Merge branch 'php-less-compiler'

3 files changed, 10841 insertions, 0 deletions

diff --git a/lib/less.php/Cache.php b/lib/less.php/Cache.php
new file mode 100644
index 0000000..8c8be39
--- /dev/null
+++ b/lib/less.php/Cache.php
@@ -0,0 +1,316 @@
+<?php
+
+require_once( dirname(__FILE__).'/Version.php');
+
+/**
+ * Utility for handling the generation and caching of css files
+ *
+ * @package Less
+ * @subpackage cache
+ *
+ */
+class Less_Cache{
+
+	// directory less.php can use for storing data
+	public static $cache_dir	= false;
+
+	// prefix for the storing data
+	public static $prefix		= 'lessphp_';
+
+	// prefix for the storing vars
+	public static $prefix_vars	= 'lessphpvars_';
+
+	// specifies the number of seconds after which data created by less.php will be seen as 'garbage' and potentially cleaned up
+	public static $gc_lifetime	= 604800;
+
+
+	/**
+	 * Save and reuse the results of compiled less files.
+	 * The first call to Get() will generate css and save it.
+	 * Subsequent calls to Get() with the same arguments will return the same css filename
+	 *
+	 * @param array $less_files Array of .less files to compile
+	 * @param array $parser_options Array of compiler options
+	 * @param array $modify_vars Array of variables
+	 * @return string Name of the css file
+	 */
+	public static function Get( $less_files, $parser_options = array(), $modify_vars = array() ){
+
+
+		//check $cache_dir
+		if( isset($parser_options['cache_dir']) ){
+			Less_Cache::$cache_dir = $parser_options['cache_dir'];
+		}
+
+		if( empty(Less_Cache::$cache_dir) ){
+			throw new Exception('cache_dir not set');
+		}
+
+		if( isset($parser_options['prefix']) ){
+			Less_Cache::$prefix = $parser_options['prefix'];
+		}
+
+		if( empty(Less_Cache::$prefix) ){
+			throw new Exception('prefix not set');
+		}
+
+		if( isset($parser_options['prefix_vars']) ){
+			Less_Cache::$prefix_vars = $parser_options['prefix_vars'];
+		}
+
+		if( empty(Less_Cache::$prefix_vars) ){
+			throw new Exception('prefix_vars not set');
+		}
+
+		self::CheckCacheDir();
+		$less_files = (array)$less_files;
+
+
+		//create a file for variables
+		if( !empty($modify_vars) ){
+			$lessvars = Less_Parser::serializeVars($modify_vars);
+			$vars_file = Less_Cache::$cache_dir . Less_Cache::$prefix_vars . sha1($lessvars) . '.less';
+
+			if( !file_exists($vars_file) ){
+				file_put_contents($vars_file, $lessvars);
+			}
+
+			$less_files += array($vars_file => '/');
+		}
+
+
+		// generate name for compiled css file
+		$hash = md5(json_encode($less_files));
+ 		$list_file = Less_Cache::$cache_dir . Less_Cache::$prefix . $hash . '.list';
+
+
+ 		// check cached content
+ 		if( !isset($parser_options['use_cache']) || $parser_options['use_cache'] === true ){
+			if( file_exists($list_file) ){
+
+				self::ListFiles($list_file, $list, $cached_name);
+				$compiled_name = self::CompiledName($list);
+
+				// if $cached_name is the same as the $compiled name, don't regenerate
+				if( !$cached_name || $cached_name === $compiled_name ){
+
+					$output_file = self::OutputFile($compiled_name, $parser_options );
+
+					if( $output_file && file_exists($output_file) ){
+						@touch($list_file);
+						return basename($output_file); // for backwards compatibility, we just return the name of the file
+					}
+				}
+			}
+		}
+
+		$compiled = self::Cache( $less_files, $parser_options );
+		if( !$compiled ){
+			return false;
+		}
+
+		$compiled_name = self::CompiledName( $less_files );
+		$output_file = self::OutputFile($compiled_name, $parser_options );
+
+
+		//save the file list
+		$list = $less_files;
+		$list[] = $compiled_name;
+		$cache = implode("\n",$list);
+		file_put_contents( $list_file, $cache );
+
+
+		//save the css
+		file_put_contents( $output_file, $compiled );
+
+
+		//clean up
+		self::CleanCache();
+
+		return basename($output_file);
+	}
+
+	/**
+	 * Force the compiler to regenerate the cached css file
+	 *
+	 * @param array $less_files Array of .less files to compile
+	 * @param array $parser_options Array of compiler options
+	 * @param array $modify_vars Array of variables
+	 * @return string Name of the css file
+	 */
+	public static function Regen( $less_files, $parser_options = array(), $modify_vars = array() ){
+		$parser_options['use_cache'] = false;
+		return self::Get( $less_files, $parser_options, $modify_vars );
+	}
+
+	public static function Cache( &$less_files, $parser_options = array() ){
+
+
+		// get less.php if it exists
+		$file = dirname(__FILE__) . '/Less.php';
+		if( file_exists($file) && !class_exists('Less_Parser') ){
+			require_once($file);
+		}
+
+		$parser_options['cache_dir'] = Less_Cache::$cache_dir;
+		$parser = new Less_Parser($parser_options);
+
+
+		// combine files
+		foreach($less_files as $file_path => $uri_or_less ){
+
+			//treat as less markup if there are newline characters
+			if( strpos($uri_or_less,"\n") !== false ){
+				$parser->Parse( $uri_or_less );
+				continue;
+			}
+
+			$parser->ParseFile( $file_path, $uri_or_less );
+		}
+
+		$compiled = $parser->getCss();
+
+
+		$less_files = $parser->allParsedFiles();
+
+		return $compiled;
+	}
+
+
+	private static function OutputFile( $compiled_name, $parser_options ){
+
+		//custom output file
+		if( !empty($parser_options['output']) ){
+
+			//relative to cache directory?
+			if( preg_match('#[\\\\/]#',$parser_options['output']) ){
+				return $parser_options['output'];
+			}
+
+			return Less_Cache::$cache_dir.$parser_options['output'];
+		}
+
+		return Less_Cache::$cache_dir.$compiled_name;
+	}
+
+
+	private static function CompiledName( $files ){
+
+		//save the file list
+		$temp = array(Less_Version::cache_version);
+		foreach($files as $file){
+			$temp[] = filemtime($file)."\t".filesize($file)."\t".$file;
+		}
+
+		return Less_Cache::$prefix.sha1(json_encode($temp)).'.css';
+	}
+
+
+	public static function SetCacheDir( $dir ){
+		Less_Cache::$cache_dir = $dir;
+	}
+
+	public static function CheckCacheDir(){
+
+		Less_Cache::$cache_dir = str_replace('\\','/',Less_Cache::$cache_dir);
+		Less_Cache::$cache_dir = rtrim(Less_Cache::$cache_dir,'/').'/';
+
+		if( !file_exists(Less_Cache::$cache_dir) ){
+			if( !mkdir(Less_Cache::$cache_dir) ){
+				throw new Less_Exception_Parser('Less.php cache directory couldn\'t be created: '.Less_Cache::$cache_dir);
+			}
+
+		}elseif( !is_dir(Less_Cache::$cache_dir) ){
+			throw new Less_Exception_Parser('Less.php cache directory doesn\'t exist: '.Less_Cache::$cache_dir);
+
+		}elseif( !is_writable(Less_Cache::$cache_dir) ){
+			throw new Less_Exception_Parser('Less.php cache directory isn\'t writable: '.Less_Cache::$cache_dir);
+
+		}
+
+	}
+
+
+	/**
+	 * Delete unused less.php files
+	 *
+	 */
+	public static function CleanCache(){
+		static $clean = false;
+
+		if( $clean ){
+			return;
+		}
+
+		$files = scandir(Less_Cache::$cache_dir);
+		if( $files ){
+			$check_time = time() - self::$gc_lifetime;
+			foreach($files as $file){
+
+				// don't delete if the file wasn't created with less.php
+				if( strpos($file,Less_Cache::$prefix) !== 0 ){
+					continue;
+				}
+
+				$full_path = Less_Cache::$cache_dir . $file;
+
+				// make sure the file still exists
+				// css files may have already been deleted
+				if( !file_exists($full_path) ){
+					continue;
+				}
+				$mtime = filemtime($full_path);
+
+				// don't delete if it's a relatively new file
+				if( $mtime > $check_time ){
+					continue;
+				}
+
+				$parts = explode('.',$file);
+				$type = array_pop($parts);
+
+
+				// delete css files based on the list files
+				if( $type === 'css' ){
+					continue;
+				}
+
+
+				// delete the list file and associated css file
+				if( $type === 'list' ){
+					self::ListFiles($full_path, $list, $css_file_name);
+					if( $css_file_name ){
+						$css_file = Less_Cache::$cache_dir . $css_file_name;
+						if( file_exists($css_file) ){
+							unlink($css_file);
+						}
+					}
+				}
+
+				unlink($full_path);
+			}
+		}
+
+		$clean = true;
+	}
+
+
+	/**
+	 * Get the list of less files and generated css file from a list file
+	 *
+	 */
+	static function ListFiles($list_file, &$list, &$css_file_name ){
+
+		$list = explode("\n",file_get_contents($list_file));
+
+		//pop the cached name that should match $compiled_name
+		$css_file_name = array_pop($list);
+
+		if( !preg_match('/^' . Less_Cache::$prefix . '[a-f0-9]+\.css$/',$css_file_name) ){
+			$list[] = $css_file_name;
+			$css_file_name = false;
+		}
+
+	}
+
+}
diff --git a/lib/less.php/Less.php b/lib/less.php/Less.php
new file mode 100644
index 0000000..69122e1
--- /dev/null
+++ b/lib/less.php/Less.php
@@ -0,0 +1,10510 @@
+<?php
+
+require_once( dirname(__FILE__).'/Cache.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'				=> array(),			// 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,
+
+		'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)/');
+		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('\\', '/', $path);
+	}
+
+	public function CacheEnabled(){
+		return (Less_Parser::$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 (!$color instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The first argument to argb must be a color' . ($dark 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' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
+		}
+		if (!$color2 instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The second argument to multiply must be a color' . ($color 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' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
+		}
+		if (!$color2 instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The second argument to screen must be a color' . ($color 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' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
+		}
+		if (!$color2 instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The second argument to overlay must be a color' . ($color 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' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
+		}
+		if (!$color2 instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The second argument to softlight must be a color' . ($color 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' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
+		}
+		if (!$color2 instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The second argument to hardlight must be a color' . ($color 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' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
+		}
+		if (!$color2 instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The second argument to difference must be a color' . ($color 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' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
+		}
+		if (!$color2 instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The second argument to exclusion must be a color' . ($color 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' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
+		}
+		if (!$color2 instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The second argument to average must be a color' . ($color 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' . ($color instanceof Less_Tree_Expression ? ' (did you forgot commas?)' : '') );
+		}
+		if (!$color2 instanceof Less_Tree_Color) {
+			throw new Less_Exception_Compiler('The second argument to negation must be a color' . ($color 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
+		$tabSetStr = "\n".str_repeat( '  ' , Less_Environment::$tabLevel-1 );
+		$tabRuleStr = $tabSetStr.'  ';
+
+		$output->add( " {" );
+		for($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 );
+		}
+
+
+		// 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 $type = 'NameValue';
+
+	public function __construct($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[': ']
+			. $this->value
+			. (((Less_Environment::$lastRule && Less_Parser::$options['compress'])) ? "" : ";")
+			, $this->currentFileInfo, $this->index);
+	}
+
+	public function compile ($env){
+		return $this;
+	}
+}
+ 
+
+/**
+ * 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 ){
+				$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 ){
+				$tabRuleStr = "\n".str_repeat( '  ' , Less_Environment::$tabLevel );
+				$tabSetStr = "\n".str_repeat( '  ' , Less_Environment::$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;

+					continue;

+

+				// )

+				case 41:

+					$parenLevel--;

+					if( $parenLevel < 0 ){

+						return $this->fail("missing opening `(`");

+					}

+					continue;

+

+				// ;

+				case 59:

+					//if (!$parenLevel) { $this->emitChunk();	}

+					continue;

+

+				// {

+				case 123:

+					$level++;

+					$lastOpening = $this->parserCurrentIndex;

+					continue;

+

+				// }

+				case 125:

+					$level--;

+					if( $level < 0 ){

+						return $this->fail("missing opening `{`");

+

+					}

+					//if (!$level && !$parenLevel) { $this->emitChunk(); }

+					continue;

+				// \

+				case 92:

+					if ($this->parserCurrentIndex < $this->input_len - 1) { $this->parserCurrentIndex++; continue; }

+					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) { continue; }

+					return $this->fail("unmatched `" + chr($cc) + "`", $currentChunkStartIndex);

+

+				// /, check for comment

+				case 47:

+					if ($parenLevel || ($this->parserCurrentIndex == $this->input_len - 1)) { continue; }

+					$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);

+						}

+					}

+					continue;

+

+				// *, check for unmatched */

+				case 42:

+					if (($this->parserCurrentIndex < $this->input_len - 1) && ($this->CharCode($this->parserCurrentIndex+1) == 47)) {

+						return $this->fail("unmatched `/*`");

+					}

+					continue;

+			}

+		}

+

+		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, $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;

+	}

+

+} 
\ No newline at end of file
diff --git a/lib/less.php/Version.php b/lib/less.php/Version.php
new file mode 100644
index 0000000..704ec6e
--- /dev/null
+++ b/lib/less.php/Version.php
@@ -0,0 +1,15 @@
+<?php
+
+/**
+ * Release numbers
+ *
+ * @package Less
+ * @subpackage version
+ */
+class Less_Version{
+
+	const version = '1.7.0.9';			// The current build number of less.php
+	const less_version = '1.7';			// The less.js version that this build should be compatible with
+    const cache_version = '170';		// The parser cache version
+
+}