0 || $number > 63){
  			throw new Exception(sprintf('Invalid number "%s" given. Must be between 0 and 63.', $number));
  		}
  		return $this->intToCharMap[$number];
  	}
  
  	/**
  	 * Decode single 6-bit digit from base64
  	 *
  	 * @param string $char
  	 * @return number
  	 * @throws Exception If the number is invalid
  	 */
  	public function base64Decode($char){
  		if(!array_key_exists($char, $this->charToIntMap)){
  			throw new Exception(sprintf('Invalid base 64 digit "%s" given.', $char));
  		}
  		return $this->charToIntMap[$char];
  	}
  
  }
   
  
  /**
   * Source map generator
   *
   * @package Less
   * @subpackage Output
   */
  class Less_SourceMap_Generator extends Less_Configurable {
  
  	/**
  	 * What version of source map does the generator generate?
  	 */
  	const VERSION = 3;
  
  	/**
  	 * Array of default options
  	 *
  	 * @var array
  	 */
  	protected $defaultOptions = array(
  			// an optional source root, useful for relocating source files
  			// on a server or removing repeated values in the 'sources' entry.
  			// This value is prepended to the individual entries in the 'source' field.
  			'sourceRoot'			=> '',
  
  			// an optional name of the generated code that this source map is associated with.
  			'sourceMapFilename'		=> null,
  
  			// url of the map
  			'sourceMapURL'			=> null,
  
  			// absolute path to a file to write the map to
  			'sourceMapWriteTo'		=> null,
  
  			// output source contents?
  			'outputSourceFiles'		=> false,
  
  			// base path for filename normalization
  			'sourceMapRootpath'		=> '',
  
  			// base path for filename normalization
  			'sourceMapBasepath'   => ''
  	);
  
  	/**
  	 * The base64 VLQ encoder
  	 *
  	 * @var Less_SourceMap_Base64VLQ
  	 */
  	protected $encoder;
  
  	/**
  	 * Array of mappings
  	 *
  	 * @var array
  	 */
  	protected $mappings = array();
  
  	/**
  	 * The root node
  	 *
  	 * @var Less_Tree_Ruleset
  	 */
  	protected $root;
  
  	/**
  	 * Array of contents map
  	 *
  	 * @var array
  	 */
  	protected $contentsMap = array();
  
  	/**
  	 * File to content map
  	 *
  	 * @var array
  	 */
  	protected $sources = array();
  	protected $source_keys = array();
  
  	/**
  	 * Constructor
  	 *
  	 * @param Less_Tree_Ruleset $root The root node
  	 * @param array $options Array of options
  	 */
  	public function __construct(Less_Tree_Ruleset $root, $contentsMap, $options = array()){
  		$this->root = $root;
  		$this->contentsMap = $contentsMap;
  		$this->encoder = new Less_SourceMap_Base64VLQ();
  
  		$this->SetOptions($options);
  		
  		$this->options['sourceMapRootpath'] = $this->fixWindowsPath($this->options['sourceMapRootpath'], true);
  		$this->options['sourceMapBasepath'] = $this->fixWindowsPath($this->options['sourceMapBasepath'], true);
  	}
  
  	/**
  	 * Generates the CSS
  	 *
  	 * @return string
  	 */
  	public function generateCSS(){
  		$output = new Less_Output_Mapped($this->contentsMap, $this);
  
  		// catch the output
  		$this->root->genCSS($output);
  
  
  		$sourceMapUrl				= $this->getOption('sourceMapURL');
  		$sourceMapFilename			= $this->getOption('sourceMapFilename');
  		$sourceMapContent			= $this->generateJson();
  		$sourceMapWriteTo			= $this->getOption('sourceMapWriteTo');
  
  		if( !$sourceMapUrl && $sourceMapFilename ){
  			$sourceMapUrl = $this->normalizeFilename($sourceMapFilename);
  		}
  
  		// write map to a file
  		if( $sourceMapWriteTo ){
  			$this->saveMap($sourceMapWriteTo, $sourceMapContent);
  		}
  
  		// inline the map
  		if( !$sourceMapUrl ){
  			$sourceMapUrl = sprintf('data:application/json,%s', Less_Functions::encodeURIComponent($sourceMapContent));
  		}
  
  		if( $sourceMapUrl ){
  			$output->add( sprintf('/*# sourceMappingURL=%s */', $sourceMapUrl) );
  		}
  
  		return $output->toString();
  	}
  
  	/**
  	 * Saves the source map to a file
  	 *
  	 * @param string $file The absolute path to a file
  	 * @param string $content The content to write
  	 * @throws Exception If the file could not be saved
  	 */
  	protected function saveMap($file, $content){
  		$dir = dirname($file);
  		// directory does not exist
  		if( !is_dir($dir) ){
  			// FIXME: create the dir automatically?
  			throw new Exception(sprintf('The directory "%s" does not exist. Cannot save the source map.', $dir));
  		}
  		// FIXME: proper saving, with dir write check!
  		if(file_put_contents($file, $content) === false){
  			throw new Exception(sprintf('Cannot save the source map to "%s"', $file));
  		}
  		return true;
  	}
  
  	/**
  	 * Normalizes the filename
  	 *
  	 * @param string $filename
  	 * @return string
  	 */
  	protected function normalizeFilename($filename){
  
  		$filename = $this->fixWindowsPath($filename);
  
  		$rootpath = $this->getOption('sourceMapRootpath');
  		$basePath = $this->getOption('sourceMapBasepath');
  
  		// "Trim" the 'sourceMapBasepath' from the output filename.
  		//if (strpos($filename, strval($basePath)) === 0) {
  		//	$filename = substr($filename, strlen($basePath));
  		//}
  
  		// Remove extra leading path separators.
  		if(strpos($filename, '\\') === 0 || strpos($filename, '/') === 0){
  			$filename = substr($filename, 1);
  		}
  
  		return $rootpath . $filename;
  	}
  
  	/**
  	 * Adds a mapping
  	 *
  	 * @param integer $generatedLine The line number in generated file
  	 * @param integer $generatedColumn The column number in generated file
  	 * @param integer $originalLine The line number in original file
  	 * @param integer $originalColumn The column number in original file
  	 * @param string $sourceFile The original source file
  	 */
  	public function addMapping($generatedLine, $generatedColumn, $originalLine, $originalColumn, $fileInfo ){
  
  		$this->mappings[] = array(
  			'generated_line' => $generatedLine,
  			'generated_column' => $generatedColumn,
  			'original_line' => $originalLine,
  			'original_column' => $originalColumn,
  			'source_file' => $fileInfo['currentUri']
  		);
  
  		$this->sources[$fileInfo['currentUri']] = $fileInfo['filename'];
  	}
  
  
  	/**
  	 * Generates the JSON source map
  	 *
  	 * @return string
  	 * @see https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit#
  	 */
  	protected function generateJson(){
  
  		$sourceMap = array();
  		$mappings = $this->generateMappings();
  
  		// File version (always the first entry in the object) and must be a positive integer.
  		$sourceMap['version'] = self::VERSION;
  
  
  		// An optional name of the generated code that this source map is associated with.
  		$file = $this->getOption('sourceMapFilename');
  		if( $file ){
  			$sourceMap['file'] = $file;
  		}
  
  
  		// An optional source root, useful for relocating source files on a server or removing repeated values in the 'sources' entry.	This value is prepended to the individual entries in the 'source' field.
  		$root = $this->getOption('sourceRoot');
  		if( $root ){
  			$sourceMap['sourceRoot'] = $root;
  		}
  
  
  		// A list of original sources used by the 'mappings' entry.
  		$sourceMap['sources'] = array();
  		foreach($this->sources as $source_uri => $source_filename){
  			$sourceMap['sources'][] = $this->normalizeFilename($source_filename);
  		}
  
  
  		// A list of symbol names used by the 'mappings' entry.
  		$sourceMap['names'] = array();
  
  		// A string with the encoded mapping data.
  		$sourceMap['mappings'] = $mappings;
  
  		if( $this->getOption('outputSourceFiles') ){
  			// An optional list of source content, useful when the 'source' can't be hosted.
  			// The contents are listed in the same order as the sources above.
  			// 'null' may be used if some original sources should be retrieved by name.
  			$sourceMap['sourcesContent'] = $this->getSourcesContent();
  		}
  
  		// less.js compat fixes
  		if( count($sourceMap['sources']) && empty($sourceMap['sourceRoot']) ){
  			unset($sourceMap['sourceRoot']);
  		}
  
  		return json_encode($sourceMap);
  	}
  
  	/**
  	 * Returns the sources contents
  	 *
  	 * @return array|null
  	 */
  	protected function getSourcesContent(){
  		if(empty($this->sources)){
  			return;
  		}
  		$content = array();
  		foreach($this->sources as $sourceFile){
  			$content[] = file_get_contents($sourceFile);
  		}
  		return $content;
  	}
  
  	/**
  	 * Generates the mappings string
  	 *
  	 * @return string
  	 */
  	public function generateMappings(){
  
  		if( !count($this->mappings) ){
  			return '';
  		}
  
  		$this->source_keys = array_flip(array_keys($this->sources));
  
  
  		// group mappings by generated line number.
  		$groupedMap = $groupedMapEncoded = array();
  		foreach($this->mappings as $m){
  			$groupedMap[$m['generated_line']][] = $m;
  		}
  		ksort($groupedMap);
  
  		$lastGeneratedLine = $lastOriginalIndex = $lastOriginalLine = $lastOriginalColumn = 0;
  
  		foreach($groupedMap as $lineNumber => $line_map){
  			while(++$lastGeneratedLine < $lineNumber){
  				$groupedMapEncoded[] = ';';
  			}
  
  			$lineMapEncoded = array();
  			$lastGeneratedColumn = 0;
  
  			foreach($line_map as $m){
  				$mapEncoded = $this->encoder->encode($m['generated_column'] - $lastGeneratedColumn);
  				$lastGeneratedColumn = $m['generated_column'];
  
  				// find the index
  				if( $m['source_file'] ){
  					$index = $this->findFileIndex($m['source_file']);
  					if( $index !== false ){
  						$mapEncoded .= $this->encoder->encode($index - $lastOriginalIndex);
  						$lastOriginalIndex = $index;
  
  						// lines are stored 0-based in SourceMap spec version 3
  						$mapEncoded .= $this->encoder->encode($m['original_line'] - 1 - $lastOriginalLine);
  						$lastOriginalLine = $m['original_line'] - 1;
  
  						$mapEncoded .= $this->encoder->encode($m['original_column'] - $lastOriginalColumn);
  						$lastOriginalColumn = $m['original_column'];
  					}
  				}
  
  				$lineMapEncoded[] = $mapEncoded;
  			}
  
  			$groupedMapEncoded[] = implode(',', $lineMapEncoded) . ';';
  		}
  
  		return rtrim(implode($groupedMapEncoded), ';');
  	}
  
  	/**
  	 * Finds the index for the filename
  	 *
  	 * @param string $filename
  	 * @return integer|false
  	 */
  	protected function findFileIndex($filename){
  		return $this->source_keys[$filename];
  	}
  
  	/**
  	 * fix windows paths
  	 * @param  string $path
  	 * @return string      
  	 */
  	public function fixWindowsPath($path, $addEndSlash = false){
  		$slash = ($addEndSlash) ? '/' : '';
  		if( !empty($path) ){
  			$path = str_replace('\\', '/', $path);
  			$path = rtrim($path,'/') . $slash;
  		}
  
  		return $path;
  	}
  
  } 


Download modules/util/Less.php

History
Thu, 8 Oct 2020 21:47:46 +0200	Jan Dankert	Fix: Now compatible with PHP 7.4.
Sun, 4 Oct 2020 23:33:37 +0200	Jan Dankert	Fix: Now compatible with PHP 7.4.
Thu, 21 Nov 2019 21:32:30 +0100	Jan Dankert	Avoid weird PHP error message: break instead of continue.
Sat, 16 Dec 2017 23:21:31 +0100	Jan Dankert	Eigenes Modul für alle Util-Klassen.