From 723c3144eca0bd3e5e340b6f4ad04f24099e2801 Mon Sep 17 00:00:00 2001
From: Mike Jolley <mike.jolley@me.com>
Date: Mon, 15 Oct 2012 11:38:37 +0100
Subject: [PATCH] [3.2.2] Updated lessc. #1575.

---
 admin/includes/class-lessc.php | 4016 +++++++++++++++++++-------------
 1 file changed, 2340 insertions(+), 1676 deletions(-)

diff --git a/admin/includes/class-lessc.php b/admin/includes/class-lessc.php
index 747ce5d10bd..452c502d379 100644
--- a/admin/includes/class-lessc.php
+++ b/admin/includes/class-lessc.php
@@ -1,332 +1,70 @@
 <?php
 /**
- * lessphp v0.3.4-2
+ * lessphp v0.3.8
  * http://leafo.net/lessphp
  *
  * LESS css compiler, adapted from http://lesscss.org
  *
  * Copyright 2012, Leaf Corcoran <leafot@gmail.com>
  * Licensed under MIT or GPLv3, see LICENSE
- *
- * @package LessPHP
  */
 
-if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly
 
 /**
  * The less compiler and parser.
  *
- * Converting LESS to CSS is a two stage process. First the incoming document
- * must be parsed. Parsing creates a tree in memory that represents the
- * structure of the document. Then, the tree of the document is recursively
- * compiled into the CSS text. The compile step has an implicit step called
- * reduction, where values are brought to their lowest form before being
- * turned to text, eg. mathematical equations are solved, and variables are
- * dereferenced.
+ * Converting LESS to CSS is a three stage process. The incoming file is parsed
+ * by `lessc_parser` into a syntax tree, then it is compiled into another tree
+ * representing the CSS structure by `lessc`. The CSS tree is fed into a
+ * formatter, like `lessc_formatter` which then outputs CSS as a string.
  *
- * The parsing stage produces the final structure of the document, for this
- * reason mixins are mixed in and attribute accessors are referenced during
- * the parse step. A reduction is done on the mixed in block as it is mixed in.
+ * During the first compile, all values are *reduced*, which means that their
+ * types are brought to the lowest form before being dump as strings. This
+ * handles math equations, variable dereferences, and the like.
  *
- *  See the following:
- *    - entry point for parsing and compiling: lessc::parse()
- *    - parsing: lessc::parseChunk()
- *    - compiling: lessc::compileBlock()
+ * The `parse` function of `lessc` is the entry point.
  *
+ * In summary:
+ *
+ * The `lessc` class creates an intstance of the parser, feeds it LESS code,
+ * then transforms the resulting tree to a CSS tree. This class also holds the
+ * evaluation context, such as all available mixins and variables at any given
+ * time.
+ *
+ * The `lessc_parser` class is only concerned with parsing its input.
+ *
+ * The `lessc_formatter` takes a CSS tree, and dumps it to a formatted string,
+ * handling things like indentation.
  */
 class lessc {
-	public static $VERSION = "v0.3.4-2";
-	protected $buffer;
-	protected $count;
-	protected $line;
-	protected $libFunctions = array();
-	static protected $nextBlockId = 0;
-
+	static public $VERSION = "v0.3.8";
 	static protected $TRUE = array("keyword", "true");
 	static protected $FALSE = array("keyword", "false");
 
-	public $indentLevel;
-	public $indentChar = '  ';
-
-	protected $env = null;
-
-	protected $allParsedFiles = array();
+	protected $libFunctions = array();
+	protected $registeredVars = array();
+	protected $preserveComments = false;
 
 	public $vPrefix = '@'; // prefix of abstract properties
 	public $mPrefix = '$'; // prefix of abstract blocks
-	public $imPrefix = '!'; // special character to add !important
 	public $parentSelector = '&';
 
-	// set to the parser that generated the current line when compiling
-	// so we know how to create error messages
-	protected $sourceParser = null;
-
-	static protected $precedence = array(
-		'=<' => 0,
-		'>=' => 0,
-		'=' => 0,
-		'<' => 0,
-		'>' => 0,
-
-		'+' => 1,
-		'-' => 1,
-		'*' => 2,
-		'/' => 2,
-		'%' => 2,
-	);
-	static protected $operatorString; // regex string to match any of the operators
-
-	// types that have delayed computation
-	static protected $dtypes = array('expression', 'variable',
-		'function', 'negative', 'list', 'lookup');
-
-	// these properties will supress division unless it's inside parenthases
-	static protected $supressDivisionProps = array('/border-radius$/i', '/^font$/i');
-
-	/**
-	 * @link http://www.w3.org/TR/css3-values/
-	 */
-	static protected $units = array(
-		'em', 'ex', 'px', 'gd', 'rem', 'vw', 'vh', 'vm', 'ch', // Relative length units
-		'in', 'cm', 'mm', 'pt', 'pc', // Absolute length units
-		'%', // Percentages
-		'deg', 'grad', 'rad', 'turn', // Angles
-		'ms', 's', // Times
-		'Hz', 'kHz', //Frequencies
-	);
-
 	public $importDisabled = false;
 	public $importDir = '';
 
-	public $compat = false; // lessjs compatibility mode, does nothing right now
+	protected $numberPrecision = null;
 
-	/**
-	 * if we are in an expression then we don't need to worry about parsing font shorthand
-	 * $inExp becomes true after the first value in an expression, or if we enter parens
-	 */
-	protected $inExp = false;
+	// set to the parser that generated the current line when compiling
+	// so we know how to create error messages
+	protected $sourceParser = null;
+	protected $sourceLoc = null;
 
-	/**
-	 * if we are in parens we can be more liberal with whitespace around operators because
-	 * it must evaluate to a single value and thus is less ambiguous.
-	 *
-	 * Consider:
-	 *     property1: 10 -5; // is two numbers, 10 and -5
-	 *     property2: (10 -5); // should evaluate to 5
-	 */
-	protected $inParens = false;
+	static public $defaultValue = array("keyword", "");
 
-	/**
-	 * Parse a single chunk off the head of the buffer and place it.
-	 * @return false when the buffer is empty, or when there is an error.
-	 *
-	 * This function is called repeatedly until the entire document is
-	 * parsed.
-	 *
-	 * This parser is most similar to a recursive descent parser. Single
-	 * functions represent discrete grammatical rules for the language, and
-	 * they are able to capture the text that represents those rules.
-	 *
-	 * Consider the function lessc::keyword(). (all parse functions are
-	 * structured the same)
-	 *
-	 * The function takes a single reference argument. When calling the
-	 * function it will attempt to match a keyword on the head of the buffer.
-	 * If it is successful, it will place the keyword in the referenced
-	 * argument, advance the position in the buffer, and return true. If it
-	 * fails then it won't advance the buffer and it will return false.
-	 *
-	 * All of these parse functions are powered by lessc::match(), which behaves
-	 * the same way, but takes a literal regular expression. Sometimes it is
-	 * more convenient to use match instead of creating a new function.
-	 *
-	 * Because of the format of the functions, to parse an entire string of
-	 * grammatical rules, you can chain them together using &&.
-	 *
-	 * But, if some of the rules in the chain succeed before one fails, then
-	 * the buffer position will be left at an invalid state. In order to
-	 * avoid this, lessc::seek() is used to remember and set buffer positions.
-	 *
-	 * Before parsing a chain, use $s = $this->seek() to remember the current
-	 * position into $s. Then if a chain fails, use $this->seek($s) to
-	 * go back where we started.
-	 */
-	function parseChunk() {
-		if (empty($this->buffer)) return false;
-		$s = $this->seek();
-
-		// setting a property
-		if ($this->keyword($key) && $this->assign() &&
-			$this->propertyValue($value, $key) && $this->end())
-		{
-			$this->append(array('assign', $key, $value), $s);
-			return true;
-		} else {
-			$this->seek($s);
-		}
-
-		// look for special css blocks
-		if ($this->env->parent == null && $this->literal('@', false)) {
-			$this->count--;
-
-			// a font-face block
-			if ($this->literal('@font-face') && $this->literal('{')) {
-				$b = $this->pushSpecialBlock('@font-face');
-				return true;
-			} else {
-				$this->seek($s);
-			}
-
-			// charset
-			if ($this->literal('@charset') && $this->propertyValue($value) &&
-				$this->end())
-			{
-				$this->append(array('charset', $value), $s);
-				return true;
-			} else {
-				$this->seek($s);
-			}
-
-
-			// media
-			if ($this->literal('@media') && $this->mediaTypes($types) &&
-				$this->literal('{'))
-			{
-				$b = $this->pushSpecialBlock('@media');
-				$b->media = $types;
-				return true;
-			} else {
-				$this->seek($s);
-			}
-
-			// css animations
-			if ($this->match('(@(-[a-z]+-)?keyframes)', $m) &&
-				$this->propertyValue($value) && $this->literal('{'))
-			{
-				$b = $this->pushSpecialBlock(trim($m[0]));
-				$b->keyframes = $value;
-				return true;
-			} else {
-				$this->seek($s);
-			}
-		}
-
-		if (isset($this->env->keyframes)) {
-			if ($this->match("(to|from|[0-9]+%)", $m) && $this->literal('{')) {
-				$this->pushSpecialBlock($m[1]);
-				return true;
-			} else {
-				$this->seek($s);
-			}
-		}
-
-		// setting a variable
-		if ($this->variable($var) && $this->assign() &&
-			$this->propertyValue($value) && $this->end())
-		{
-			$this->append(array('assign', $var, $value), $s);
-			return true;
-		} else {
-			$this->seek($s);
-		}
-
-		if ($this->import($url, $media)) {
-			// don't check .css files
-			if (empty($media) && substr_compare($url, '.css', -4, 4) !== 0) {
-				if ($this->importDisabled) {
-					$this->append(array('raw', '/* import disabled */'));
-				} else {
-					$path = $this->findImport($url);
-					if (!is_null($path)) {
-						$this->append(array('import', $path), $s);
-						return true;
-					}
-				}
-			}
-
-			$this->append(array('raw', '@import url("'.$url.'")'.
-				($media ? ' '.$media : '').';'), $s);
-			return true;
-		}
-
-		// opening parametric mixin
-		if ($this->tag($tag, true) && $this->argumentDef($args, $is_vararg) &&
-			($this->guards($guards) || true) &&
-			$this->literal('{'))
-		{
-			$block = $this->pushBlock($this->fixTags(array($tag)));
-			$block->args = $args;
-			$block->is_vararg = $is_vararg;
-			if (!empty($guards)) $block->guards = $guards;
-			return true;
-		} else {
-			$this->seek($s);
-		}
-
-		// opening a simple block
-		if ($this->tags($tags) && $this->literal('{')) {
-			$tags = $this->fixTags($tags);
-			$this->pushBlock($tags);
-			return true;
-		} else {
-			$this->seek($s);
-		}
-
-		// closing a block
-		if ($this->literal('}')) {
-			try {
-				$block = $this->pop();
-			} catch (exception $e) {
-				$this->seek($s);
-				$this->throwError($e->getMessage());
-			}
-
-			$hidden = true;
-			if (!isset($block->args)) foreach ($block->tags as $tag) {
-				if (!is_string($tag) || $tag{0} != $this->mPrefix) {
-					$hidden = false;
-					break;
-				}
-			}
-
-			if (!$hidden) $this->append(array('block', $block), $s);
-
-			foreach ($block->tags as $tag) {
-				if (is_string($tag)) {
-					$this->env->children[$tag][] = $block;
-				}
-			}
-
-			return true;
-		}
-
-		// mixin
-		if ($this->mixinTags($tags) &&
-			($this->argumentValues($argv) || true) && $this->end())
-		{
-			$tags = $this->fixTags($tags);
-			$this->append(array('mixin', $tags, $argv), $s);
-			return true;
-		} else {
-			$this->seek($s);
-		}
-
-		// spare ;
-		if ($this->literal(';')) return true;
-
-		return false; // got nothing, throw error
-	}
-
-	function fixTags($tags) {
-		// move @ tags out of variable namespace
-		foreach ($tags as &$tag) {
-			if ($tag{0} == $this->vPrefix) $tag[0] = $this->mPrefix;
-		}
-		return $tags;
-	}
+	static protected $nextImportId = 0; // uniquely identify imports
 
 	// attempts to find the path of an import url, returns null for css files
-	function findImport($url) {
+	protected function findImport($url) {
 		foreach ((array)$this->importDir as $dir) {
 			$full = $dir.(substr($dir, -1) != '/' ? '/' : '').$url;
 			if ($this->fileExists($file = $full.'.less') || $this->fileExists($file = $full)) {
@@ -337,720 +75,93 @@ class lessc {
 		return null;
 	}
 
-	function fileExists($name) {
-		// sym link workaround
-		return file_exists($name) || file_exists(realpath(preg_replace('/\w+\/\.\.\//', '', $name)));
+	protected function fileExists($name) {
+		return is_file($name);
 	}
 
-	// a list of expressions
-	function expressionList(&$exps) {
-		$values = array();
-
-		while ($this->expression($exp)) {
-			$values[] = $exp;
-		}
-
-		if (count($values) == 0) return false;
-
-		$exps = $this->compressList($values, ' ');
-		return true;
-	}
-
-	/**
-	 * Attempt to consume an expression.
-	 * @link http://en.wikipedia.org/wiki/Operator-precedence_parser#Pseudo-code
-	 */
-	function expression(&$out) {
-		$s = $this->seek();
-		if ($this->literal('(') && ($this->inExp = $this->inParens = true) && $this->expression($exp) && $this->literal(')')) {
-			$lhs = $exp;
-		} elseif ($this->seek($s) && $this->value($val)) {
-			$lhs = $val;
-		} else {
-			$this->inParens = $this->inExp = false;
-			$this->seek($s);
-			return false;
-		}
-
-		$out = $this->expHelper($lhs, 0);
-		$this->inParens = $this->inExp = false;
-		return true;
-	}
-
-	/**
-	 * recursively parse infix equation with $lhs at precedence $minP
-	 */
-	function expHelper($lhs, $minP) {
-		$this->inExp = true;
-		$ss = $this->seek();
-
-		// if there was whitespace before the operator, then we require whitespace after
-		// the operator for it to be a mathematical operator.
-
-		$needWhite = false;
-		if (!$this->inParens && preg_match('/\s/', $this->buffer{$this->count - 1})) {
-			$needWhite = true;
-		}
-
-		// try to find a valid operator
-		while ($this->match(self::$operatorString.($needWhite ? '\s' : ''), $m) && self::$precedence[$m[1]] >= $minP) {
-			if (!$this->inParens && isset($this->env->currentProperty) && $m[1] == "/") {
-				foreach (self::$supressDivisionProps as $pattern) {
-					if (preg_match($pattern, $this->env->currentProperty)) {
-						$this->env->supressedDivision = true;
-						break 2;
-					}
-				}
-			}
-
-			// get rhs
-			$s = $this->seek();
-			$p = $this->inParens;
-			if ($this->literal('(') && ($this->inParens = true) && $this->expression($exp) && $this->literal(')')) {
-				$this->inParens = $p;
-				$rhs = $exp;
-			} else {
-				$this->inParens = $p;
-				if ($this->seek($s) && $this->value($val)) {
-					$rhs = $val;
-				} else {
-					break;
-				}
-			}
-
-			// peek for next operator to see what to do with rhs
-			if ($this->peek(self::$operatorString, $next) && self::$precedence[$next[1]] > self::$precedence[$m[1]]) {
-				$rhs = $this->expHelper($rhs, self::$precedence[$next[1]]);
-			}
-
-			// don't evaluate yet if it is dynamic
-			if (in_array($rhs[0], self::$dtypes) || in_array($lhs[0], self::$dtypes))
-				$lhs = array('expression', $m[1], $lhs, $rhs);
-			else
-				$lhs = $this->evaluate($m[1], $lhs, $rhs);
-
-			$ss = $this->seek();
-
-			$needWhite = false;
-			if (!$this->inParens && preg_match('/\s/', $this->buffer{$this->count - 1})) {
-				$needWhite = true;
-			}
-		}
-		$this->seek($ss);
-
-		return $lhs;
-	}
-
-	// consume a list of values for a property
-	function propertyValue(&$value, $keyName=null) {
-		$values = array();
-
-		if (!is_null($keyName)) $this->env->currentProperty = $keyName;
-
-		$s = null;
-		while ($this->expressionList($v)) {
-			$values[] = $v;
-			$s = $this->seek();
-			if (!$this->literal(',')) break;
-		}
-
-		if ($s) $this->seek($s);
-
-		if (!is_null($keyName)) unset($this->env->currentProperty);
-
-		if (count($values) == 0) return false;
-
-		$value = $this->compressList($values, ', ');
-		return true;
-	}
-
-	// a single value
-	function value(&$value) {
-		// try a unit
-		if ($this->unit($value)) return true;
-
-		// see if there is a negation
-		$s = $this->seek();
-		if ($this->literal('-', false)) {
-			$value = null;
-			if ($this->variable($var)) {
-				$value = array('variable', $var);
-			} elseif ($this->buffer{$this->count} == "(" && $this->expression($exp)) {
-				$value = $exp;
-			} else {
-				$this->seek($s);
-			}
-
-			if (!is_null($value)) {
-				$value = array('negative', $value);
-				return true;
-			}
-		} else {
-			$this->seek($s);
-		}
-
-		// accessor
-		// must be done before color
-		// this needs negation too
-		if ($this->accessor($a)) {
-			$a[1] = $this->fixTags($a[1]);
-			$value = $a;
-			return true;
-		}
-
-		// color
-		if ($this->color($value)) return true;
-
-		// css function
-		// must be done after color
-		if ($this->func($value)) return true;
-
-		// string
-		if ($this->string($tmp, $d)) {
-			$value = array('string', $d.$tmp.$d);
-			return true;
-		}
-
-		// try a keyword
-		if ($this->keyword($word)) {
-			$value = array('keyword', $word);
-			return true;
-		}
-
-		// try a variable
-		if ($this->variable($var)) {
-			$value = array('variable', $var);
-			return true;
-		}
-
-		// unquote string
-		if ($this->literal("~") && $this->string($value, $d)) {
-			$value = array("escape", $value);
-			return true;
-		} else {
-			$this->seek($s);
-		}
-
-		// css hack: \0
-		if ($this->literal('\\') && $this->match('([0-9]+)', $m)) {
-			$value = array('keyword', '\\'.$m[1]);
-			return true;
-		} else {
-			$this->seek($s);
-		}
-
-		// the spare / when supressing division
-		if (!empty($this->env->supressedDivision)) {
-			unset($this->env->supressedDivision);
-			if ($this->literal("/")) {
-				$value = array('keyword', '/');
-				return true;
-			}
-		}
-
-		return false;
-	}
-
-	// an import statement
-	function import(&$url, &$media) {
-		$s = $this->seek();
-		if (!$this->literal('@import')) return false;
-
-		// @import "something.css" media;
-		// @import url("something.css") media;
-		// @import url(something.css) media;
-
-		if ($this->literal('url(')) $parens = true; else $parens = false;
-
-		if (!$this->string($url)) {
-			if ($parens && $this->to(')', $url)) {
-				$parens = false; // got em
-			} else {
-				$this->seek($s);
-				return false;
-			}
-		}
-
-		if ($parens && !$this->literal(')')) {
-			$this->seek($s);
-			return false;
-		}
-
-		// now the rest is media
-		return $this->to(';', $media, false, true);
-	}
-
-	// a list of media types, very lenient
-	function mediaTypes(&$parts) {
-		$parts = array();
-		while ($this->to("(", $chunk, false, "[^{]")) {
-			$parts[] = array('raw', $chunk."(");
-			$s = $this->seek();
-			if ($this->keyword($name) && $this->assign() &&
-				$this->propertyValue($value))
-			{
-				$parts[] = array('assign', $name, $value);
-			} else {
-				$this->seek($s);
-			}
-		}
-
-		if ($this->to('{', $rest, true, true)) {
-			$parts[] = array('raw', $rest);
-			return true;
-		}
-
-		$parts = null;
-		return false;
-	}
-
-	// a scoped value accessor
-	// .hello > @scope1 > @scope2['value'];
-	function accessor(&$var) {
-		$s = $this->seek();
-
-		if (!$this->tags($scope, true, '>') || !$this->literal('[')) {
-			$this->seek($s);
-			return false;
-		}
-
-		// either it is a variable or a property
-		// why is a property wrapped in quotes, who knows!
-		if ($this->variable($name)) {
-			// ~
-		} elseif ($this->literal("'") && $this->keyword($name) && $this->literal("'")) {
-			// .. $this->count is messed up if we wanted to test another access type
-		} else {
-			$this->seek($s);
-			return false;
-		}
-
-		if (!$this->literal(']')) {
-			$this->seek($s);
-			return false;
-		}
-
-		$var = array('lookup', $scope, $name);
-		return true;
-	}
-
-	// a string
-	function string(&$string, &$d = null) {
-		$s = $this->seek();
-		if ($this->literal('"', false)) {
-			$delim = '"';
-		} elseif ($this->literal("'", false)) {
-			$delim = "'";
-		} else {
-			return false;
-		}
-
-		if (!$this->to($delim, $string)) {
-			$this->seek($s);
-			return false;
-		}
-
-		$d = $delim;
-		return true;
-	}
-
-	/**
-	 * Consume a number and optionally a unit.
-	 * Can also consume a font shorthand if it is a simple case.
-	 * $allowed restricts the types that are matched.
-	 */
-	function unit(&$unit, $allowed = null) {
-		if (!$allowed) $allowed = self::$units;
-
-		if ($this->match('(-?[0-9]*(\.)?[0-9]+)('.implode('|', $allowed).')?', $m)) {
-			if (!isset($m[3])) $m[3] = 'number';
-			$unit = array($m[3], $m[1]);
-
-			return true;
-		}
-
-		return false;
-	}
-
-	// a # color
-	function color(&$out) {
-		$color = array('color');
-
-		if ($this->match('(#([0-9a-f]{6})|#([0-9a-f]{3}))', $m)) {
-			if (isset($m[3])) {
-				$num = $m[3];
-				$width = 16;
-			} else {
-				$num = $m[2];
-				$width = 256;
-			}
-
-			$num = hexdec($num);
-			foreach (array(3,2,1) as $i) {
-				$t = $num % $width;
-				$num /= $width;
-
-				$color[$i] = $t * (256/$width) + $t * floor(16/$width);
-			}
-
-			$out = $color;
-			return true;
-		}
-
-		return false;
-	}
-
-	// consume a list of property values delimited by ; and wrapped in ()
-	function argumentValues(&$args, $delim = ',') {
-		$s = $this->seek();
-		if (!$this->literal('(')) return false;
-
-		$values = array();
-		while (true) {
-			if ($this->expressionList($value)) $values[] = $value;
-			if (!$this->literal($delim)) break;
-			else {
-				if ($value == null) $values[] = null;
-				$value = null;
-			}
-		}
-
-		if (!$this->literal(')')) {
-			$this->seek($s);
-			return false;
-		}
-
-		$args = $values;
-		return true;
-	}
-
-	// consume an argument definition list surrounded by ()
-	// each argument is a variable name with optional value
-	// or at the end a ... or a variable named followed by ...
-	function argumentDef(&$args, &$is_vararg, $delim = ',') {
-		$s = $this->seek();
-		if (!$this->literal('(')) return false;
-
-		$values = array();
-
-		$is_vararg = false;
-		while (true) {
-			if ($this->literal("...")) {
-				$is_vararg = true;
-				break;
-			}
-
-			if ($this->variable($vname)) {
-				$arg = array("arg", $vname);
-				$ss = $this->seek();
-				if ($this->assign() && $this->expressionList($value)) {
-					$arg[] = $value;
-				} else {
-					$this->seek($ss);
-					if ($this->literal("...")) {
-						$arg[0] = "rest";
-						$is_vararg = true;
-					}
-				}
-				$values[] = $arg;
-				if ($is_vararg) break;
-				continue;
-			}
-
-			if ($this->value($literal)) {
-				$values[] = array("lit", $literal);
-			}
-
-			if (!$this->literal($delim)) break;
-		}
-
-		if (!$this->literal(')')) {
-			$this->seek($s);
-			return false;
-		}
-
-		$args = $values;
-
-		return true;
-	}
-
-	// consume a list of tags
-	// this accepts a hanging delimiter
-	function tags(&$tags, $simple = false, $delim = ',') {
-		$tags = array();
-		while ($this->tag($tt, $simple)) {
-			$tags[] = $tt;
-			if (!$this->literal($delim)) break;
-		}
-		if (count($tags) == 0) return false;
-
-		return true;
-	}
-
-	// list of tags of specifying mixin path
-	// optionally separated by > (lazy, accepts extra >)
-	function mixinTags(&$tags) {
-		$s = $this->seek();
-		$tags = array();
-		while ($this->tag($tt, true)) {
-			$tags[] = $tt;
-			$this->literal(">");
-		}
-
-		if (count($tags) == 0) return false;
-
-		return true;
-	}
-
-	// a bracketed value (contained within in a tag definition)
-	function tagBracket(&$value) {
-		$s = $this->seek();
-		if ($this->literal('[') && $this->to(']', $c, true) && $this->literal(']', false)) {
-			$value = '['.$c.']';
-			// whitespace?
-			if ($this->match('', $_)) $value .= $_[0];
-
-			// escape parent selector
-			$value = str_replace($this->parentSelector, "&&", $value);
-			return true;
-		}
-
-		$this->seek($s);
-		return false;
-	}
-
-	function tagExpression(&$value) {
-		$s = $this->seek();
-		if ($this->literal("(") && $this->expression($exp) && $this->literal(")")) {
-			$value = array('exp', $exp);
-			return true;
-		}
-
-		$this->seek($s);
-		return false;
-	}
-
-	// a single tag
-	function tag(&$tag, $simple = false) {
-		if ($simple)
-			$chars = '^,:;{}\][>\(\) "\'';
-		else
-			$chars = '^,;{}["\'';
-
-		if (!$simple && $this->tagExpression($tag)) {
-			return true;
-		}
-
-		$tag = '';
-		while ($this->tagBracket($first)) $tag .= $first;
-		while ($this->match('(['.$chars.'0-9]['.$chars.']*)', $m)) {
-			$tag .= $m[1];
-			if ($simple) break;
-
-			while ($this->tagBracket($brack)) $tag .= $brack;
-		}
-		$tag = trim($tag);
-		if ($tag == '') return false;
-
-		return true;
-	}
-
-	// a css function
-	function func(&$func) {
-		$s = $this->seek();
-
-		if ($this->match('(%|[\w\-_][\w\-_:\.]+|[\w_])', $m) && $this->literal('(')) {
-			$fname = $m[1];
-
-			$s_pre_args = $this->seek();
-
-			$args = array();
-			while (true) {
-				$ss = $this->seek();
-				// this ugly nonsense is for ie filter properties
-				if ($this->keyword($name) && $this->literal('=') && $this->expressionList($value)) {
-					$args[] = array('list', '=', array(array('keyword', $name), $value));
-				} else {
-					$this->seek($ss);
-					if ($this->expressionList($value)) {
-						$args[] = $value;
-					}
-				}
-
-				if (!$this->literal(',')) break;
-			}
-			$args = array('list', ',', $args);
-
-			if ($this->literal(')')) {
-				$func = array('function', $fname, $args);
-				return true;
-			} elseif ($fname == 'url') {
-				// couldn't parse and in url? treat as string
-				$this->seek($s_pre_args);
-				if ($this->to(')', $content, true) && $this->literal(')')) {
-					$func = array('function', $fname,array('string', $content));
-					return true;
-				}
-			}
-		}
-
-		$this->seek($s);
-		return false;
-	}
-
-	// consume a less variable
-	function variable(&$name) {
-		$s = $this->seek();
-		if ($this->literal($this->vPrefix, false) &&
-			($this->variable($sub) || $this->keyword($name)))
-		{
-			if (!empty($sub)) {
-				$name = array('variable', $sub);
-			} else {
-				$name = $this->vPrefix.$name;
-			}
-			return true;
-		}
-
-		$name = null;
-		$this->seek($s);
-		return false;
-	}
-
-	/**
-	 * Consume an assignment operator
-	 * Can optionally take a name that will be set to the current property name
-	 */
-	function assign($name = null) {
-		if ($name) $this->currentProperty = $name;
-		return $this->literal(':') || $this->literal('=');
-	}
-
-	// consume a keyword
-	function keyword(&$word) {
-		if ($this->match('([\w_\-\*!"][\w\-_"]*)', $m)) {
-			$word = $m[1];
-			return true;
-		}
-		return false;
-	}
-
-	// consume an end of statement delimiter
-	function end() {
-		if ($this->literal(';'))
-			return true;
-		elseif ($this->count == strlen($this->buffer) || $this->buffer{$this->count} == '}') {
-			// if there is end of file or a closing block next then we don't need a ;
-			return true;
-		}
-		return false;
-	}
-
-	function guards(&$guards) {
-		$s = $this->seek();
-
-		if (!$this->literal("when")) {
-			$this->seek($s);
-			return false;
-		}
-
-		$guards = array();
-
-		while ($this->guard_group($g)) {
-			$guards[] = $g;
-			if (!$this->literal(",")) break;
-		}
-
-		if (count($guards) == 0) {
-			$guards = null;
-			$this->seek($s);
-			return false;
-		}
-
-		return true;
-	}
-
-	// a bunch of guards that are and'd together
-	function guard_group(&$guard_group) {
-		$s = $this->seek();
-		$guard_group = array();
-		while ($this->guard($guard)) {
-			$guard_group[] = $guard;
-			if (!$this->literal("and")) break;
-		}
-
-		if (count($guard_group) == 0) {
-			$guard_group = null;
-			$this->seek($s);
-			return false;
-		}
-
-		return true;
-	}
-
-	function guard(&$guard) {
-		$s = $this->seek();
-		$negate = $this->literal("not");
-
-		if ($this->literal("(") && $this->expression($exp) && $this->literal(")")) {
-			$guard = $exp;
-			if ($negate) $guard = array("negate", $guard);
-			return true;
-		}
-
-		$this->seek($s);
-		return false;
-	}
-
-	function compressList($items, $delim) {
-		if (count($items) == 1) return $items[0];
+	static public function compressList($items, $delim) {
+		if (!isset($items[1]) && isset($items[0])) return $items[0];
 		else return array('list', $delim, $items);
 	}
 
-	// just do a shallow property merge, seems to be what lessjs does
-	function mergeBlock($target, $from) {
-		$target = clone $target;
-		$target->props = array_merge($target->props, $from->props);
-		return $target;
+	static public function preg_quote($what) {
+		return preg_quote($what, '/');
 	}
 
-	// import all imports into the block
-	function mixImports($block) {
-		$props = array();
-		foreach ($block->props as $prop) {
-			if ($prop[0] == 'import') {
-				list(, $path) = $prop;
-				$this->addParsedFile($path);
-				$child_less = $this->createChild($path);
-				$root = $child_less->parseTree();
+	protected function tryImport($importPath, $parentBlock, $out) {
+		if ($importPath[0] == "function" && $importPath[1] == "url") {
+			$importPath = $this->flattenList($importPath[2]);
+		}
 
-				$root->parent = $block;
-				$this->mixImports($root);
+		$str = $this->coerceString($importPath);
+		if ($str === null) return false;
 
-				// inject imported blocks into this block, local will overwrite import
-				$block->children = array_merge($root->children, $block->children);
+		$url = $this->compileValue($this->lib_e($str));
 
-				// splice in all the props
-				foreach ($root->props as $sub_prop) {
-					if (isset($sub_prop[-1])) {
-						// leave a reference to the imported file for error messages
-						$sub_prop[-1] = array($child_less, $sub_prop[-1]);
-					}
-					$props[] = $sub_prop;
-				}
-			} else {
-				$props[] = $prop;
+		// don't import if it ends in css
+		if (substr_compare($url, '.css', -4, 4) === 0) return false;
+
+		$realPath = $this->findImport($url);
+		if ($realPath === null) return false;
+
+		if ($this->importDisabled) {
+			return array(false, "/* import disabled */");
+		}
+
+		$this->addParsedFile($realPath);
+		$parser = $this->makeParser($realPath);
+		$root = $parser->parse(file_get_contents($realPath));
+
+		// set the parents of all the block props
+		foreach ($root->props as $prop) {
+			if ($prop[0] == "block") {
+				$prop[1]->parent = $parentBlock;
 			}
 		}
-		$block->props = $props;
+
+		// copy mixins into scope, set their parents
+		// bring blocks from import into current block
+		// TODO: need to mark the source parser	these came from this file
+		foreach ($root->children as $childName => $child) {
+			if (isset($parentBlock->children[$childName])) {
+				$parentBlock->children[$childName] = array_merge(
+					$parentBlock->children[$childName],
+					$child);
+			} else {
+				$parentBlock->children[$childName] = $child;
+			}
+		}
+
+		$pi = pathinfo($realPath);
+		$dir = $pi["dirname"];
+
+		list($top, $bottom) = $this->sortProps($root->props, true);
+		$this->compileImportedProps($top, $parentBlock, $out, $parser, $dir);
+
+		return array(true, $bottom, $parser, $dir);
+	}
+
+	protected function compileImportedProps($props, $block, $out, $sourceParser, $importDir) {
+		$oldSourceParser = $this->sourceParser;
+
+		$oldImport = $this->importDir;
+
+		// TODO: this is because the importDir api is stupid
+		$this->importDir = (array)$this->importDir;
+		array_unshift($this->importDir, $importDir);
+
+		foreach ($props as $prop) {
+			$this->compileProp($prop, $block, $out);
+		}
+
+		$this->importDir = $oldImport;
+		$this->sourceParser = $oldSourceParser;
 	}
 
 	/**
 	 * Recursively compiles a block.
-	 * @param $block the block
-	 * @param $parentTags the tags of the block that contained this one
 	 *
-	 * A block is analogous to a CSS block in most cases. A single less document
+	 * A block is analogous to a CSS block in most cases. A single LESS document
 	 * is encapsulated in a block when parsed, but it does not have parent tags
 	 * so all of it's children appear on the root level when compiled.
 	 *
@@ -1060,6 +171,7 @@ class lessc {
 	 * to be taken, eg. write a property, set a variable, mixin a block.
 	 *
 	 * The children of a block are just all the blocks that are defined within.
+	 * This is used to look up mixins when performing a mixin.
 	 *
 	 * Compiling the block involves pushing a fresh environment on the stack,
 	 * and iterating through the props, compiling each one.
@@ -1067,134 +179,280 @@ class lessc {
 	 * See lessc::compileProp()
 	 *
 	 */
-	function compileBlock($block, $parent_tags = null) {
-		$isRoot = $parent_tags == null && $block->tags == null;
-
-		$indent = str_repeat($this->indentChar, $this->indentLevel);
-
-		if (!empty($block->no_multiply)) {
-			$special_block = true;
-			$this->indentLevel++;
-			$tags = array();
-		} else {
-			$special_block = false;
-
-			// evaluate expression tags
-			$tags = null;
-			if (is_array($block->tags)) {
-				$tags = array();
-				foreach ($block->tags as $tag) {
-					if (is_array($tag)) {
-						list(, $value) = $tag;
-						$tags[] = $this->compileValue($this->reduce($value));
-					} else {
-						$tags[] = $tag;
-					}
-				}
+	protected function compileBlock($block) {
+		switch ($block->type) {
+		case "root":
+			$this->compileRoot($block);
+			break;
+		case null:
+			$this->compileCSSBlock($block);
+			break;
+		case "media":
+			$this->compileMedia($block);
+			break;
+		case "directive":
+			$name = "@" . $block->name;
+			if (!empty($block->value)) {
+				$name .= " " . $this->compileValue($this->reduce($block->value));
 			}
 
-			$tags = $this->multiplyTags($parent_tags, $tags);
+			$this->compileNestedBlock($block, array($name));
+			break;
+		default:
+			$this->throwError("unknown block type: $block->type\n");
 		}
+	}
 
+	protected function compileCSSBlock($block) {
 		$env = $this->pushEnv();
-		$env->nameDepth = array();
 
-		$lines = array();
-		$blocks = array();
-		$this->mixImports($block);
-		foreach ($block->props as $prop) {
-			$this->compileProp($prop, $block, $tags, $lines, $blocks);
-		}
+		$selectors = $this->compileSelectors($block->tags);
+		$env->selectors = $this->multiplySelectors($selectors);
+		$out = $this->makeOutputBlock(null, $env->selectors);
 
-		$block->scope = $env;
+		$this->scope->children[] = $out;
+		$this->compileProps($block, $out);
 
-		$this->pop();
-
-		$nl = $isRoot ? "\n".$indent :
-			"\n".$indent.$this->indentChar;
-
-		ob_start();
-
-		if ($special_block) {
-			$this->indentLevel--;
-			if (isset($block->media)) {
-				echo $this->compileMedia($block);
-			} elseif (isset($block->keyframes)) {
-				echo $block->tags[0]." ".
-					$this->compileValue($this->reduce($block->keyframes));
-			} else {
-				list($name) = $block->tags;
-				echo $indent.$name;
-			}
-
-			echo ' {'.(count($lines) > 0 ? $nl : "\n");
-		}
-
-		// dump it
-		if (count($lines) > 0) {
-			if (!$special_block && !$isRoot) {
-				echo $indent.implode(", ", $tags);
-				if (count($lines) > 1) echo " {".$nl;
-				else echo " { ";
-			}
-
-			echo implode($nl, $lines);
-
-			if (!$special_block && !$isRoot) {
-				if (count($lines) > 1) echo "\n".$indent."}\n";
-				else echo " }\n";
-			} else echo "\n";
-		}
-
-		foreach ($blocks as $b) echo $b;
-
-		if ($special_block) {
-			echo $indent."}\n";
-		}
-
-		return ob_get_clean();
+		$block->scope = $env; // mixins carry scope with them!
+		$this->popEnv();
 	}
 
-	// find the fully qualified tags for a block and its parent's tags
-	function multiplyTags($parents, $current) {
-		if ($parents == null) return $current;
+	protected function compileMedia($media) {
+		$env = $this->pushEnv($media);
+		$parentScope = $this->mediaParent($this->scope);
 
-		$tags = array();
-		foreach ($parents as $ptag) {
-			foreach ($current as $tag) {
-				// inject parent in place of parent selector, ignoring escaped values
-				$count = 0;
-				$parts = explode("&&", $tag);
+		$query = $this->compileMediaQuery($this->multiplyMedia($env));
 
-				foreach ($parts as $i => $chunk) {
-					$parts[$i] = str_replace($this->parentSelector, $ptag, $chunk, $c);
-					$count += $c;
-				}
+		$this->scope = $this->makeOutputBlock($media->type, array($query));
+		$parentScope->children[] = $this->scope;
 
-				$tag = implode("&", $parts);
+		$this->compileProps($media, $this->scope);
 
-				if ($count > 0) {
-					$tags[] = trim($tag);
+		if (count($this->scope->lines) > 0) {
+			$orphanSelelectors = $this->findClosestSelectors();
+			if (!is_null($orphanSelelectors)) {
+				$orphan = $this->makeOutputBlock(null, $orphanSelelectors);
+				$orphan->lines = $this->scope->lines;
+				array_unshift($this->scope->children, $orphan);
+				$this->scope->lines = array();
+			}
+		}
+
+		$this->scope = $this->scope->parent;
+		$this->popEnv();
+	}
+
+	protected function mediaParent($scope) {
+		while (!empty($scope->parent)) {
+			if (!empty($scope->type) && $scope->type != "media") {
+				break;
+			}
+			$scope = $scope->parent;
+		}
+
+		return $scope;
+	}
+
+	protected function compileNestedBlock($block, $selectors) {
+		$this->pushEnv($block);
+		$this->scope = $this->makeOutputBlock($block->type, $selectors);
+		$this->scope->parent->children[] = $this->scope;
+
+		$this->compileProps($block, $this->scope);
+
+		$this->scope = $this->scope->parent;
+		$this->popEnv();
+	}
+
+	protected function compileRoot($root) {
+		$this->pushEnv();
+		$this->scope = $this->makeOutputBlock($root->type);
+		$this->compileProps($root, $this->scope);
+		$this->popEnv();
+	}
+
+	protected function compileProps($block, $out) {
+		foreach ($this->sortProps($block->props) as $prop) {
+			$this->compileProp($prop, $block, $out);
+		}
+	}
+
+	protected function sortProps($props, $split = false) {
+		$vars = array();
+		$imports = array();
+		$other = array();
+
+		foreach ($props as $prop) {
+			switch ($prop[0]) {
+			case "assign":
+				if (isset($prop[1][0]) && $prop[1][0] == $this->vPrefix) {
+					$vars[] = $prop;
 				} else {
-					$tags[] = trim($ptag . ' ' . $tag);
+					$other[] = $prop;
+				}
+				break;
+			case "import":
+				$id = self::$nextImportId++;
+				$prop[] = $id;
+				$imports[] = $prop;
+				$other[] = array("import_mixin", $id);
+				break;
+			default:
+				$other[] = $prop;
+			}
+		}
+
+		if ($split) {
+			return array(array_merge($vars, $imports), $other);
+		} else {
+			return array_merge($vars, $imports, $other);
+		}
+	}
+
+	protected function compileMediaQuery($queries) {
+		$compiledQueries = array();
+		foreach ($queries as $query) {
+			$parts = array();
+			foreach ($query as $q) {
+				switch ($q[0]) {
+				case "mediaType":
+					$parts[] = implode(" ", array_slice($q, 1));
+					break;
+				case "mediaExp":
+					if (isset($q[2])) {
+						$parts[] = "($q[1]: " .
+							$this->compileValue($this->reduce($q[2])) . ")";
+					} else {
+						$parts[] = "($q[1])";
+					}
+					break;
+				}
+			}
+
+			if (count($parts) > 0) {
+				$compiledQueries[] =  implode(" and ", $parts);
+			}
+		}
+
+		$out = "@media";
+		if (!empty($parts)) {
+			$out .= " " .
+				implode($this->formatter->selectorSeparator, $compiledQueries);
+		}
+		return $out;
+	}
+
+	protected function multiplyMedia($env, $childQueries = null) {
+		if (is_null($env) ||
+			!empty($env->block->type) && $env->block->type != "media")
+		{
+			return $childQueries;
+		}
+
+		// plain old block, skip
+		if (empty($env->block->type)) {
+			return $this->multiplyMedia($env->parent, $childQueries);
+		}
+
+		$out = array();
+		$queries = $env->block->queries;
+		if (is_null($childQueries)) {
+			$out = $queries;
+		} else {
+			foreach ($queries as $parent) {
+				foreach ($childQueries as $child) {
+					$out[] = array_merge($parent, $child);
 				}
 			}
 		}
 
-		return $tags;
+		return $this->multiplyMedia($env->parent, $out);
 	}
 
-	function eq($left, $right) {
+	protected function expandParentSelectors(&$tag, $replace) {
+		$parts = explode("$&$", $tag);
+		$count = 0;
+		foreach ($parts as &$part) {
+			$part = str_replace($this->parentSelector, $replace, $part, $c);
+			$count += $c;
+		}
+		$tag = implode($this->parentSelector, $parts);
+		return $count;
+	}
+
+	protected function findClosestSelectors() {
+		$env = $this->env;
+		$selectors = null;
+		while ($env !== null) {
+			if (isset($env->selectors)) {
+				$selectors = $env->selectors;
+				break;
+			}
+			$env = $env->parent;
+		}
+
+		return $selectors;
+	}
+
+
+	// multiply $selectors against the nearest selectors in env
+	protected function multiplySelectors($selectors) {
+		// find parent selectors
+
+		$parentSelectors = $this->findClosestSelectors();
+		if (is_null($parentSelectors)) {
+			// kill parent reference in top level selector
+			foreach ($selectors as &$s) {
+				$this->expandParentSelectors($s, "");
+			}
+
+			return $selectors;
+		}
+
+		$out = array();
+		foreach ($parentSelectors as $parent) {
+			foreach ($selectors as $child) {
+				$count = $this->expandParentSelectors($child, $parent);
+
+				// don't prepend the parent tag if & was used
+				if ($count > 0) {
+					$out[] = trim($child);
+				} else {
+					$out[] = trim($parent . ' ' . $child);
+				}
+			}
+		}
+
+		return $out;
+	}
+
+	// reduces selector expressions
+	protected function compileSelectors($selectors) {
+		$out = array();
+
+		foreach ($selectors as $s) {
+			if (is_array($s)) {
+				list(, $value) = $s;
+				$out[] = $this->compileValue($this->reduce($value));
+			} else {
+				$out[] = $s;
+			}
+		}
+
+		return $out;
+	}
+
+	protected function eq($left, $right) {
 		return $left == $right;
 	}
 
-	function patternMatch($block, $callingArgs) {
+	protected function patternMatch($block, $callingArgs) {
 		// match the guards if it has them
 		// any one of the groups must have all its guards pass for a match
 		if (!empty($block->guards)) {
-			$group_passed = false;
-			foreach ($block->guards as $guard_group) {
-				foreach ($guard_group as $guard) {
+			$groupPassed = false;
+			foreach ($block->guards as $guardGroup) {
+				foreach ($guardGroup as $guard) {
 					$this->pushEnv();
 					$this->zipSetArgs($block->args, $callingArgs);
 
@@ -1207,20 +465,20 @@ class lessc {
 					$passed = $this->reduce($guard) == self::$TRUE;
 					if ($negate) $passed = !$passed;
 
-					$this->pop();
+					$this->popEnv();
 
 					if ($passed) {
-						$group_passed = true;
+						$groupPassed = true;
 					} else {
-						$group_passed = false;
+						$groupPassed = false;
 						break;
 					}
 				}
 
-				if ($group_passed) break;
+				if ($groupPassed) break;
 			}
 
-			if (!$group_passed) {
+			if (!$groupPassed) {
 				return false;
 			}
 		}
@@ -1228,7 +486,7 @@ class lessc {
 		$numCalling = count($callingArgs);
 
 		if (empty($block->args)) {
-			return $block->is_vararg || $numCalling == 0;
+			return $block->isVararg || $numCalling == 0;
 		}
 
 		$i = -1; // no args
@@ -1252,7 +510,7 @@ class lessc {
 			}
 		}
 
-		if ($block->is_vararg) {
+		if ($block->isVararg) {
 			return true; // not having enough is handled above
 		} else {
 			$numMatched = $i + 1;
@@ -1261,7 +519,7 @@ class lessc {
 		}
 	}
 
-	function patternMatchAll($blocks, $callingArgs) {
+	protected function patternMatchAll($blocks, $callingArgs) {
 		$matches = null;
 		foreach ($blocks as $block) {
 			if ($this->patternMatch($block, $callingArgs)) {
@@ -1273,15 +531,15 @@ class lessc {
 	}
 
 	// attempt to find blocks matched by path and args
-	function findBlocks($search_in, $path, $args, $seen=array()) {
-		if ($search_in == null) return null;
-		if (isset($seen[$search_in->id])) return null;
-		$seen[$search_in->id] = true;
+	protected function findBlocks($searchIn, $path, $args, $seen=array()) {
+		if ($searchIn == null) return null;
+		if (isset($seen[$searchIn->id])) return null;
+		$seen[$searchIn->id] = true;
 
 		$name = $path[0];
 
-		if (isset($search_in->children[$name])) {
-			$blocks = $search_in->children[$name];
+		if (isset($searchIn->children[$name])) {
+			$blocks = $searchIn->children[$name];
 			if (count($path) == 1) {
 				$matches = $this->patternMatchAll($blocks, $args);
 				if (!empty($matches)) {
@@ -1290,20 +548,31 @@ class lessc {
 					return $matches;
 				}
 			} else {
-				return $this->findBlocks($blocks[0],
-					array_slice($path, 1), $args, $seen);
+				$matches = array();
+				foreach ($blocks as $subBlock) {
+					$subMatches = $this->findBlocks($subBlock,
+						array_slice($path, 1), $args, $seen);
+
+					if (!is_null($subMatches)) {
+						foreach ($subMatches as $sm) {
+							$matches[] = $sm;
+						}
+					}
+				}
+
+				return count($matches) > 0 ? $matches : null;
 			}
 		}
 
-		if ($search_in->parent === $search_in) return null;
-		return $this->findBlocks($search_in->parent, $path, $args, $seen);
+		if ($searchIn->parent === $searchIn) return null;
+		return $this->findBlocks($searchIn->parent, $path, $args, $seen);
 	}
 
 	// sets all argument names in $args to either the default value
 	// or the one passed in through $values
-	function zipSetArgs($args, $values) {
+	protected function zipSetArgs($args, $values) {
 		$i = 0;
-		$assigned_values = array();
+		$assignedValues = array();
 		foreach ($args as $a) {
 			if ($a[0] == "arg") {
 				if ($i < count($values) && !is_null($values[$i])) {
@@ -1314,7 +583,7 @@ class lessc {
 
 				$value = $this->reduce($value);
 				$this->set($a[1], $value);
-				$assigned_values[] = $value;
+				$assignedValues[] = $value;
 			}
 			$i++;
 		}
@@ -1326,24 +595,13 @@ class lessc {
 			$this->set($last[1], $this->reduce(array("list", " ", $rest)));
 		}
 
-		$this->env->arguments = $assigned_values;
+		$this->env->arguments = $assignedValues;
 	}
 
 	// compile a prop and update $lines or $blocks appropriately
-	function compileProp($prop, $block, $tags, &$_lines, &$_blocks) {
+	protected function compileProp($prop, $block, $out) {
 		// set error position context
-		if (isset($prop[-1])) {
-			if (is_array($prop[-1])) {
-				list($less, $count) = $prop[-1];
-				$parentParser = $this->sourceParser;
-				$this->sourceParser = $less;
-				$this->count = $count;
-			} else {
-				$this->count = $prop[-1];
-			}
-		} else {
-			$this->count = -1;
-		}
+		$this->sourceLoc = isset($prop[-1]) ? $prop[-1] : -1;
 
 		switch ($prop[0]) {
 		case 'assign':
@@ -1351,69 +609,104 @@ class lessc {
 			if ($name[0] == $this->vPrefix) {
 				$this->set($name, $value);
 			} else {
-				$_lines[] = "$name:".
-					$this->compileValue($this->reduce($value)).";";
+				$out->lines[] = $this->formatter->property($name,
+						$this->compileValue($this->reduce($value)));
 			}
 			break;
 		case 'block':
 			list(, $child) = $prop;
-			$_blocks[] = $this->compileBlock($child, $tags);
+			$this->compileBlock($child);
 			break;
 		case 'mixin':
-			list(, $path, $args) = $prop;
+			list(, $path, $args, $suffix) = $prop;
 
 			$args = array_map(array($this, "reduce"), (array)$args);
 			$mixins = $this->findBlocks($block, $path, $args);
-			if (is_null($mixins)) {
-				// echo "failed to find block: ".implode(" > ", $path)."\n";
+
+			if ($mixins === null) {
+				// fwrite(STDERR,"failed to find block: ".implode(" > ", $path)."\n");
 				break; // throw error here??
 			}
 
 			foreach ($mixins as $mixin) {
-				$old_scope = null;
+				$haveScope = false;
 				if (isset($mixin->parent->scope)) {
-					$old_scope = $this->env;
-					$this->env = $mixin->parent->scope;
+					$haveScope = true;
+					$mixinParentEnv = $this->pushEnv();
+					$mixinParentEnv->storeParent = $mixin->parent->scope;
 				}
 
-				$have_args = false;
+				$haveArgs = false;
 				if (isset($mixin->args)) {
-					$have_args = true;
+					$haveArgs = true;
 					$this->pushEnv();
 					$this->zipSetArgs($mixin->args, $args);
 				}
 
-				$old_parent = $mixin->parent;
+				$oldParent = $mixin->parent;
 				if ($mixin != $block) $mixin->parent = $block;
 
-				foreach ($mixin->props as $sub_prop) {
-					$this->compileProp($sub_prop, $mixin, $tags, $_lines, $_blocks);
+				foreach ($this->sortProps($mixin->props) as $subProp) {
+					if ($suffix !== null &&
+						$subProp[0] == "assign" &&
+						is_string($subProp[1]) &&
+						$subProp[1]{0} != $this->vPrefix)
+					{
+						$subProp[2] = array(
+							'list', ' ',
+							array($subProp[2], array('keyword', $suffix))
+						);
+					}
+
+					$this->compileProp($subProp, $mixin, $out);
 				}
 
-				$mixin->parent = $old_parent;
+				$mixin->parent = $oldParent;
 
-				if ($have_args) $this->pop();
-
-				if ($old_scope) {
-					$this->env = $old_scope;
-				}
+				if ($haveArgs) $this->popEnv();
+				if ($haveScope) $this->popEnv();
 			}
 
 			break;
 		case 'raw':
-			$_lines[] = $prop[1];
+			$out->lines[] = $prop[1];
 			break;
-		case 'charset':
-			list(, $value) = $prop;
-			$_lines[] = '@charset '.$this->compileValue($this->reduce($value)).';';
+		case "directive":
+			list(, $name, $value) = $prop;
+			$out->lines[] = "@$name " . $this->compileValue($this->reduce($value)).';';
+			break;
+		case "comment":
+			$out->lines[] = $prop[1];
+			break;
+		case "import";
+			list(, $importPath, $importId) = $prop;
+			$importPath = $this->reduce($importPath);
+
+			if (!isset($this->env->imports)) {
+				$this->env->imports = array();
+			}
+
+			$result = $this->tryImport($importPath, $block, $out);
+
+			$this->env->imports[$importId] = $result === false ?
+				array(false, "@import " . $this->compileValue($importPath).";") :
+				$result;
+
+			break;
+		case "import_mixin":
+			list(,$importId) = $prop;
+			$import = $this->env->imports[$importId];
+			if ($import[0] === false) {
+				$out->lines[] = $import[1];
+			} else {
+				list(, $bottom, $parser, $importDir) = $import;
+				$this->compileImportedProps($bottom, $block, $out, $parser, $importDir);
+			}
+
 			break;
 		default:
 			$this->throwError("unknown op: {$prop[0]}\n");
 		}
-
-		if (isset($parentParser)) {
-			$this->sourceParser = $parentParser;
-		}
 	}
 
 
@@ -1425,42 +718,42 @@ class lessc {
 	 *
 	 *     array(type, contents [, additional_contents]*)
 	 *
-	 * Will not work on non reduced values (expressions, variables, etc)
+	 * The input is expected to be reduced. This function will not work on
+	 * things like expressions and variables.
 	 */
-	function compileValue($value) {
+	protected function compileValue($value) {
 		switch ($value[0]) {
 		case 'list':
 			// [1] - delimiter
 			// [2] - array of values
 			return implode($value[1], array_map(array($this, 'compileValue'), $value[2]));
+		case 'raw_color':
+			if (!empty($this->formatter->compressColors)) {
+				return $this->compileValue($this->coerceColor($value));
+			}
+			return $value[1];
 		case 'keyword':
 			// [1] - the keyword
-		case 'number':
-			// [1] - the number
 			return $value[1];
-		case 'escape':
+		case 'number':
+			list(, $num, $unit) = $value;
+			// [1] - the number
+			// [2] - the unit
+			if ($this->numberPrecision !== null) {
+				$num = round($num, $this->numberPrecision);
+			}
+			return $num . $unit;
 		case 'string':
 			// [1] - contents of string (includes quotes)
-
-			// search for inline variables to replace
-			$replace = array();
-			if (preg_match_all('/'.$this->preg_quote($this->vPrefix).'\{([\w-_][0-9\w-_]*)\}/', $value[1], $m)) {
-				foreach ($m[1] as $name) {
-					if (!isset($replace[$name]))
-						$replace[$name] = $this->compileValue($this->reduce(array('variable', $this->vPrefix . $name)));
+			list(, $delim, $content) = $value;
+			foreach ($content as &$part) {
+				if (is_array($part)) {
+					$part = $this->compileValue($part);
 				}
 			}
-
-			foreach ($replace as $var=>$val) {
-				if ($this->quoted($val)) {
-					$val = substr($val, 1, -1);
-				}
-				$value[1] = str_replace($this->vPrefix. '{'.$var.'}', $val, $value[1]);
-			}
-
-			return $value[1];
+			return $delim . implode($content) . $delim;
 		case 'color':
-			// [1] - red component (either number for a %)
+			// [1] - red component (either number or a %)
 			// [2] - green component
 			// [3] - blue component
 			// [4] - optional alpha component
@@ -1472,164 +765,146 @@ class lessc {
 			if (count($value) == 5 && $value[4] != 1) { // rgba
 				return 'rgba('.$r.','.$g.','.$b.','.$value[4].')';
 			}
-			return sprintf("#%02x%02x%02x", $r, $g, $b);
+
+			$h = sprintf("#%02x%02x%02x", $r, $g, $b);
+
+			if (!empty($this->formatter->compressColors)) {
+				// Converting hex color to short notation (e.g. #003399 to #039)
+				if ($h[1] === $h[2] && $h[3] === $h[4] && $h[5] === $h[6]) {
+					$h = '#' . $h[1] . $h[3] . $h[5];
+				}
+			}
+
+			return $h;
+
 		case 'function':
-			// [1] - function name
-			// [2] - some array value representing arguments, either ['string', value] or ['list', ',', values[]]
-
-			// see if function evaluates to something else
-			$value = $this->reduce($value);
-			if ($value[0] == 'function') {
-				return $value[1].'('.$this->compileValue($value[2]).')';
-			}
-			else return $this->compileValue($value);
+			list(, $name, $args) = $value;
+			return $name.'('.$this->compileValue($args).')';
 		default: // assumed to be unit
-			return $value[1].$value[0];
+			$this->throwError("unknown value type: $value[0]");
 		}
 	}
 
-	function compileMedia($block) {
-		$mediaParts = array();
-		foreach ($block->media as $part) {
-			if ($part[0] == "raw") {
-				$mediaParts[] = $part[1];
-			} elseif ($part[0] == "assign") {
-				list(, $propName, $propVal) = $part;
-				$mediaParts[] = "$propName: ".
-					$this->compileValue($this->reduce($propVal));
-			}
-		}
-
-		return "@media ".trim(implode($mediaParts));
+	protected function lib_isnumber($value) {
+		return $this->toBool($value[0] == "number");
 	}
 
-	function lib_isnumber($value) {
-		return $this->toBool(is_numeric($value[1]));
-	}
-
-	function lib_isstring($value) {
+	protected function lib_isstring($value) {
 		return $this->toBool($value[0] == "string");
 	}
 
-	function lib_iscolor($value) {
+	protected function lib_iscolor($value) {
 		return $this->toBool($this->coerceColor($value));
 	}
 
-	function lib_iskeyword($value) {
+	protected function lib_iskeyword($value) {
 		return $this->toBool($value[0] == "keyword");
 	}
 
-	function lib_ispixel($value) {
-		return $this->toBool($value[0] == "px");
+	protected function lib_ispixel($value) {
+		return $this->toBool($value[0] == "number" && $value[2] == "px");
 	}
 
-	function lib_ispercentage($value) {
-		return $this->toBool($value[0] == "%");
+	protected function lib_ispercentage($value) {
+		return $this->toBool($value[0] == "number" && $value[2] == "%");
 	}
 
-	function lib_isem($value) {
-		return $this->toBool($value[0] == "em");
+	protected function lib_isem($value) {
+		return $this->toBool($value[0] == "number" && $value[2] == "em");
 	}
 
-	function lib_rgbahex($color) {
+	protected function lib_rgbahex($color) {
 		$color = $this->coerceColor($color);
 		if (is_null($color))
 			$this->throwError("color expected for rgbahex");
 
 		return sprintf("#%02x%02x%02x%02x",
-			isset($color[4]) ? $color[4]*255 : 0,
+			isset($color[4]) ? $color[4]*255 : 255,
 			$color[1],$color[2], $color[3]);
 	}
 
-	function lib_argb($color){
-            return $this->lib_rgbahex($color);
-        }
+	protected function lib_argb($color){
+		return $this->lib_rgbahex($color);
+	}
 
 	// utility func to unquote a string
-	function lib_e($arg) {
+	protected function lib_e($arg) {
 		switch ($arg[0]) {
 			case "list":
 				$items = $arg[2];
 				if (isset($items[0])) {
 					return $this->lib_e($items[0]);
 				}
-				return "";
+				return self::$defaultValue;
 			case "string":
-				$str = $this->compileValue($arg);
-				return substr($str, 1, -1);
+				$arg[1] = "";
+				return $arg;
+			case "keyword":
+				return $arg;
 			default:
-				return $this->compileValue($arg);
+				return array("keyword", $this->compileValue($arg));
 		}
 	}
 
-	function lib__sprintf($args) {
+	protected function lib__sprintf($args) {
 		if ($args[0] != "list") return $args;
 		$values = $args[2];
-		$source = $this->reduce(array_shift($values));
-		if ($source[0] != "string") {
-			return $source;
-		}
+		$string = array_shift($values);
+		$template = $this->compileValue($this->lib_e($string));
 
-		$str = $source[1];
 		$i = 0;
-		if (preg_match_all('/%[dsa]/', $str, $m)) {
+		if (preg_match_all('/%[dsa]/', $template, $m)) {
 			foreach ($m[0] as $match) {
-				$val = isset($values[$i]) ? $this->reduce($values[$i]) : array('keyword', '');
-				$i++;
-				switch ($match[1]) {
-				case "s":
-					if ($val[0] == "string") {
-						$rep = substr($val[1], 1, -1);
-						break;
-					}
-				default:
-					$rep = $this->compileValue($val);
+				$val = isset($values[$i]) ?
+					$this->reduce($values[$i]) : array('keyword', '');
+
+				// lessjs compat, renders fully expanded color, not raw color
+				if ($color = $this->coerceColor($val)) {
+					$val = $color;
 				}
-				$str = preg_replace('/'.$this->preg_quote($match).'/', $rep, $str, 1);
+
+				$i++;
+				$rep = $this->compileValue($this->lib_e($val));
+				$template = preg_replace('/'.self::preg_quote($match).'/',
+					$rep, $template, 1);
 			}
 		}
 
-		return array('string', $str);
+		$d = $string[0] == "string" ? $string[1] : '"';
+		return array("string", $d, array($template));
 	}
 
-	function lib_floor($arg) {
-		return array($arg[0], floor($arg[1]));
+	protected function lib_floor($arg) {
+		$value = $this->assertNumber($arg);
+		return array("number", floor($value), $arg[2]);
 	}
 
-	function lib_ceil($arg) {
-		return array($arg[0], ceil($arg[1]));
+	protected function lib_ceil($arg) {
+		$value = $this->assertNumber($arg);
+		return array("number", ceil($value), $arg[2]);
 	}
 
-	function lib_round($arg) {
-		return array($arg[0], round($arg[1]));
-	}
-
-	// is a string surrounded in quotes? returns the quoting char if true
-	function quoted($s) {
-		if (preg_match('/^("|\').*?\1$/', $s, $m))
-			return $m[1];
-		else return false;
+	protected function lib_round($arg) {
+		$value = $this->assertNumber($arg);
+		return array("number", round($value), $arg[2]);
 	}
 
 	/**
-	 * Helper function to get arguments for color functions.
-	 * Accepts invalid input, non colors interpreted as being black.
+	 * Helper function to get arguments for color manipulation functions.
+	 * takes a list that contains a color like thing and a percentage
 	 */
-	function colorArgs($args) {
+	protected function colorArgs($args) {
 		if ($args[0] != 'list' || count($args[2]) < 2) {
-			return array(array('color', 0, 0, 0));
+			return array(array('color', 0, 0, 0), 0);
 		}
 		list($color, $delta) = $args[2];
-		$color = $this->coerceColor($color);
-		if (is_null($color))
-			$color = array('color', 0, 0, 0);
-
+		$color = $this->assertColor($color);
 		$delta = floatval($delta[1]);
 
 		return array($color, $delta);
 	}
 
-	function lib_darken($args) {
+	protected function lib_darken($args) {
 		list($color, $delta) = $this->colorArgs($args);
 
 		$hsl = $this->toHSL($color);
@@ -1637,7 +912,7 @@ class lessc {
 		return $this->toRGB($hsl);
 	}
 
-	function lib_lighten($args) {
+	protected function lib_lighten($args) {
 		list($color, $delta) = $this->colorArgs($args);
 
 		$hsl = $this->toHSL($color);
@@ -1645,7 +920,7 @@ class lessc {
 		return $this->toRGB($hsl);
 	}
 
-	function lib_saturate($args) {
+	protected function lib_saturate($args) {
 		list($color, $delta) = $this->colorArgs($args);
 
 		$hsl = $this->toHSL($color);
@@ -1653,7 +928,7 @@ class lessc {
 		return $this->toRGB($hsl);
 	}
 
-	function lib_desaturate($args) {
+	protected function lib_desaturate($args) {
 		list($color, $delta) = $this->colorArgs($args);
 
 		$hsl = $this->toHSL($color);
@@ -1661,7 +936,7 @@ class lessc {
 		return $this->toRGB($hsl);
 	}
 
-	function lib_spin($args) {
+	protected function lib_spin($args) {
 		list($color, $delta) = $this->colorArgs($args);
 
 		$hsl = $this->toHSL($color);
@@ -1672,58 +947,57 @@ class lessc {
 		return $this->toRGB($hsl);
 	}
 
-	function lib_fadeout($args) {
+	protected function lib_fadeout($args) {
 		list($color, $delta) = $this->colorArgs($args);
 		$color[4] = $this->clamp((isset($color[4]) ? $color[4] : 1) - $delta/100);
 		return $color;
 	}
 
-	function lib_fadein($args) {
+	protected function lib_fadein($args) {
 		list($color, $delta) = $this->colorArgs($args);
 		$color[4] = $this->clamp((isset($color[4]) ? $color[4] : 1) + $delta/100);
 		return $color;
 	}
 
-	function lib_hue($color) {
-		if ($color[0] != 'color') return 0;
-		$hsl = $this->toHSL($color);
+	protected function lib_hue($color) {
+		$hsl = $this->toHSL($this->assertColor($color));
 		return round($hsl[1]);
 	}
 
-	function lib_saturation($color) {
-		if ($color[0] != 'color') return 0;
-		$hsl = $this->toHSL($color);
+	protected function lib_saturation($color) {
+		$hsl = $this->toHSL($this->assertColor($color));
 		return round($hsl[2]);
 	}
 
-	function lib_lightness($color) {
-		if ($color[0] != 'color') return 0;
-		$hsl = $this->toHSL($color);
+	protected function lib_lightness($color) {
+		$hsl = $this->toHSL($this->assertColor($color));
 		return round($hsl[3]);
 	}
 
 	// get the alpha of a color
 	// defaults to 1 for non-colors or colors without an alpha
-	function lib_alpha($color) {
-		if ($color[0] != 'color') return 1;
-		return isset($color[4]) ? $color[4] : 1;
+	protected function lib_alpha($value) {
+		if (!is_null($color = $this->coerceColor($value))) {
+			return isset($color[4]) ? $color[4] : 1;
+		}
 	}
 
 	// set the alpha of the color
-	function lib_fade($args) {
+	protected function lib_fade($args) {
 		list($color, $alpha) = $this->colorArgs($args);
 		$color[4] = $this->clamp($alpha / 100.0);
 		return $color;
 	}
 
-	function lib_percentage($number) {
-		return array('%', $number[1]*100);
+	protected function lib_percentage($arg) {
+		$num = $this->assertNumber($arg);
+		return array("number", $num*100, "%");
 	}
 
 	// mixes two colors by weight
 	// mix(@color1, @color2, @weight);
 	// http://sass-lang.com/docs/yardoc/Sass/Script/Functions.html#mix-instance_method
-	function lib_mix($args) {
+	protected function lib_mix($args) {
 		if ($args[0] != "list" || count($args[2]) < 3)
 			$this->throwError("mix expects (color1, color2, weight)");
 
@@ -1754,13 +1028,18 @@ class lessc {
 		return $this->fixColor($new);
 	}
 
-	function assertColor($value, $error = "expected color value") {
+	protected function assertColor($value, $error = "expected color value") {
 		$color = $this->coerceColor($value);
 		if (is_null($color)) $this->throwError($error);
 		return $color;
 	}
 
-	function toHSL($color) {
+	protected function assertNumber($value, $error = "expecting number") {
+		if ($value[0] == "number") return $value[1];
+		$this->throwError($error);
+	}
+
+	protected function toHSL($color) {
 		if ($color[0] == 'hsl') return $color;
 
 		$r = $color[1] / 255;
@@ -1795,7 +1074,7 @@ class lessc {
 		return $out;
 	}
 
-	function toRGB_helper($comp, $temp1, $temp2) {
+	protected function toRGB_helper($comp, $temp1, $temp2) {
 		if ($comp < 0) $comp += 1.0;
 		elseif ($comp > 1) $comp -= 1.0;
 
@@ -1810,7 +1089,7 @@ class lessc {
 	 * Converts a hsl array into a color value in rgb.
 	 * Expects H to be in range of 0 to 360, S and L in 0 to 100
 	 */
-	function toRGB($color) {
+	protected function toRGB($color) {
 		if ($color == 'color') return $color;
 
 		$H = $color[1] / 360;
@@ -1837,7 +1116,7 @@ class lessc {
 		return $out;
 	}
 
-	function clamp($v, $max = 1, $min = 0) {
+	protected function clamp($v, $max = 1, $min = 0) {
 		return min($max, max($min, $v));
 	}
 
@@ -1845,7 +1124,7 @@ class lessc {
 	 * Convert the rgb, rgba, hsl color literals of function type
 	 * as returned by the parser into values of color type.
 	 */
-	function funcToColor($func) {
+	protected function funcToColor($func) {
 		$fname = $func[1];
 		if ($func[2][0] != 'list') return false; // need a list of arguments
 		$rawComponents = $func[2][2];
@@ -1858,7 +1137,7 @@ class lessc {
 				$val = isset($val[1]) ? floatval($val[1]) : 0;
 
 				if ($i == 0) $clamp = 360;
-				elseif ($i < 4) $clamp = 100;
+				elseif ($i < 3) $clamp = 100;
 				else $clamp = 1;
 
 				$hsl[] = $this->clamp($val, $clamp);
@@ -1874,11 +1153,17 @@ class lessc {
 			foreach	($rawComponents as $c) {
 				$c = $this->reduce($c);
 				if ($i < 4) {
-					if ($c[0] == '%') $components[] = 255 * ($c[1] / 100);
-					else $components[] = floatval($c[1]);
+					if ($c[0] == "number" && $c[2] == "%") {
+						$components[] = 255 * ($c[1] / 100);
+					} else {
+						$components[] = floatval($c[1]);
+					}
 				} elseif ($i == 4) {
-					if ($c[0] == '%') $components[] = 1.0 * ($c[1] / 100);
-					else $components[] = floatval($c[1]);
+					if ($c[0] == "number" && $c[2] == "%") {
+						$components[] = 1.0 * ($c[1] / 100);
+					} else {
+						$components[] = floatval($c[1]);
+					}
 				} else break;
 
 				$i++;
@@ -1891,22 +1176,14 @@ class lessc {
 		return false;
 	}
 
-	function toName($val) {
-		switch($val[0]) {
-		case "string":
-			return substr($val[1], 1, -1);
-		default:
-			return $val[1];
-		}
-	}
-
-	// reduce a delayed type to its final value
-	// dereference variables and solve equations
-	function reduce($var) {
-		// this is done here for infinite loop checking
-		if ($var[0] == "variable") {
-			$key = is_array($var[1]) ?
-				$this->vPrefix.$this->toName($this->reduce($var[1])) : $var[1];
+	protected function reduce($value, $forExpression = false) {
+		switch ($value[0]) {
+		case "variable":
+			$key = $value[1];
+			if (is_array($key)) {
+				$key = $this->reduce($key);
+				$key = $this->vPrefix . $this->compileValue($this->lib_e($key));
+			}
 
 			$seen =& $this->env->seenNames;
 
@@ -1915,62 +1192,109 @@ class lessc {
 			}
 
 			$seen[$key] = true;
-
-			$out = $this->reduce($this->get($key));
-
+			$out = $this->reduce($this->get($key, self::$defaultValue));
 			$seen[$key] = false;
-
 			return $out;
+		case "list":
+			foreach ($value[2] as &$item) {
+				$item = $this->reduce($item, $forExpression);
+			}
+			return $value;
+		case "expression":
+			return $this->evaluate($value);
+		case "string":
+			foreach ($value[2] as &$part) {
+				if (is_array($part)) {
+					$strip = $part[0] == "variable";
+					$part = $this->reduce($part);
+					if ($strip) $part = $this->lib_e($part);
+				}
+			}
+			return $value;
+		case "escape":
+			list(,$inner) = $value;
+			return $this->lib_e($this->reduce($inner));
+		case "function":
+			$color = $this->funcToColor($value);
+			if ($color) return $color;
+
+			list(, $name, $args) = $value;
+			if ($name == "%") $name = "_sprintf";
+			$f = isset($this->libFunctions[$name]) ?
+				$this->libFunctions[$name] : array($this, 'lib_'.$name);
+
+			if (is_callable($f)) {
+				if ($args[0] == 'list')
+					$args = self::compressList($args[2], $args[1]);
+
+				$ret = call_user_func($f, $this->reduce($args, true), $this);
+
+				if (is_null($ret)) {
+					return array("string", "", array(
+						$name, "(", $args, ")"
+					));
+				}
+
+				// convert to a typed value if the result is a php primitive
+				if (is_numeric($ret)) $ret = array('number', $ret, "");
+				elseif (!is_array($ret)) $ret = array('keyword', $ret);
+
+				return $ret;
+			}
+
+			// plain function, reduce args
+			$value[2] = $this->reduce($value[2]);
+			return $value;
+		case "unary":
+			list(, $op, $exp) = $value;
+			$exp = $this->reduce($exp);
+
+			if ($exp[0] == "number") {
+				switch ($op) {
+				case "+":
+					return $exp;
+				case "-":
+					$exp[1] *= -1;
+					return $exp;
+				}
+			}
+			return array("string", "", array($op, $exp));
 		}
 
-		while (in_array($var[0], self::$dtypes)) {
-			if ($var[0] == 'list') {
-				foreach ($var[2] as &$value) $value = $this->reduce($value);
+		if ($forExpression) {
+			switch ($value[0]) {
+			case "keyword":
+				if ($color = $this->coerceColor($value)) {
+					return $color;
+				}
 				break;
-			} elseif ($var[0] == 'expression') {
-				$var = $this->evaluate($var[1], $var[2], $var[3]);
-			} elseif ($var[0] == 'lookup') {
-				// do accessor here....
-				$var = array('number', 0);
-			} elseif ($var[0] == 'function') {
-				$color = $this->funcToColor($var);
-				if ($color) $var = $color;
-				else {
-					list($_, $name, $args) = $var;
-					if ($name == "%") $name = "_sprintf";
-					$f = isset($this->libFunctions[$name]) ?
-						$this->libFunctions[$name] : array($this, 'lib_'.$name);
-
-					if (is_callable($f)) {
-						if ($args[0] == 'list')
-							$args = $this->compressList($args[2], $args[1]);
-
-						$var = call_user_func($f, $this->reduce($args), $this);
-
-						// convert to a typed value if the result is a php primitive
-						if (is_numeric($var)) $var = array('number', $var);
-						elseif (!is_array($var)) $var = array('keyword', $var);
-					} else {
-						// plain function, reduce args
-						$var[2] = $this->reduce($var[2]);
-					}
-				}
-				break; // done reducing after a function
-			} elseif ($var[0] == 'negative') {
-				$value = $this->reduce($var[1]);
-				if (is_numeric($value[1])) {
-					$value[1] = -1*$value[1];
-				}
-				$var = $value;
+			case "raw_color":
+				return $this->coerceColor($value);
 			}
 		}
 
-		return $var;
+		return $value;
 	}
 
-	function coerceColor($value) {
+
+	// coerce a value for use in color operation
+	protected function coerceColor($value) {
 		switch($value[0]) {
 			case 'color': return $value;
+			case 'raw_color':
+				$c = array("color", 0, 0, 0);
+				$colorStr = substr($value[1], 1);
+				$num = hexdec($colorStr);
+				$width = strlen($colorStr) == 3 ? 16 : 256;
+
+				for ($i = 3; $i > 0; $i--) { // 3 2 1
+					$t = $num % $width;
+					$num /= $width;
+
+					$c[$i] = $t * (256/$width) + $t * floor(16/$width);
+				}
+
+				return $c;
 			case 'keyword':
 				$name = $value[1];
 				if (isset(self::$cssColors[$name])) {
@@ -1981,24 +1305,49 @@ class lessc {
 		}
 	}
 
-	function toBool($a) {
+	// make something string like into a string
+	protected function coerceString($value) {
+		switch ($value[0]) {
+		case "string":
+			return $value;
+		case "keyword":
+			return array("string", "", array($value[1]));
+		}
+		return null;
+	}
+
+	// turn list of length 1 into value type
+	protected function flattenList($value) {
+		if ($value[0] == "list" && count($value[2]) == 1) {
+			return $this->flattenList($value[2][0]);
+		}
+		return $value;
+	}
+
+	protected function toBool($a) {
 		if ($a) return self::$TRUE;
 		else return self::$FALSE;
 	}
 
 	// evaluate an expression
-	function evaluate($op, $left, $right) {
-		$left = $this->reduce($left);
-		$right = $this->reduce($right);
+	protected function evaluate($exp) {
+		list(, $op, $left, $right, $whiteBefore, $whiteAfter) = $exp;
 
-		if ($left_color = $this->coerceColor($left)) {
-			$left = $left_color;
+		$left = $this->reduce($left, true);
+		$right = $this->reduce($right, true);
+
+		if ($leftColor = $this->coerceColor($left)) {
+			$left = $leftColor;
 		}
 
-		if ($right_color = $this->coerceColor($right)) {
-			$right = $right_color;
+		if ($rightColor = $this->coerceColor($right)) {
+			$right = $rightColor;
 		}
 
+		$ltype = $left[0];
+		$rtype = $right[0];
+
+		// operators that work on all types
 		if ($op == "and") {
 			return $this->toBool($left == self::$TRUE && $right == self::$TRUE);
 		}
@@ -2007,45 +1356,43 @@ class lessc {
 			return $this->toBool($this->eq($left, $right) );
 		}
 
-		if ($left[0] == 'color' && $right[0] == 'color') {
-			$out = $this->op_color_color($op, $left, $right);
-			return $out;
+		if ($op == "+" && !is_null($str = $this->stringConcatenate($left, $right))) {
+			return $str;
 		}
 
-		if ($left[0] == 'color') {
-			return $this->op_color_number($op, $left, $right);
+		// type based operators
+		$fname = "op_${ltype}_${rtype}";
+		if (is_callable(array($this, $fname))) {
+			$out = $this->$fname($op, $left, $right);
+			if (!is_null($out)) return $out;
 		}
 
-		if ($right[0] == 'color') {
-			return $this->op_number_color($op, $left, $right);
-		}
+		// make the expression look it did before being parsed
+		$paddedOp = $op;
+		if ($whiteBefore) $paddedOp = " " . $paddedOp;
+		if ($whiteAfter) $paddedOp .= " ";
 
-		// concatenate strings
-		if ($op == '+' && $left[0] == 'string') {
-			$append = $this->compileValue($right);
-			if ($this->quoted($append)) $append = substr($append, 1, -1);
-
-			$lhs = $this->compileValue($left);
-			if ($q = $this->quoted($lhs)) $lhs = substr($lhs, 1, -1);
-			if (!$q) $q = '';
-
-			return array('string', $q.$lhs.$append.$q);
-		}
-
-		if ($left[0] == 'keyword' || $right[0] == 'keyword' ||
-			$left[0] == 'string' || $right[0] == 'string')
-		{
-			// look for negative op
-			if ($op == '-') $right[1] = '-'.$right[1];
-			return array('keyword', $this->compileValue($left) .' '. $this->compileValue($right));
-		}
-
-		// default to number operation
-		return $this->op_number_number($op, $left, $right);
+		return array("string", "", array($left, $paddedOp, $right));
 	}
 
+	protected function stringConcatenate($left, $right) {
+		if ($strLeft = $this->coerceString($left)) {
+			if ($right[0] == "string") {
+				$right[1] = "";
+			}
+			$strLeft[2][] = $right;
+			return $strLeft;
+		}
+
+		if ($strRight = $this->coerceString($right)) {
+			array_unshift($strRight[2], $left);
+			return $strRight;
+		}
+	}
+
+
 	// make sure a color's components don't go out of bounds
-	function fixColor($c) {
+	protected function fixColor($c) {
 		foreach (range(1, 3) as $i) {
 			if ($c[$i] < 0) $c[$i] = 0;
 			if ($c[$i] > 255) $c[$i] = 255;
@@ -2054,20 +1401,20 @@ class lessc {
 		return $c;
 	}
 
-	function op_number_color($op, $lft, $rgt) {
-		if ($op == '+' || $op = '*') {
+	protected function op_number_color($op, $lft, $rgt) {
+		if ($op == '+' || $op == '*') {
 			return $this->op_color_number($op, $rgt, $lft);
 		}
 	}
 
-	function op_color_number($op, $lft, $rgt) {
+	protected function op_color_number($op, $lft, $rgt) {
 		if ($rgt[0] == '%') $rgt[1] /= 100;
 
 		return $this->op_color_color($op, $lft,
 			array_fill(1, count($lft) - 1, $rgt[1]));
 	}
 
-	function op_color_color($op, $left, $right) {
+	protected function op_color_color($op, $left, $right) {
 		$out = array('color');
 		$max = count($left) > count($right) ? count($left) : count($right);
 		foreach (range(1, $max - 1) as $i) {
@@ -2098,9 +1445,8 @@ class lessc {
 	}
 
 	// operator on two numbers
-	function op_number_number($op, $left, $right) {
-		$type = is_null($left) ? "number" : $left[0];
-		if ($type == "number") $type = $right[0];
+	protected function op_number_number($op, $left, $right) {
+		$unit = empty($left[2]) ? $right[2] : $left[2];
 
 		$value = 0;
 		switch ($op) {
@@ -2132,344 +1478,152 @@ class lessc {
 			$this->throwError('parse error: unknown number operator: '.$op);
 		}
 
-		return array($type, $value);
+		return array("number", $value, $unit);
 	}
 
 
 	/* environment functions */
 
-	// push a new block on the stack, used for parsing
-	function pushBlock($tags) {
+	protected function makeOutputBlock($type, $selectors = null) {
 		$b = new stdclass;
-		$b->parent = $this->env;
-
-		$b->id = self::$nextBlockId++;
-		$b->is_vararg = false;
-		$b->tags = $tags;
-		$b->props = array();
+		$b->lines = array();
 		$b->children = array();
-
-		$this->env = $b;
+		$b->selectors = $selectors;
+		$b->type = $type;
+		$b->parent = $this->scope;
 		return $b;
 	}
 
-	// push a block that doesn't multiply tags
-	function pushSpecialBlock($name) {
-		$b = $this->pushBlock(array($name));
-		$b->no_multiply = true;
-		return $b;
-	}
-
-	// used for compiliation variable state
-	function pushEnv() {
+	// the state of execution
+	protected function pushEnv($block = null) {
 		$e = new stdclass;
 		$e->parent = $this->env;
-
-		$this->store = array();
+		$e->store = array();
+		$e->block = $block;
 
 		$this->env = $e;
 		return $e;
 	}
 
 	// pop something off the stack
-	function pop() {
+	protected function popEnv() {
 		$old = $this->env;
 		$this->env = $this->env->parent;
 		return $old;
 	}
 
 	// set something in the current env
-	function set($name, $value) {
+	protected function set($name, $value) {
 		$this->env->store[$name] = $value;
 	}
 
-	// append an property
-	function append($prop, $pos = null) {
-		if (!is_null($pos)) $prop[-1] = $pos;
-		$this->env->props[] = $prop;
-	}
 
 	// get the highest occurrence entry for a name
-	function get($name) {
+	protected function get($name, $default=null) {
 		$current = $this->env;
 
-		$is_arguments = $name == $this->vPrefix . 'arguments';
+		$isArguments = $name == $this->vPrefix . 'arguments';
 		while ($current) {
-			if ($is_arguments && isset($current->arguments)) {
+			if ($isArguments && isset($current->arguments)) {
 				return array('list', ' ', $current->arguments);
 			}
 
 			if (isset($current->store[$name]))
 				return $current->store[$name];
-			else
-				$current = $current->parent;
-		}
-
-		return null;
-	}
-
-	/* raw parsing functions */
-
-	function literal($what, $eatWhitespace = true) {
-		// this is here mainly prevent notice from { } string accessor
-		if ($this->count >= strlen($this->buffer)) return false;
-
-		// shortcut on single letter
-		if (!$eatWhitespace && strlen($what) == 1) {
-			if ($this->buffer{$this->count} == $what) {
-				$this->count++;
-				return true;
+			else {
+				$current = isset($current->storeParent) ?
+					$current->storeParent : $current->parent;
 			}
-			else return false;
 		}
 
-		return $this->match($this->preg_quote($what), $m, $eatWhitespace);
-	}
-
-	function preg_quote($what) {
-		return preg_quote($what, '/');
-	}
-
-	// advance counter to next occurrence of $what
-	// $until - don't include $what in advance
-	// $allowNewline, if string, will be used as valid char set
-	function to($what, &$out, $until = false, $allowNewline = false) {
-		if (is_string($allowNewline)) {
-			$validChars = $allowNewline;
-		} else {
-			$validChars = $allowNewline ? "." : "[^\n]";
-		}
-		if (!$this->match('('.$validChars.'*?)'.$this->preg_quote($what), $m, !$until)) return false;
-		if ($until) $this->count -= strlen($what); // give back $what
-		$out = $m[1];
-		return true;
-	}
-
-	// try to match something on head of buffer
-	function match($regex, &$out, $eatWhitespace = true) {
-		$r = '/'.$regex.($eatWhitespace ? '\s*' : '').'/Ais';
-		if (preg_match($r, $this->buffer, $out, null, $this->count)) {
-			$this->count += strlen($out[0]);
-			return true;
-		}
-		return false;
-	}
-
-	// match something without consuming it
-	function peek($regex, &$out = null) {
-		$r = '/'.$regex.'/Ais';
-		$result = preg_match($r, $this->buffer, $out, null, $this->count);
-
-		return $result;
-	}
-
-	// seek to a spot in the buffer or return where we are on no argument
-	function seek($where = null) {
-		if ($where === null) return $this->count;
-		else $this->count = $where;
-		return true;
-	}
-
-	/**
-	 * Initialize state for a fresh parse
-	 */
-	protected function prepareParser($buff) {
-		$this->env = null;
-		$this->expandStack = array();
-		$this->indentLevel = 0;
-		$this->count = 0;
-		$this->line = 1;
-
-		$this->buffer = $this->removeComments($buff);
-		$this->pushBlock(null); // set up global scope
-
-		// trim whitespace on head
-		if (preg_match('/^\s+/', $this->buffer, $m)) {
-			$this->line  += substr_count($m[0], "\n");
-			$this->buffer = ltrim($this->buffer);
-		}
-	}
-
-	// create a child parser (for compiling an import)
-	protected function createChild($fname) {
-		$less = new lessc($fname);
-		$less->importDir = array_merge((array)$less->importDir, (array)$this->importDir);
-		$less->indentChar = $this->indentChar;
-		$less->compat = $this->compat;
-		return $less;
-	}
-
-	// parse code and return intermediate tree
-	public function parseTree($str = null) {
-		$this->prepareParser(is_null($str) ? $this->buffer : $str);
-		while (false !== $this->parseChunk());
-
-		if ($this->count != strlen($this->buffer))
-			$this->throwError();
-
-		if (!is_null($this->env->parent))
-			throw new exception('parse error: unclosed block');
-
-		$root = $this->env;
-		$this->env = null;
-		return $root;
+		return $default;
 	}
 
 	// inject array of unparsed strings into environment as variables
 	protected function injectVariables($args) {
 		$this->pushEnv();
-		$parser = new lessc();
-		foreach ($args as $name => $str_value) {
+		$parser = new lessc_parser($this, __METHOD__);
+		foreach ($args as $name => $strValue) {
 			if ($name{0} != '@') $name = '@'.$name;
 			$parser->count = 0;
-			$parser->buffer = (string)$str_value;
+			$parser->buffer = (string)$strValue;
 			if (!$parser->propertyValue($value)) {
-				throw new Exception("failed to parse passed in variable $name: $str_value");
+				throw new Exception("failed to parse passed in variable $name: $strValue");
 			}
 
 			$this->set($name, $value);
 		}
 	}
 
-	// parse and compile buffer
-	function parse($str = null, $initial_variables = null) {
+	/**
+	 * Initialize any static state, can initialize parser for a file
+	 * $opts isn't used yet
+	 */
+	public function __construct($fname = null) {
+		if ($fname !== null) {
+			// used for deprecated parse method
+			$this->_parseFile = $fname;
+		}
+	}
+
+	public function compile($string, $name = null) {
 		$locale = setlocale(LC_NUMERIC, 0);
 		setlocale(LC_NUMERIC, "C");
-		$root = $this->parseTree($str);
 
-		if ($initial_variables) $this->injectVariables($initial_variables);
-		$out = $this->compileBlock($root);
+		$this->parser = $this->makeParser($name);
+		$root = $this->parser->parse($string);
+
+		$this->env = null;
+		$this->scope = null;
+
+		$this->formatter = $this->newFormatter();
+
+		if (!empty($this->registeredVars)) {
+			$this->injectVariables($this->registeredVars);
+		}
+
+		$this->sourceParser = $this->parser; // used for error messages
+		$this->compileBlock($root);
+
+		ob_start();
+		$this->formatter->block($this->scope);
+		$out = ob_get_clean();
 		setlocale(LC_NUMERIC, $locale);
 		return $out;
 	}
 
-	/**
-	 * Uses the current value of $this->count to show line and line number
-	 */
-	function throwError($msg = 'parse error') {
-		if (!empty($this->sourceParser)) {
-			$this->sourceParser->count = $this->count;
-			return $this->sourceParser->throwError($msg);
-		} elseif ($this->count > 0) {
-			$line = $this->line + substr_count(substr($this->buffer, 0, $this->count), "\n");
-			if (isset($this->fileName)) {
-				$loc = $this->fileName.' on line '.$line;
-			} else {
-				$loc = "line: ".$line;
-			}
-
-			if ($this->peek("(.*?)(\n|$)", $m))
-				throw new exception($msg.': failed at `'.$m[1].'` '.$loc);
+	public function compileFile($fname, $outFname = null) {
+		if (!is_readable($fname)) {
+			throw new Exception('load error: failed to find '.$fname);
 		}
 
-		throw new exception($msg);
-	}
+		$pi = pathinfo($fname);
 
-	/**
-	 * Initialize any static state, can initialize parser for a file
-	 */
-	function __construct($fname = null, $opts = null) {
-		if (!self::$operatorString) {
-			self::$operatorString =
-				'('.implode('|', array_map(array($this, 'preg_quote'),
-					array_keys(self::$precedence))).')';
+		$oldImport = $this->importDir;
+
+		$this->importDir = (array)$this->importDir;
+		$this->importDir[] = $pi['dirname'].'/';
+
+		$this->allParsedFiles = array();
+		$this->addParsedFile($fname);
+
+		$out = $this->compile(file_get_contents($fname), $fname);
+
+		$this->importDir = $oldImport;
+
+		if ($outFname !== null) {
+			return file_put_contents($outFname, $out);
 		}
 
-		if ($fname) {
-			if (!is_file($fname)) {
-				throw new Exception('load error: failed to find '.$fname);
-			}
-			$pi = pathinfo($fname);
-
-			$this->fileName = $fname;
-			$this->importDir = $pi['dirname'].'/';
-			$this->buffer = file_get_contents($fname);
-
-			$this->addParsedFile($fname);
-		}
+		return $out;
 	}
 
-	public function registerFunction($name, $func) {
-		$this->libFunctions[$name] = $func;
-	}
-
-	public function unregisterFunction($name) {
-		unset($this->libFunctions[$name]);
-	}
-
-	// remove comments from $text
-	// todo: make it work for all functions, not just url
-	function removeComments($text) {
-		$look = array(
-			'url(', '//', '/*', '"', "'"
-		);
-
-		$out = '';
-		$min = null;
-		$done = false;
-		while (true) {
-			// find the next item
-			foreach ($look as $token) {
-				$pos = strpos($text, $token);
-				if ($pos !== false) {
-					if (!isset($min) || $pos < $min[1]) $min = array($token, $pos);
-				}
-			}
-
-			if (is_null($min)) break;
-
-			$count = $min[1];
-			$skip = 0;
-			$newlines = 0;
-			switch ($min[0]) {
-			case 'url(':
-				if (preg_match('/url\(.*?\)/', $text, $m, 0, $count))
-					$count += strlen($m[0]) - strlen($min[0]);
-				break;
-			case '"':
-			case "'":
-				if (preg_match('/'.$min[0].'.*?'.$min[0].'/', $text, $m, 0, $count))
-					$count += strlen($m[0]) - 1;
-				break;
-			case '//':
-				$skip = strpos($text, "\n", $count);
-				if ($skip === false) $skip = strlen($text) - $count;
-				else $skip -= $count;
-				break;
-			case '/*':
-				if (preg_match('/\/\*.*?\*\//s', $text, $m, 0, $count)) {
-					$skip = strlen($m[0]);
-					$newlines = substr_count($m[0], "\n");
-				}
-				break;
-			}
-
-			if ($skip == 0) $count += strlen($min[0]);
-
-			$out .= substr($text, 0, $count).str_repeat("\n", $newlines);
-			$text = substr($text, $count + $skip);
-
-			$min = null;
-		}
-
-		return $out.$text;
-	}
-
-	public function allParsedFiles() { return $this->allParsedFiles; }
-	protected function addParsedFile($file) {
-		$this->allParsedFiles[realpath($file)] = filemtime($file);
-	}
-
-
-	// compile file $in to file $out if $in is newer than $out
-	// returns true when it compiles, false otherwise
-	public static function ccompile($in, $out) {
+	// compile only if changed input has changed or output doesn't exist
+	public function checkedCompile($in, $out) {
 		if (!is_file($out) || filemtime($in) > filemtime($out)) {
-			$less = new lessc($in);
-			file_put_contents($out, $less->parse());
+			$this->compileFile($in, $out);
 			return true;
 		}
-
 		return false;
 	}
 
@@ -2493,8 +1647,7 @@ class lessc {
 	 * @param bool $force Force rebuild?
 	 * @return array lessphp cache structure
 	 */
-	public static function cexecute($in, $force = false) {
-
+	public function cachedCompile($in, $force = false) {
 		// assume no root
 		$root = null;
 
@@ -2524,11 +1677,10 @@ class lessc {
 
 		if ($root !== null) {
 			// If we have a root value which means we should rebuild.
-			$less = new lessc($root);
 			$out = array();
 			$out['root'] = $root;
-			$out['compiled'] = $less->parse();
-			$out['files'] = $less->allParsedFiles();
+			$out['compiled'] = $this->compileFile($root);
+			$out['files'] = $this->allParsedFiles();
 			$out['updated'] = time();
 			return $out;
 		} else {
@@ -2539,6 +1691,118 @@ class lessc {
 
 	}
 
+	// parse and compile buffer
+	// This is deprecated
+	public function parse($str = null, $initialVariables = null) {
+		if (is_array($str)) {
+			$initialVariables = $str;
+			$str = null;
+		}
+
+		$oldVars = $this->registeredVars;
+		if ($initialVariables !== null) {
+			$this->setVariables($initialVariables);
+		}
+
+		if ($str == null) {
+			if (empty($this->_parseFile)) {
+				throw new exception("nothing to parse");
+			}
+
+			$out = $this->compileFile($this->_parseFile);
+		} else {
+			$out = $this->compile($str);
+		}
+
+		$this->registeredVars = $oldVars;
+		return $out;
+	}
+
+	protected function makeParser($name) {
+		$parser = new lessc_parser($this, $name);
+		$parser->writeComments = $this->preserveComments;
+
+		return $parser;
+	}
+
+	public function setFormatter($name) {
+		$this->formatterName = $name;
+	}
+
+	protected function newFormatter() {
+		$className = "lessc_formatter_lessjs";
+		if (!empty($this->formatterName)) {
+			if (!is_string($this->formatterName))
+				return $this->formatterName;
+			$className = "lessc_formatter_$this->formatterName";
+		}
+
+		return new $className;
+	}
+
+	public function setPreserveComments($preserve) {
+		$this->preserveComments = $preserve;
+	}
+
+	public function registerFunction($name, $func) {
+		$this->libFunctions[$name] = $func;
+	}
+
+	public function unregisterFunction($name) {
+		unset($this->libFunctions[$name]);
+	}
+
+	public function setVariables($variables) {
+		$this->registeredVars = array_merge($this->registeredVars, $variables);
+	}
+
+	public function unsetVariable($name) {
+		unset($this->registeredVars[$name]);
+	}
+
+	public function setImportDir($dirs) {
+		$this->importDir = (array)$dirs;
+	}
+
+	public function addImportDir($dir) {
+		$this->importDir = (array)$this->importDir;
+		$this->importDir[] = $dir;
+	}
+
+	public function allParsedFiles() {
+		return $this->allParsedFiles;
+	}
+
+	protected function addParsedFile($file) {
+		$this->allParsedFiles[realpath($file)] = filemtime($file);
+	}
+
+	/**
+	 * Uses the current value of $this->count to show line and line number
+	 */
+	protected function throwError($msg = null) {
+		if ($this->sourceLoc >= 0) {
+			$this->sourceParser->throwError($msg, $this->sourceLoc);
+		}
+		throw new exception($msg);
+	}
+
+	// compile file $in to file $out if $in is newer than $out
+	// returns true when it compiles, false otherwise
+	public static function ccompile($in, $out, $less = null) {
+		if ($less === null) {
+			$less = new self;
+		}
+		return $less->checkedCompile($in, $out);
+	}
+
+	public static function cexecute($in, $force = false, $less = null) {
+		if ($less === null) {
+			$less = new self;
+		}
+		return $less->cachedCompile($in, $force);
+	}
+
 	static protected $cssColors = array(
 		'aliceblue' => '240,248,255',
 		'antiquewhite' => '250,235,215',
@@ -2690,3 +1954,1403 @@ class lessc {
 	);
 }
 
+// responsible for taking a string of LESS code and converting it into a
+// syntax tree
+class lessc_parser {
+	static protected $nextBlockId = 0; // used to uniquely identify blocks
+
+	static protected $precedence = array(
+		'=<' => 0,
+		'>=' => 0,
+		'=' => 0,
+		'<' => 0,
+		'>' => 0,
+
+		'+' => 1,
+		'-' => 1,
+		'*' => 2,
+		'/' => 2,
+		'%' => 2,
+	);
+
+	static protected $whitePattern;
+	static protected $commentMulti;
+
+	static protected $commentSingle = "//";
+	static protected $commentMultiLeft = "/*";
+	static protected $commentMultiRight = "*/";
+
+	// regex string to match any of the operators
+	static protected $operatorString;
+
+	// these properties will supress division unless it's inside parenthases
+	static protected $supressDivisionProps =
+		array('/border-radius$/i', '/^font$/i');
+
+	protected $blockDirectives = array("font-face", "keyframes", "page", "-moz-document");
+	protected $lineDirectives = array("charset");
+
+	/**
+	 * if we are in parens we can be more liberal with whitespace around
+	 * operators because it must evaluate to a single value and thus is less
+	 * ambiguous.
+	 *
+	 * Consider:
+	 *     property1: 10 -5; // is two numbers, 10 and -5
+	 *     property2: (10 -5); // should evaluate to 5
+	 */
+	protected $inParens = false;
+
+	// caches preg escaped literals
+	static protected $literalCache = array();
+
+	public function __construct($lessc, $sourceName = null) {
+		$this->eatWhiteDefault = true;
+		// reference to less needed for vPrefix, mPrefix, and parentSelector
+		$this->lessc = $lessc;
+
+		$this->sourceName = $sourceName; // name used for error messages
+
+		$this->writeComments = false;
+
+		if (!self::$operatorString) {
+			self::$operatorString =
+				'('.implode('|', array_map(array('lessc', 'preg_quote'),
+					array_keys(self::$precedence))).')';
+
+			$commentSingle = lessc::preg_quote(self::$commentSingle);
+			$commentMultiLeft = lessc::preg_quote(self::$commentMultiLeft);
+			$commentMultiRight = lessc::preg_quote(self::$commentMultiRight);
+
+			self::$commentMulti = $commentMultiLeft.'.*?'.$commentMultiRight;
+			self::$whitePattern = '/'.$commentSingle.'[^\n]*\s*|('.self::$commentMulti.')\s*|\s+/Ais';
+		}
+	}
+
+	public function parse($buffer) {
+		$this->count = 0;
+		$this->line = 1;
+
+		$this->env = null; // block stack
+		$this->buffer = $this->writeComments ? $buffer : $this->removeComments($buffer);
+		$this->pushSpecialBlock("root");
+		$this->eatWhiteDefault = true;
+		$this->seenComments = array();
+
+		// trim whitespace on head
+		// if (preg_match('/^\s+/', $this->buffer, $m)) {
+		// 	$this->line += substr_count($m[0], "\n");
+		// 	$this->buffer = ltrim($this->buffer);
+		// }
+		$this->whitespace();
+
+		// parse the entire file
+		$lastCount = $this->count;
+		while (false !== $this->parseChunk());
+
+		if ($this->count != strlen($this->buffer))
+			$this->throwError();
+
+		// TODO report where the block was opened
+		if (!is_null($this->env->parent))
+			throw new exception('parse error: unclosed block');
+
+		return $this->env;
+	}
+
+	/**
+	 * Parse a single chunk off the head of the buffer and append it to the
+	 * current parse environment.
+	 * Returns false when the buffer is empty, or when there is an error.
+	 *
+	 * This function is called repeatedly until the entire document is
+	 * parsed.
+	 *
+	 * This parser is most similar to a recursive descent parser. Single
+	 * functions represent discrete grammatical rules for the language, and
+	 * they are able to capture the text that represents those rules.
+	 *
+	 * Consider the function lessc::keyword(). (all parse functions are
+	 * structured the same)
+	 *
+	 * The function takes a single reference argument. When calling the
+	 * function it will attempt to match a keyword on the head of the buffer.
+	 * If it is successful, it will place the keyword in the referenced
+	 * argument, advance the position in the buffer, and return true. If it
+	 * fails then it won't advance the buffer and it will return false.
+	 *
+	 * All of these parse functions are powered by lessc::match(), which behaves
+	 * the same way, but takes a literal regular expression. Sometimes it is
+	 * more convenient to use match instead of creating a new function.
+	 *
+	 * Because of the format of the functions, to parse an entire string of
+	 * grammatical rules, you can chain them together using &&.
+	 *
+	 * But, if some of the rules in the chain succeed before one fails, then
+	 * the buffer position will be left at an invalid state. In order to
+	 * avoid this, lessc::seek() is used to remember and set buffer positions.
+	 *
+	 * Before parsing a chain, use $s = $this->seek() to remember the current
+	 * position into $s. Then if a chain fails, use $this->seek($s) to
+	 * go back where we started.
+	 */
+	protected function parseChunk() {
+		if (empty($this->buffer)) return false;
+		$s = $this->seek();
+
+		// setting a property
+		if ($this->keyword($key) && $this->assign() &&
+			$this->propertyValue($value, $key) && $this->end())
+		{
+			$this->append(array('assign', $key, $value), $s);
+			return true;
+		} else {
+			$this->seek($s);
+		}
+
+
+		// look for special css blocks
+		if ($this->literal('@', false)) {
+			$this->count--;
+
+			// media
+			if ($this->literal('@media')) {
+				if (($this->mediaQueryList($mediaQueries) || true)
+					&& $this->literal('{'))
+				{
+					$media = $this->pushSpecialBlock("media");
+					$media->queries = is_null($mediaQueries) ? array() : $mediaQueries;
+					return true;
+				} else {
+					$this->seek($s);
+					return false;
+				}
+			}
+
+			if ($this->literal("@", false) && $this->keyword($dirName)) {
+				if ($this->isDirective($dirName, $this->blockDirectives)) {
+					if (($this->openString("{", $dirValue, null, array(";")) || true) &&
+						$this->literal("{"))
+					{
+						$dir = $this->pushSpecialBlock("directive");
+						$dir->name = $dirName;
+						if (isset($dirValue)) $dir->value = $dirValue;
+						return true;
+					}
+				} elseif ($this->isDirective($dirName, $this->lineDirectives)) {
+					if ($this->propertyValue($dirValue) && $this->end()) {
+						$this->append(array("directive", $dirName, $dirValue));
+						return true;
+					}
+				}
+			}
+
+			$this->seek($s);
+		}
+
+		// setting a variable
+		if ($this->variable($var) && $this->assign() &&
+			$this->propertyValue($value) && $this->end())
+		{
+			$this->append(array('assign', $var, $value), $s);
+			return true;
+		} else {
+			$this->seek($s);
+		}
+
+		if ($this->import($importValue)) {
+			$this->append($importValue, $s);
+			return true;
+		}
+
+		// opening parametric mixin
+		if ($this->tag($tag, true) && $this->argumentDef($args, $isVararg) &&
+			($this->guards($guards) || true) &&
+			$this->literal('{'))
+		{
+			$block = $this->pushBlock($this->fixTags(array($tag)));
+			$block->args = $args;
+			$block->isVararg = $isVararg;
+			if (!empty($guards)) $block->guards = $guards;
+			return true;
+		} else {
+			$this->seek($s);
+		}
+
+		// opening a simple block
+		if ($this->tags($tags) && $this->literal('{')) {
+			$tags = $this->fixTags($tags);
+			$this->pushBlock($tags);
+			return true;
+		} else {
+			$this->seek($s);
+		}
+
+		// closing a block
+		if ($this->literal('}', false)) {
+			try {
+				$block = $this->pop();
+			} catch (exception $e) {
+				$this->seek($s);
+				$this->throwError($e->getMessage());
+			}
+
+			$hidden = false;
+			if (is_null($block->type)) {
+				$hidden = true;
+				if (!isset($block->args)) {
+					foreach ($block->tags as $tag) {
+						if (!is_string($tag) || $tag{0} != $this->lessc->mPrefix) {
+							$hidden = false;
+							break;
+						}
+					}
+				}
+
+				foreach ($block->tags as $tag) {
+					if (is_string($tag)) {
+						$this->env->children[$tag][] = $block;
+					}
+				}
+			}
+
+			if (!$hidden) {
+				$this->append(array('block', $block), $s);
+			}
+
+			// this is done here so comments aren't bundled into he block that
+			// was just closed
+			$this->whitespace();
+			return true;
+		}
+
+		// mixin
+		if ($this->mixinTags($tags) &&
+			($this->argumentValues($argv) || true) &&
+			($this->keyword($suffix) || true) && $this->end())
+		{
+			$tags = $this->fixTags($tags);
+			$this->append(array('mixin', $tags, $argv, $suffix), $s);
+			return true;
+		} else {
+			$this->seek($s);
+		}
+
+		// spare ;
+		if ($this->literal(';')) return true;
+
+		return false; // got nothing, throw error
+	}
+
+	protected function isDirective($dirname, $directives) {
+		// TODO: cache pattern in parser
+		$pattern = implode("|",
+			array_map(array("lessc", "preg_quote"), $directives));
+		$pattern = '/^(-[a-z-]+-)?(' . $pattern . ')$/i';
+
+		return preg_match($pattern, $dirname);
+	}
+
+	protected function fixTags($tags) {
+		// move @ tags out of variable namespace
+		foreach ($tags as &$tag) {
+			if ($tag{0} == $this->lessc->vPrefix)
+				$tag[0] = $this->lessc->mPrefix;
+		}
+		return $tags;
+	}
+
+	// a list of expressions
+	protected function expressionList(&$exps) {
+		$values = array();
+
+		while ($this->expression($exp)) {
+			$values[] = $exp;
+		}
+
+		if (count($values) == 0) return false;
+
+		$exps = lessc::compressList($values, ' ');
+		return true;
+	}
+
+	/**
+	 * Attempt to consume an expression.
+	 * @link http://en.wikipedia.org/wiki/Operator-precedence_parser#Pseudo-code
+	 */
+	protected function expression(&$out) {
+		if ($this->value($lhs)) {
+			$out = $this->expHelper($lhs, 0);
+
+			// look for / shorthand
+			if (!empty($this->env->supressedDivision)) {
+				unset($this->env->supressedDivision);
+				$s = $this->seek();
+				if ($this->literal("/") && $this->value($rhs)) {
+					$out = array("list", "",
+						array($out, array("keyword", "/"), $rhs));
+				} else {
+					$this->seek($s);
+				}
+			}
+
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * recursively parse infix equation with $lhs at precedence $minP
+	 */
+	protected function expHelper($lhs, $minP) {
+		$this->inExp = true;
+		$ss = $this->seek();
+
+		while (true) {
+			$whiteBefore = isset($this->buffer[$this->count - 1]) &&
+				ctype_space($this->buffer[$this->count - 1]);
+
+			// If there is whitespace before the operator, then we require
+			// whitespace after the operator for it to be an expression
+			$needWhite = $whiteBefore && !$this->inParens;
+
+			if ($this->match(self::$operatorString.($needWhite ? '\s' : ''), $m) && self::$precedence[$m[1]] >= $minP) {
+				if (!$this->inParens && isset($this->env->currentProperty) && $m[1] == "/" && empty($this->env->supressedDivision)) {
+					foreach (self::$supressDivisionProps as $pattern) {
+						if (preg_match($pattern, $this->env->currentProperty)) {
+							$this->env->supressedDivision = true;
+							break 2;
+						}
+					}
+				}
+
+
+				$whiteAfter = isset($this->buffer[$this->count - 1]) &&
+					ctype_space($this->buffer[$this->count - 1]);
+
+				if (!$this->value($rhs)) break;
+
+				// peek for next operator to see what to do with rhs
+				if ($this->peek(self::$operatorString, $next) && self::$precedence[$next[1]] > self::$precedence[$m[1]]) {
+					$rhs = $this->expHelper($rhs, self::$precedence[$next[1]]);
+				}
+
+				$lhs = array('expression', $m[1], $lhs, $rhs, $whiteBefore, $whiteAfter);
+				$ss = $this->seek();
+
+				continue;
+			}
+
+			break;
+		}
+
+		$this->seek($ss);
+
+		return $lhs;
+	}
+
+	// consume a list of values for a property
+	public function propertyValue(&$value, $keyName = null) {
+		$values = array();
+
+		if ($keyName !== null) $this->env->currentProperty = $keyName;
+
+		$s = null;
+		while ($this->expressionList($v)) {
+			$values[] = $v;
+			$s = $this->seek();
+			if (!$this->literal(',')) break;
+		}
+
+		if ($s) $this->seek($s);
+
+		if ($keyName !== null) unset($this->env->currentProperty);
+
+		if (count($values) == 0) return false;
+
+		$value = lessc::compressList($values, ', ');
+		return true;
+	}
+
+	protected function parenValue(&$out) {
+		$s = $this->seek();
+
+		// speed shortcut
+		if (isset($this->buffer[$this->count]) && $this->buffer[$this->count] != "(") {
+			return false;
+		}
+
+		$inParens = $this->inParens;
+		if ($this->literal("(") &&
+			($this->inParens = true) && $this->expression($exp) &&
+			$this->literal(")"))
+		{
+			$out = $exp;
+			$this->inParens = $inParens;
+			return true;
+		} else {
+			$this->inParens = $inParens;
+			$this->seek($s);
+		}
+
+		return false;
+	}
+
+	// a single value
+	protected function value(&$value) {
+		$s = $this->seek();
+
+		// speed shortcut
+		if (isset($this->buffer[$this->count]) && $this->buffer[$this->count] == "-") {
+			// negation
+			if ($this->literal("-", false) &&
+				(($this->variable($inner) && $inner = array("variable", $inner)) ||
+				$this->unit($inner) ||
+				$this->parenValue($inner)))
+			{
+				$value = array("unary", "-", $inner);
+				return true;
+			} else {
+				$this->seek($s);
+			}
+		}
+
+		if ($this->parenValue($value)) return true;
+		if ($this->unit($value)) return true;
+		if ($this->color($value)) return true;
+		if ($this->func($value)) return true;
+		if ($this->string($value)) return true;
+
+		if ($this->keyword($word)) {
+			$value = array('keyword', $word);
+			return true;
+		}
+
+		// try a variable
+		if ($this->variable($var)) {
+			$value = array('variable', $var);
+			return true;
+		}
+
+		// unquote string (should this work on any type?
+		if ($this->literal("~") && $this->string($str)) {
+			$value = array("escape", $str);
+			return true;
+		} else {
+			$this->seek($s);
+		}
+
+		// css hack: \0
+		if ($this->literal('\\') && $this->match('([0-9]+)', $m)) {
+			$value = array('keyword', '\\'.$m[1]);
+			return true;
+		} else {
+			$this->seek($s);
+		}
+
+		return false;
+	}
+
+	// an import statement
+	protected function import(&$out) {
+		$s = $this->seek();
+		if (!$this->literal('@import')) return false;
+
+		// @import "something.css" media;
+		// @import url("something.css") media;
+		// @import url(something.css) media;
+
+		if ($this->propertyValue($value)) {
+			$out = array("import", $value);
+			return true;
+		}
+	}
+
+	protected function mediaQueryList(&$out) {
+		if ($this->genericList($list, "mediaQuery", ",", false)) {
+			$out = $list[2];
+			return true;
+		}
+		return false;
+	}
+
+	protected function mediaQuery(&$out) {
+		$s = $this->seek();
+
+		$expressions = null;
+		$parts = array();
+
+		if (($this->literal("only") && ($only = true) || $this->literal("not") && ($not = true) || true) && $this->keyword($mediaType)) {
+			$prop = array("mediaType");
+			if (isset($only)) $prop[] = "only";
+			if (isset($not)) $prop[] = "not";
+			$prop[] = $mediaType;
+			$parts[] = $prop;
+		} else {
+			$this->seek($s);
+		}
+
+
+		if (!empty($mediaType) && !$this->literal("and")) {
+			// ~
+		} else {
+			$this->genericList($expressions, "mediaExpression", "and", false);
+			if (is_array($expressions)) $parts = array_merge($parts, $expressions[2]);
+		}
+
+		if (count($parts) == 0) {
+			$this->seek($s);
+			return false;
+		}
+
+		$out = $parts;
+		return true;
+	}
+
+	protected function mediaExpression(&$out) {
+		$s = $this->seek();
+		$value = null;
+		if ($this->literal("(") &&
+			$this->keyword($feature) &&
+			($this->literal(":") && $this->expression($value) || true) &&
+			$this->literal(")"))
+		{
+			$out = array("mediaExp", $feature);
+			if ($value) $out[] = $value;
+			return true;
+		}
+
+		$this->seek($s);
+		return false;
+	}
+
+	// an unbounded string stopped by $end
+	protected function openString($end, &$out, $nestingOpen=null, $rejectStrs = null) {
+		$oldWhite = $this->eatWhiteDefault;
+		$this->eatWhiteDefault = false;
+
+		$stop = array("'", '"', "@{", $end);
+		$stop = array_map(array("lessc", "preg_quote"), $stop);
+		// $stop[] = self::$commentMulti;
+
+		if (!is_null($rejectStrs)) {
+			$stop = array_merge($stop, $rejectStrs);
+		}
+
+		$patt = '(.*?)('.implode("|", $stop).')';
+
+		$nestingLevel = 0;
+
+		$content = array();
+		while ($this->match($patt, $m, false)) {
+			if (!empty($m[1])) {
+				$content[] = $m[1];
+				if ($nestingOpen) {
+					$nestingLevel += substr_count($m[1], $nestingOpen);
+				}
+			}
+
+			$tok = $m[2];
+
+			$this->count-= strlen($tok);
+			if ($tok == $end) {
+				if ($nestingLevel == 0) {
+					break;
+				} else {
+					$nestingLevel--;
+				}
+			}
+
+			if (($tok == "'" || $tok == '"') && $this->string($str)) {
+				$content[] = $str;
+				continue;
+			}
+
+			if ($tok == "@{" && $this->interpolation($inter)) {
+				$content[] = $inter;
+				continue;
+			}
+
+			if (in_array($tok, $rejectStrs)) {
+				$count = null;
+				break;
+			}
+
+
+			$content[] = $tok;
+			$this->count+= strlen($tok);
+		}
+
+		$this->eatWhiteDefault = $oldWhite;
+
+		if (count($content) == 0) return false;
+
+		// trim the end
+		if (is_string(end($content))) {
+			$content[count($content) - 1] = rtrim(end($content));
+		}
+
+		$out = array("string", "", $content);
+		return true;
+	}
+
+	protected function string(&$out) {
+		$s = $this->seek();
+		if ($this->literal('"', false)) {
+			$delim = '"';
+		} elseif ($this->literal("'", false)) {
+			$delim = "'";
+		} else {
+			return false;
+		}
+
+		$content = array();
+
+		// look for either ending delim , escape, or string interpolation
+		$patt = '([^\n]*?)(@\{|\\\\|' .
+			lessc::preg_quote($delim).')';
+
+		$oldWhite = $this->eatWhiteDefault;
+		$this->eatWhiteDefault = false;
+
+		while ($this->match($patt, $m, false)) {
+			$content[] = $m[1];
+			if ($m[2] == "@{") {
+				$this->count -= strlen($m[2]);
+				if ($this->interpolation($inter, false)) {
+					$content[] = $inter;
+				} else {
+					$this->count += strlen($m[2]);
+					$content[] = "@{"; // ignore it
+				}
+			} elseif ($m[2] == '\\') {
+				$content[] = $m[2];
+				if ($this->literal($delim, false)) {
+					$content[] = $delim;
+				}
+			} else {
+				$this->count -= strlen($delim);
+				break; // delim
+			}
+		}
+
+		$this->eatWhiteDefault = $oldWhite;
+
+		if ($this->literal($delim)) {
+			$out = array("string", $delim, $content);
+			return true;
+		}
+
+		$this->seek($s);
+		return false;
+	}
+
+	protected function interpolation(&$out) {
+		$oldWhite = $this->eatWhiteDefault;
+		$this->eatWhiteDefault = true;
+
+		$s = $this->seek();
+		if ($this->literal("@{") &&
+			$this->keyword($var) &&
+			$this->literal("}", false))
+		{
+			$out = array("variable", $this->lessc->vPrefix . $var);
+			$this->eatWhiteDefault = $oldWhite;
+			if ($this->eatWhiteDefault) $this->whitespace();
+			return true;
+		}
+
+		$this->eatWhiteDefault = $oldWhite;
+		$this->seek($s);
+		return false;
+	}
+
+	protected function unit(&$unit) {
+		// speed shortcut
+		if (isset($this->buffer[$this->count])) {
+			$char = $this->buffer[$this->count];
+			if (!ctype_digit($char) && $char != ".") return false;
+		}
+
+		if ($this->match('([0-9]+(?:\.[0-9]*)?|\.[0-9]+)([%a-zA-Z]+)?', $m)) {
+			$unit = array("number", $m[1], empty($m[2]) ? "" : $m[2]);
+			return true;
+		}
+		return false;
+	}
+
+	// a # color
+	protected function color(&$out) {
+		if ($this->match('(#(?:[0-9a-f]{8}|[0-9a-f]{6}|[0-9a-f]{3}))', $m)) {
+			if (strlen($m[1]) > 7) {
+				$out = array("string", "", array($m[1]));
+			} else {
+				$out = array("raw_color", $m[1]);
+			}
+			return true;
+		}
+
+		return false;
+	}
+
+	// consume a list of property values delimited by ; and wrapped in ()
+	protected function argumentValues(&$args, $delim = ',') {
+		$s = $this->seek();
+		if (!$this->literal('(')) return false;
+
+		$values = array();
+		while (true) {
+			if ($this->expressionList($value)) $values[] = $value;
+			if (!$this->literal($delim)) break;
+			else {
+				if ($value == null) $values[] = null;
+				$value = null;
+			}
+		}
+
+		if (!$this->literal(')')) {
+			$this->seek($s);
+			return false;
+		}
+
+		$args = $values;
+		return true;
+	}
+
+	// consume an argument definition list surrounded by ()
+	// each argument is a variable name with optional value
+	// or at the end a ... or a variable named followed by ...
+	protected function argumentDef(&$args, &$isVararg, $delim = ',') {
+		$s = $this->seek();
+		if (!$this->literal('(')) return false;
+
+		$values = array();
+
+		$isVararg = false;
+		while (true) {
+			if ($this->literal("...")) {
+				$isVararg = true;
+				break;
+			}
+
+			if ($this->variable($vname)) {
+				$arg = array("arg", $vname);
+				$ss = $this->seek();
+				if ($this->assign() && $this->expressionList($value)) {
+					$arg[] = $value;
+				} else {
+					$this->seek($ss);
+					if ($this->literal("...")) {
+						$arg[0] = "rest";
+						$isVararg = true;
+					}
+				}
+				$values[] = $arg;
+				if ($isVararg) break;
+				continue;
+			}
+
+			if ($this->value($literal)) {
+				$values[] = array("lit", $literal);
+			}
+
+			if (!$this->literal($delim)) break;
+		}
+
+		if (!$this->literal(')')) {
+			$this->seek($s);
+			return false;
+		}
+
+		$args = $values;
+
+		return true;
+	}
+
+	// consume a list of tags
+	// this accepts a hanging delimiter
+	protected function tags(&$tags, $simple = false, $delim = ',') {
+		$tags = array();
+		while ($this->tag($tt, $simple)) {
+			$tags[] = $tt;
+			if (!$this->literal($delim)) break;
+		}
+		if (count($tags) == 0) return false;
+
+		return true;
+	}
+
+	// list of tags of specifying mixin path
+	// optionally separated by > (lazy, accepts extra >)
+	protected function mixinTags(&$tags) {
+		$s = $this->seek();
+		$tags = array();
+		while ($this->tag($tt, true)) {
+			$tags[] = $tt;
+			$this->literal(">");
+		}
+
+		if (count($tags) == 0) return false;
+
+		return true;
+	}
+
+	// a bracketed value (contained within in a tag definition)
+	protected function tagBracket(&$value) {
+		// speed shortcut
+		if (isset($this->buffer[$this->count]) && $this->buffer[$this->count] != "[") {
+			return false;
+		}
+
+		$s = $this->seek();
+		if ($this->literal('[') && $this->to(']', $c, true) && $this->literal(']', false)) {
+			$value = '['.$c.']';
+			// whitespace?
+			if ($this->whitespace()) $value .= " ";
+
+			// escape parent selector, (yuck)
+			$value = str_replace($this->lessc->parentSelector, "$&$", $value);
+			return true;
+		}
+
+		$this->seek($s);
+		return false;
+	}
+
+	protected function tagExpression(&$value) {
+		$s = $this->seek();
+		if ($this->literal("(") && $this->expression($exp) && $this->literal(")")) {
+			$value = array('exp', $exp);
+			return true;
+		}
+
+		$this->seek($s);
+		return false;
+	}
+
+	// a single tag
+	protected function tag(&$tag, $simple = false) {
+		if ($simple)
+			$chars = '^,:;{}\][>\(\) "\'';
+		else
+			$chars = '^,;{}["\'';
+
+		if (!$simple && $this->tagExpression($tag)) {
+			return true;
+		}
+
+		$tag = '';
+		while ($this->tagBracket($first)) $tag .= $first;
+
+		while (true) {
+			if ($this->match('(['.$chars.'0-9]['.$chars.']*)', $m)) {
+				$tag .= $m[1];
+				if ($simple) break;
+
+				while ($this->tagBracket($brack)) $tag .= $brack;
+				continue;
+			} elseif ($this->unit($unit)) { // for keyframes
+				$tag .= $unit[1] . $unit[2];
+				continue;
+			}
+			break;
+		}
+
+
+		$tag = trim($tag);
+		if ($tag == '') return false;
+
+		return true;
+	}
+
+	// a css function
+	protected function func(&$func) {
+		$s = $this->seek();
+
+		if ($this->match('(%|[\w\-_][\w\-_:\.]+|[\w_])', $m) && $this->literal('(')) {
+			$fname = $m[1];
+
+			$sPreArgs = $this->seek();
+
+			$args = array();
+			while (true) {
+				$ss = $this->seek();
+				// this ugly nonsense is for ie filter properties
+				if ($this->keyword($name) && $this->literal('=') && $this->expressionList($value)) {
+					$args[] = array("string", "", array($name, "=", $value));
+				} else {
+					$this->seek($ss);
+					if ($this->expressionList($value)) {
+						$args[] = $value;
+					}
+				}
+
+				if (!$this->literal(',')) break;
+			}
+			$args = array('list', ',', $args);
+
+			if ($this->literal(')')) {
+				$func = array('function', $fname, $args);
+				return true;
+			} elseif ($fname == 'url') {
+				// couldn't parse and in url? treat as string
+				$this->seek($sPreArgs);
+				if ($this->openString(")", $string) && $this->literal(")")) {
+					$func = array('function', $fname, $string);
+					return true;
+				}
+			}
+		}
+
+		$this->seek($s);
+		return false;
+	}
+
+	// consume a less variable
+	protected function variable(&$name) {
+		$s = $this->seek();
+		if ($this->literal($this->lessc->vPrefix, false) &&
+			($this->variable($sub) || $this->keyword($name)))
+		{
+			if (!empty($sub)) {
+				$name = array('variable', $sub);
+			} else {
+				$name = $this->lessc->vPrefix.$name;
+			}
+			return true;
+		}
+
+		$name = null;
+		$this->seek($s);
+		return false;
+	}
+
+	/**
+	 * Consume an assignment operator
+	 * Can optionally take a name that will be set to the current property name
+	 */
+	protected function assign($name = null) {
+		if ($name) $this->currentProperty = $name;
+		return $this->literal(':') || $this->literal('=');
+	}
+
+	// consume a keyword
+	protected function keyword(&$word) {
+		if ($this->match('([\w_\-\*!"][\w\-_"]*)', $m)) {
+			$word = $m[1];
+			return true;
+		}
+		return false;
+	}
+
+	// consume an end of statement delimiter
+	protected function end() {
+		if ($this->literal(';')) {
+			return true;
+		} elseif ($this->count == strlen($this->buffer) || $this->buffer{$this->count} == '}') {
+			// if there is end of file or a closing block next then we don't need a ;
+			return true;
+		}
+		return false;
+	}
+
+	protected function guards(&$guards) {
+		$s = $this->seek();
+
+		if (!$this->literal("when")) {
+			$this->seek($s);
+			return false;
+		}
+
+		$guards = array();
+
+		while ($this->guardGroup($g)) {
+			$guards[] = $g;
+			if (!$this->literal(",")) break;
+		}
+
+		if (count($guards) == 0) {
+			$guards = null;
+			$this->seek($s);
+			return false;
+		}
+
+		return true;
+	}
+
+	// a bunch of guards that are and'd together
+	// TODO rename to guardGroup
+	protected function guardGroup(&$guardGroup) {
+		$s = $this->seek();
+		$guardGroup = array();
+		while ($this->guard($guard)) {
+			$guardGroup[] = $guard;
+			if (!$this->literal("and")) break;
+		}
+
+		if (count($guardGroup) == 0) {
+			$guardGroup = null;
+			$this->seek($s);
+			return false;
+		}
+
+		return true;
+	}
+
+	protected function guard(&$guard) {
+		$s = $this->seek();
+		$negate = $this->literal("not");
+
+		if ($this->literal("(") && $this->expression($exp) && $this->literal(")")) {
+			$guard = $exp;
+			if ($negate) $guard = array("negate", $guard);
+			return true;
+		}
+
+		$this->seek($s);
+		return false;
+	}
+
+	/* raw parsing functions */
+
+	protected function literal($what, $eatWhitespace = null) {
+		if ($eatWhitespace === null) $eatWhitespace = $this->eatWhiteDefault;
+
+		// shortcut on single letter
+		if (!isset($what[1]) && isset($this->buffer[$this->count])) {
+			if ($this->buffer[$this->count] == $what) {
+				if (!$eatWhitespace) {
+					$this->count++;
+					return true;
+				}
+				// goes below...
+			} else {
+				return false;
+			}
+		}
+
+		if (!isset(self::$literalCache[$what])) {
+			self::$literalCache[$what] = lessc::preg_quote($what);
+		}
+
+		return $this->match(self::$literalCache[$what], $m, $eatWhitespace);
+	}
+
+	protected function genericList(&$out, $parseItem, $delim="", $flatten=true) {
+		$s = $this->seek();
+		$items = array();
+		while ($this->$parseItem($value)) {
+			$items[] = $value;
+			if ($delim) {
+				if (!$this->literal($delim)) break;
+			}
+		}
+
+		if (count($items) == 0) {
+			$this->seek($s);
+			return false;
+		}
+
+		if ($flatten && count($items) == 1) {
+			$out = $items[0];
+		} else {
+			$out = array("list", $delim, $items);
+		}
+
+		return true;
+	}
+
+
+	// advance counter to next occurrence of $what
+	// $until - don't include $what in advance
+	// $allowNewline, if string, will be used as valid char set
+	protected function to($what, &$out, $until = false, $allowNewline = false) {
+		if (is_string($allowNewline)) {
+			$validChars = $allowNewline;
+		} else {
+			$validChars = $allowNewline ? "." : "[^\n]";
+		}
+		if (!$this->match('('.$validChars.'*?)'.lessc::preg_quote($what), $m, !$until)) return false;
+		if ($until) $this->count -= strlen($what); // give back $what
+		$out = $m[1];
+		return true;
+	}
+
+	// try to match something on head of buffer
+	protected function match($regex, &$out, $eatWhitespace = null) {
+		if ($eatWhitespace === null) $eatWhitespace = $this->eatWhiteDefault;
+
+		$r = '/'.$regex.($eatWhitespace && !$this->writeComments ? '\s*' : '').'/Ais';
+		if (preg_match($r, $this->buffer, $out, null, $this->count)) {
+			$this->count += strlen($out[0]);
+			if ($eatWhitespace && $this->writeComments) $this->whitespace();
+			return true;
+		}
+		return false;
+	}
+
+	// match some whitespace
+	protected function whitespace() {
+		if ($this->writeComments) {
+			$gotWhite = false;
+			while (preg_match(self::$whitePattern, $this->buffer, $m, null, $this->count)) {
+				if (isset($m[1]) && empty($this->commentsSeen[$this->count])) {
+					$this->append(array("comment", $m[1]));
+					$this->commentsSeen[$this->count] = true;
+				}
+				$this->count += strlen($m[0]);
+				$gotWhite = true;
+			}
+			return $gotWhite;
+		} else {
+			$this->match("", $m);
+			return strlen($m[0]) > 0;
+		}
+	}
+
+	// match something without consuming it
+	protected function peek($regex, &$out = null, $from=null) {
+		if (is_null($from)) $from = $this->count;
+		$r = '/'.$regex.'/Ais';
+		$result = preg_match($r, $this->buffer, $out, null, $from);
+
+		return $result;
+	}
+
+	// seek to a spot in the buffer or return where we are on no argument
+	protected function seek($where = null) {
+		if ($where === null) return $this->count;
+		else $this->count = $where;
+		return true;
+	}
+
+	/* misc functions */
+
+	public function throwError($msg = "parse error", $count = null) {
+		$count = is_null($count) ? $this->count : $count;
+
+		$line = $this->line +
+			substr_count(substr($this->buffer, 0, $count), "\n");
+
+		if (!empty($this->sourceName)) {
+			$loc = "$this->sourceName on line $line";
+		} else {
+			$loc = "line: $line";
+		}
+
+		// TODO this depends on $this->count
+		if ($this->peek("(.*?)(\n|$)", $m, $count)) {
+			throw new exception("$msg: failed at `$m[1]` $loc");
+		} else {
+			throw new exception("$msg: $loc");
+		}
+	}
+
+	protected function pushBlock($selectors=null, $type=null) {
+		$b = new stdclass;
+		$b->parent = $this->env;
+
+		$b->type = $type;
+		$b->id = self::$nextBlockId++;
+
+		$b->isVararg = false; // TODO: kill me from here
+		$b->tags = $selectors;
+
+		$b->props = array();
+		$b->children = array();
+
+		$this->env = $b;
+		return $b;
+	}
+
+	// push a block that doesn't multiply tags
+	protected function pushSpecialBlock($type) {
+		return $this->pushBlock(null, $type);
+	}
+
+	// append a property to the current block
+	protected function append($prop, $pos = null) {
+		if ($pos !== null) $prop[-1] = $pos;
+		$this->env->props[] = $prop;
+	}
+
+	// pop something off the stack
+	protected function pop() {
+		$old = $this->env;
+		$this->env = $this->env->parent;
+		return $old;
+	}
+
+	// remove comments from $text
+	// todo: make it work for all functions, not just url
+	protected function removeComments($text) {
+		$look = array(
+			'url(', '//', '/*', '"', "'"
+		);
+
+		$out = '';
+		$min = null;
+		while (true) {
+			// find the next item
+			foreach ($look as $token) {
+				$pos = strpos($text, $token);
+				if ($pos !== false) {
+					if (!isset($min) || $pos < $min[1]) $min = array($token, $pos);
+				}
+			}
+
+			if (is_null($min)) break;
+
+			$count = $min[1];
+			$skip = 0;
+			$newlines = 0;
+			switch ($min[0]) {
+			case 'url(':
+				if (preg_match('/url\(.*?\)/', $text, $m, 0, $count))
+					$count += strlen($m[0]) - strlen($min[0]);
+				break;
+			case '"':
+			case "'":
+				if (preg_match('/'.$min[0].'.*?'.$min[0].'/', $text, $m, 0, $count))
+					$count += strlen($m[0]) - 1;
+				break;
+			case '//':
+				$skip = strpos($text, "\n", $count);
+				if ($skip === false) $skip = strlen($text) - $count;
+				else $skip -= $count;
+				break;
+			case '/*':
+				if (preg_match('/\/\*.*?\*\//s', $text, $m, 0, $count)) {
+					$skip = strlen($m[0]);
+					$newlines = substr_count($m[0], "\n");
+				}
+				break;
+			}
+
+			if ($skip == 0) $count += strlen($min[0]);
+
+			$out .= substr($text, 0, $count).str_repeat("\n", $newlines);
+			$text = substr($text, $count + $skip);
+
+			$min = null;
+		}
+
+		return $out.$text;
+	}
+
+}
+
+class lessc_formatter_classic {
+	public $indentChar = "  ";
+
+	public $break = "\n";
+	public $open = " {";
+	public $close = "}";
+	public $selectorSeparator = ", ";
+	public $assignSeparator = ":";
+
+	public $openSingle = " { ";
+	public $closeSingle = " }";
+
+	public $disableSingle = false;
+	public $breakSelectors = false;
+
+	public $compressColors = false;
+
+	public function __construct() {
+		$this->indentLevel = 0;
+	}
+
+	public function indentStr($n = 0) {
+		return str_repeat($this->indentChar, max($this->indentLevel + $n, 0));
+	}
+
+	public function property($name, $value) {
+		return $name . $this->assignSeparator . $value . ";";
+	}
+
+	protected function isEmpty($block) {
+		if (empty($block->lines)) {
+			foreach ($block->children as $child) {
+				if (!$this->isEmpty($child)) return false;
+			}
+
+			return true;
+		}
+		return false;
+	}
+
+	public function block($block) {
+		if ($this->isEmpty($block)) return;
+
+		$inner = $pre = $this->indentStr();
+
+		$isSingle = !$this->disableSingle &&
+			is_null($block->type) && count($block->lines) == 1;
+
+		if (!empty($block->selectors)) {
+			$this->indentLevel++;
+
+			if ($this->breakSelectors) {
+				$selectorSeparator = $this->selectorSeparator . $this->break . $pre;
+			} else {
+				$selectorSeparator = $this->selectorSeparator;
+			}
+
+			echo $pre .
+				implode($selectorSeparator, $block->selectors);
+			if ($isSingle) {
+				echo $this->openSingle;
+				$inner = "";
+			} else {
+				echo $this->open . $this->break;
+				$inner = $this->indentStr();
+			}
+
+		}
+
+		if (!empty($block->lines)) {
+			$glue = $this->break.$inner;
+			echo $inner . implode($glue, $block->lines);
+			if (!$isSingle && !empty($block->children)) {
+				echo $this->break;
+			}
+		}
+
+		foreach ($block->children as $child) {
+			$this->block($child);
+		}
+
+		if (!empty($block->selectors)) {
+			if (!$isSingle && empty($block->children)) echo $this->break;
+
+			if ($isSingle) {
+				echo $this->closeSingle . $this->break;
+			} else {
+				echo $pre . $this->close . $this->break;
+			}
+
+			$this->indentLevel--;
+		}
+	}
+}
+
+class lessc_formatter_compressed extends lessc_formatter_classic {
+	public $disableSingle = true;
+	public $open = "{";
+	public $selectorSeparator = ",";
+	public $assignSeparator = ":";
+	public $break = "";
+	public $compressColors = true;
+
+	public function indentStr($n = 0) {
+		return "";
+	}
+}
+
+class lessc_formatter_lessjs extends lessc_formatter_classic {
+	public $disableSingle = true;
+	public $breakSelectors = true;
+	public $assignSeparator = ": ";
+	public $selectorSeparator = ",";
+}