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 ){
			$filename = self::AbsPath($filename, true);
		}
		$uri_root = self::WinPath($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;
	}