Update to MediaWiki 1.25.1

1 files changed, 3768 insertions, 0 deletions

diff --git a/vendor/leafo/lessphp/lessc.inc.php b/vendor/leafo/lessphp/lessc.inc.php
new file mode 100644
index 00000000..2292f219
--- /dev/null
+++ b/vendor/leafo/lessphp/lessc.inc.php
@@ -0,0 +1,3768 @@
+<?php
+
+/**
+ * lessphp v0.5.0
+ * http://leafo.net/lessphp
+ *
+ * LESS CSS compiler, adapted from http://lesscss.org
+ *
+ * Copyright 2013, Leaf Corcoran <leafot@gmail.com>
+ * Licensed under MIT or GPLv3, see LICENSE
+ */
+
+
+/**
+ * The LESS compiler and parser.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * The `parse` function of `lessc` is the entry point.
+ *
+ * In summary:
+ *
+ * The `lessc` class creates an instance 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 {
+	static public $VERSION = "v0.5.0";
+
+	static public $TRUE = array("keyword", "true");
+	static public $FALSE = array("keyword", "false");
+
+	protected $libFunctions = array();
+	protected $registeredVars = array();
+	protected $preserveComments = false;
+
+	public $vPrefix = '@'; // prefix of abstract properties
+	public $mPrefix = '$'; // prefix of abstract blocks
+	public $parentSelector = '&';
+
+	public $importDisabled = false;
+	public $importDir = '';
+
+	protected $numberPrecision = null;
+
+	protected $allParsedFiles = array();
+
+	// 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;
+
+	static protected $nextImportId = 0; // uniquely identify imports
+
+	// attempts to find the path of an import url, returns null for css files
+	protected function findImport($url) {
+		foreach ((array)$this->importDir as $dir) {
+			$full = $dir.(substr($dir, -1) != '/' ? '/' : '').$url;
+			if ($this->fileExists($file = $full.'.less') || $this->fileExists($file = $full)) {
+				return $file;
+			}
+		}
+
+		return null;
+	}
+
+	protected function fileExists($name) {
+		return is_file($name);
+	}
+
+	static public function compressList($items, $delim) {
+		if (!isset($items[1]) && isset($items[0])) return $items[0];
+		else return array('list', $delim, $items);
+	}
+
+	static public function preg_quote($what) {
+		return preg_quote($what, '/');
+	}
+
+	protected function tryImport($importPath, $parentBlock, $out) {
+		if ($importPath[0] == "function" && $importPath[1] == "url") {
+			$importPath = $this->flattenList($importPath[2]);
+		}
+
+		$str = $this->coerceString($importPath);
+		if ($str === null) return false;
+
+		$url = $this->compileValue($this->lib_e($str));
+
+		// don't import if it ends in css
+		if (substr_compare($url, '.css', -4, 4) === 0) return false;
+
+		$realPath = $this->findImport($url);
+
+		if ($realPath === null) return false;
+
+		if ($this->importDisabled) {
+			return array(false, "/* import disabled */");
+		}
+
+		if (isset($this->allParsedFiles[realpath($realPath)])) {
+			return array(false, null);
+		}
+
+		$this->addParsedFile($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 = $parentBlock;
+			}
+		}
+
+		// copy mixins into scope, set their parents
+		// bring blocks from import into current block
+		// TODO: need to mark the source parser	these came from this file
+		foreach ($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 = $oldSourceParser;
+	}
+
+	/**
+	 * Recursively compiles a block.
+	 *
+	 * A block is analogous to a CSS block in most cases. A single LESS document
+	 * is encapsulated in a block when parsed, but it does not have parent tags
+	 * so all of it's children appear on the root level when compiled.
+	 *
+	 * Blocks are made up of props and children.
+	 *
+	 * Props are property instructions, array tuples which describe an action
+	 * to be taken, eg. write a property, set a variable, mixin a block.
+	 *
+	 * The children of a block are just all the blocks that are defined within.
+	 * This is used to look up mixins when performing a mixin.
+	 *
+	 * Compiling the block involves pushing a fresh environment on the stack,
+	 * and iterating through the props, compiling each one.
+	 *
+	 * See lessc::compileProp()
+	 *
+	 */
+	protected function compileBlock($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));
+			}
+
+			$this->compileNestedBlock($block, array($name));
+			break;
+		default:
+			$this->throwError("unknown block type: $block->type\n");
+		}
+	}
+
+	protected function compileCSSBlock($block) {
+		$env = $this->pushEnv();
+
+		$selectors = $this->compileSelectors($block->tags);
+		$env->selectors = $this->multiplySelectors($selectors);
+		$out = $this->makeOutputBlock(null, $env->selectors);
+
+		$this->scope->children[] = $out;
+		$this->compileProps($block, $out);
+
+		$block->scope = $env; // mixins carry scope with them!
+		$this->popEnv();
+	}
+
+	protected function compileMedia($media) {
+		$env = $this->pushEnv($media);
+		$parentScope = $this->mediaParent($this->scope);
+
+		$query = $this->compileMediaQuery($this->multiplyMedia($env));
+
+		$this->scope = $this->makeOutputBlock($media->type, array($query));
+		$parentScope->children[] = $this->scope;
+
+		$this->compileProps($media, $this->scope);
+
+		if (count($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);
+		}
+		$out->lines = $this->deduplicate($out->lines);
+	}
+
+	/**
+	 * Deduplicate lines in a block. Comments are not deduplicated. If a
+	 * duplicate rule is detected, the comments immediately preceding each
+	 * occurence are consolidated.
+	 */
+	protected function deduplicate($lines) {
+		$unique = array();
+		$comments = array();
+
+		foreach($lines as $line) {
+			if (strpos($line, '/*') === 0) {
+				$comments[] = $line;
+				continue;
+			}
+			if (!in_array($line, $unique)) {
+				$unique[] = $line;
+			}
+			array_splice($unique, array_search($line, $unique), 0, $comments);
+			$comments = array();
+		}
+		return array_merge($unique, $comments);
+	}
+
+	protected function sortProps($props, $split = false) {
+		$vars = array();
+		$imports = array();
+		$other = array();
+		$stack = array();
+
+		foreach ($props as $prop) {
+			switch ($prop[0]) {
+			case "comment":
+				$stack[] = $prop;
+				break;
+			case "assign":
+				$stack[] = $prop;
+				if (isset($prop[1][0]) && $prop[1][0] == $this->vPrefix) {
+					$vars = array_merge($vars, $stack);
+				} else {
+					$other = array_merge($other, $stack);
+				}
+				$stack = array();
+				break;
+			case "import":
+				$id = self::$nextImportId++;
+				$prop[] = $id;
+				$stack[] = $prop;
+				$imports = array_merge($imports, $stack);
+				$other[] = array("import_mixin", $id);
+				$stack = array();
+				break;
+			default:
+				$stack[] = $prop;
+				$other = array_merge($other, $stack);
+				$stack = array();
+				break;
+			}
+		}
+		$other = array_merge($other, $stack);
+
+		if ($split) {
+			return array(array_merge($imports, $vars), $other);
+		} else {
+			return array_merge($imports, $vars, $other);
+		}
+	}
+
+	protected function compileMediaQuery($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;
+				case "variable":
+					$parts[] = $this->compileValue($this->reduce($q));
+				break;
+				}
+			}
+
+			if (count($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 $this->multiplyMedia($env->parent, $out);
+	}
+
+	protected function expandParentSelectors(&$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;
+				$out[] = trim($this->compileValue($this->reduce($value)));
+			} else {
+				$out[] = $s;
+			}
+		}
+
+		return $out;
+	}
+
+	protected function eq($left, $right) {
+		return $left == $right;
+	}
+
+	protected function patternMatch($block, $orderedArgs, $keywordArgs) {
+		// match the guards if it has them
+		// any one of the groups must have all its guards pass for a match
+		if (!empty($block->guards)) {
+			$groupPassed = false;
+			foreach ($block->guards as $guardGroup) {
+				foreach ($guardGroup as $guard) {
+					$this->pushEnv();
+					$this->zipSetArgs($block->args, $orderedArgs, $keywordArgs);
+
+					$negate = false;
+					if ($guard[0] == "negate") {
+						$guard = $guard[1];
+						$negate = true;
+					}
+
+					$passed = $this->reduce($guard) == self::$TRUE;
+					if ($negate) $passed = !$passed;
+
+					$this->popEnv();
+
+					if ($passed) {
+						$groupPassed = true;
+					} else {
+						$groupPassed = false;
+						break;
+					}
+				}
+
+				if ($groupPassed) break;
+			}
+
+			if (!$groupPassed) {
+				return false;
+			}
+		}
+
+		if (empty($block->args)) {
+			return $block->isVararg || empty($orderedArgs) && empty($keywordArgs);
+		}
+
+		$remainingArgs = $block->args;
+		if ($keywordArgs) {
+			$remainingArgs = array();
+			foreach ($block->args as $arg) {
+				if ($arg[0] == "arg" && isset($keywordArgs[$arg[1]])) {
+					continue;
+				}
+
+				$remainingArgs[] = $arg;
+			}
+		}
+
+		$i = -1; // no args
+		// try to match by arity or by argument literal
+		foreach ($remainingArgs as $i => $arg) {
+			switch ($arg[0]) {
+			case "lit":
+				if (empty($orderedArgs[$i]) || !$this->eq($arg[1], $orderedArgs[$i])) {
+					return false;
+				}
+				break;
+			case "arg":
+				// no arg and no default value
+				if (!isset($orderedArgs[$i]) && !isset($arg[2])) {
+					return false;
+				}
+				break;
+			case "rest":
+				$i--; // rest can be empty
+				break 2;
+			}
+		}
+
+		if ($block->isVararg) {
+			return true; // not having enough is handled above
+		} else {
+			$numMatched = $i + 1;
+			// greater than becuase default values always match
+			return $numMatched >= count($orderedArgs);
+		}
+	}
+
+	protected function patternMatchAll($blocks, $orderedArgs, $keywordArgs, $skip=array()) {
+		$matches = null;
+		foreach ($blocks as $block) {
+			// skip seen blocks that don't have arguments
+			if (isset($skip[$block->id]) && !isset($block->args)) {
+				continue;
+			}
+
+			if ($this->patternMatch($block, $orderedArgs, $keywordArgs)) {
+				$matches[] = $block;
+			}
+		}
+
+		return $matches;
+	}
+
+	// attempt to find blocks matched by path and args
+	protected function findBlocks($searchIn, $path, $orderedArgs, $keywordArgs, $seen=array()) {
+		if ($searchIn == null) return null;
+		if (isset($seen[$searchIn->id])) return null;
+		$seen[$searchIn->id] = true;
+
+		$name = $path[0];
+
+		if (isset($searchIn->children[$name])) {
+			$blocks = $searchIn->children[$name];
+			if (count($path) == 1) {
+				$matches = $this->patternMatchAll($blocks, $orderedArgs, $keywordArgs, $seen);
+				if (!empty($matches)) {
+					// This will return all blocks that match in the closest
+					// scope that has any matching block, like lessjs
+					return $matches;
+				}
+			} else {
+				$matches = array();
+				foreach ($blocks as $subBlock) {
+					$subMatches = $this->findBlocks($subBlock,
+						array_slice($path, 1), $orderedArgs, $keywordArgs, $seen);
+
+					if (!is_null($subMatches)) {
+						foreach ($subMatches as $sm) {
+							$matches[] = $sm;
+						}
+					}
+				}
+
+				return count($matches) > 0 ? $matches : null;
+			}
+		}
+		if ($searchIn->parent === $searchIn) return null;
+		return $this->findBlocks($searchIn->parent, $path, $orderedArgs, $keywordArgs, $seen);
+	}
+
+	// sets all argument names in $args to either the default value
+	// or the one passed in through $values
+	protected function zipSetArgs($args, $orderedValues, $keywordValues) {
+		$assignedValues = array();
+
+		$i = 0;
+		foreach ($args as  $a) {
+			if ($a[0] == "arg") {
+				if (isset($keywordValues[$a[1]])) {
+					// has keyword arg
+					$value = $keywordValues[$a[1]];
+				} elseif (isset($orderedValues[$i])) {
+					// has ordered arg
+					$value = $orderedValues[$i];
+					$i++;
+				} elseif (isset($a[2])) {
+					// has default value
+					$value = $a[2];
+				} else {
+					$this->throwError("Failed to assign arg " . $a[1]);
+					$value = null; // :(
+				}
+
+				$value = $this->reduce($value);
+				$this->set($a[1], $value);
+				$assignedValues[] = $value;
+			} else {
+				// a lit
+				$i++;
+			}
+		}
+
+		// check for a rest
+		$last = end($args);
+		if ($last[0] == "rest") {
+			$rest = array_slice($orderedValues, count($args) - 1);
+			$this->set($last[1], $this->reduce(array("list", " ", $rest)));
+		}
+
+		// wow is this the only true use of PHP's + operator for arrays?
+		$this->env->arguments = $assignedValues + $orderedValues;
+	}
+
+	// compile a prop and update $lines or $blocks appropriately
+	protected function compileProp($prop, $block, $out) {
+		// set error position context
+		$this->sourceLoc = isset($prop[-1]) ? $prop[-1] : -1;
+
+		switch ($prop[0]) {
+		case 'assign':
+			list(, $name, $value) = $prop;
+			if ($name[0] == $this->vPrefix) {
+				$this->set($name, $value);
+			} else {
+				$out->lines[] = $this->formatter->property($name,
+						$this->compileValue($this->reduce($value)));
+			}
+			break;
+		case 'block':
+			list(, $child) = $prop;
+			$this->compileBlock($child);
+			break;
+		case 'mixin':
+			list(, $path, $args, $suffix) = $prop;
+
+			$orderedArgs = array();
+			$keywordArgs = array();
+			foreach ((array)$args as $arg) {
+				$argval = null;
+				switch ($arg[0]) {
+				case "arg":
+					if (!isset($arg[2])) {
+						$orderedArgs[] = $this->reduce(array("variable", $arg[1]));
+					} else {
+						$keywordArgs[$arg[1]] = $this->reduce($arg[2]);
+					}
+					break;
+
+				case "lit":
+					$orderedArgs[] = $this->reduce($arg[1]);
+					break;
+				default:
+					$this->throwError("Unknown arg type: " . $arg[0]);
+				}
+			}
+
+			$mixins = $this->findBlocks($block, $path, $orderedArgs, $keywordArgs);
+
+			if ($mixins === null) {
+				$this->throwError("{$prop[1][0]} is undefined");
+			}
+
+			foreach ($mixins as $mixin) {
+				if ($mixin === $block && !$orderedArgs) {
+					continue;
+				}
+
+				$haveScope = false;
+				if (isset($mixin->parent->scope)) {
+					$haveScope = true;
+					$mixinParentEnv = $this->pushEnv();
+					$mixinParentEnv->storeParent = $mixin->parent->scope;
+				}
+
+				$haveArgs = false;
+				if (isset($mixin->args)) {
+					$haveArgs = true;
+					$this->pushEnv();
+					$this->zipSetArgs($mixin->args, $orderedArgs, $keywordArgs);
+				}
+
+				$oldParent = $mixin->parent;
+				if ($mixin != $block) $mixin->parent = $block;
+
+				foreach ($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 = $oldParent;
+
+				if ($haveArgs) $this->popEnv();
+				if ($haveScope) $this->popEnv();
+			}
+
+			break;
+		case 'raw':
+			$out->lines[] = $prop[1];
+			break;
+		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 ($import[0] === false) {
+				if (isset($import[1])) {
+					$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");
+		}
+	}
+
+
+	/**
+	 * Compiles a primitive value into a CSS property value.
+	 *
+	 * Values in lessphp are typed by being wrapped in arrays, their format is
+	 * typically:
+	 *
+	 *     array(type, contents [, additional_contents]*)
+	 *
+	 * The input is expected to be reduced. This function will not work on
+	 * things like expressions and variables.
+	 */
+	public 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
+			return $value[1];
+		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)
+			list(, $delim, $content) = $value;
+			foreach ($content as &$part) {
+				if (is_array($part)) {
+					$part = $this->compileValue($part);
+				}
+			}
+			return $delim . implode($content) . $delim;
+		case 'color':
+			// [1] - red component (either number or a %)
+			// [2] - green component
+			// [3] - blue component
+			// [4] - optional alpha component
+			list(, $r, $g, $b) = $value;
+			$r = round($r);
+			$g = round($g);
+			$b = round($b);
+
+			if (count($value) == 5 && $value[4] != 1) { // rgba
+				return 'rgba('.$r.','.$g.','.$b.','.$value[4].')';
+			}
+
+			$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':
+			list(, $name, $args) = $value;
+			return $name.'('.$this->compileValue($args).')';
+		default: // assumed to be unit
+			$this->throwError("unknown value type: $value[0]");
+		}
+	}
+
+	protected function lib_pow($args) {
+		list($base, $exp) = $this->assertArgs($args, 2, "pow");
+		return pow($this->assertNumber($base), $this->assertNumber($exp));
+	}
+
+	protected function lib_pi() {
+		return pi();
+	}
+
+	protected function lib_mod($args) {
+		list($a, $b) = $this->assertArgs($args, 2, "mod");
+		return $this->assertNumber($a) % $this->assertNumber($b);
+	}
+
+	protected function lib_tan($num) {
+		return tan($this->assertNumber($num));
+	}
+
+	protected function lib_sin($num) {
+		return sin($this->assertNumber($num));
+	}
+
+	protected function lib_cos($num) {
+		return cos($this->assertNumber($num));
+	}
+
+	protected function lib_atan($num) {
+		$num = atan($this->assertNumber($num));
+		return array("number", $num, "rad");
+	}
+
+	protected function lib_asin($num) {
+		$num = asin($this->assertNumber($num));
+		return array("number", $num, "rad");
+	}
+
+	protected function lib_acos($num) {
+		$num = acos($this->assertNumber($num));
+		return array("number", $num, "rad");
+	}
+
+	protected function lib_sqrt($num) {
+		return sqrt($this->assertNumber($num));
+	}
+
+	protected function lib_extract($value) {
+		list($list, $idx) = $this->assertArgs($value, 2, "extract");
+		$idx = $this->assertNumber($idx);
+		// 1 indexed
+		if ($list[0] == "list" && isset($list[2][$idx - 1])) {
+			return $list[2][$idx - 1];
+		}
+	}
+
+	protected function lib_isnumber($value) {
+		return $this->toBool($value[0] == "number");
+	}
+
+	protected function lib_isstring($value) {
+		return $this->toBool($value[0] == "string");
+	}
+
+	protected function lib_iscolor($value) {
+		return $this->toBool($this->coerceColor($value));
+	}
+
+	protected function lib_iskeyword($value) {
+		return $this->toBool($value[0] == "keyword");
+	}
+
+	protected function lib_ispixel($value) {
+		return $this->toBool($value[0] == "number" && $value[2] == "px");
+	}
+
+	protected function lib_ispercentage($value) {
+		return $this->toBool($value[0] == "number" && $value[2] == "%");
+	}
+
+	protected function lib_isem($value) {
+		return $this->toBool($value[0] == "number" && $value[2] == "em");
+	}
+
+	protected function lib_isrem($value) {
+		return $this->toBool($value[0] == "number" && $value[2] == "rem");
+	}
+
+	protected function lib_rgbahex($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 : 255,
+			$color[1],$color[2], $color[3]);
+	}
+
+	protected function lib_argb($color){
+		return $this->lib_rgbahex($color);
+	}
+
+	/**
+	 * Given an url, decide whether to output a regular link or the base64-encoded contents of the file
+	 *
+	 * @param  array  $value either an argument list (two strings) or a single string
+	 * @return string        formatted url(), either as a link or base64-encoded
+	 */
+	protected function lib_data_uri($value) {
+		$mime = ($value[0] === 'list') ? $value[2][0][2] : null;
+		$url = ($value[0] === 'list') ? $value[2][1][2][0] : $value[2][0];
+
+		$fullpath = $this->findImport($url);
+
+		if($fullpath && ($fsize = filesize($fullpath)) !== false) {
+			// IE8 can't handle data uris larger than 32KB
+			if($fsize/1024 < 32) {
+				if(is_null($mime)) {
+					if(class_exists('finfo')) { // php 5.3+
+						$finfo = new finfo(FILEINFO_MIME);
+						$mime = explode('; ', $finfo->file($fullpath));
+						$mime = $mime[0];
+					} elseif(function_exists('mime_content_type')) { // PHP 5.2
+						$mime = mime_content_type($fullpath);
+					}
+				}
+
+				if(!is_null($mime)) // fallback if the mime type is still unknown
+					$url = sprintf('data:%s;base64,%s', $mime, base64_encode(file_get_contents($fullpath)));
+			}
+		}
+
+		return 'url("'.$url.'")';
+	}
+
+	// utility func to unquote a string
+	protected function lib_e($arg) {
+		switch ($arg[0]) {
+			case "list":
+				$items = $arg[2];
+				if (isset($items[0])) {
+					return $this->lib_e($items[0]);
+				}
+				$this->throwError("unrecognised input");
+			case "string":
+				$arg[1] = "";
+				return $arg;
+			case "keyword":
+				return $arg;
+			default:
+				return array("keyword", $this->compileValue($arg));
+		}
+	}
+
+	protected function lib__sprintf($args) {
+		if ($args[0] != "list") return $args;
+		$values = $args[2];
+		$string = array_shift($values);
+		$template = $this->compileValue($this->lib_e($string));
+
+		$i = 0;
+		if (preg_match_all('/%[dsa]/', $template, $m)) {
+			foreach ($m[0] as $match) {
+				$val = isset($values[$i]) ?
+					$this->reduce($values[$i]) : array('keyword', '');
+
+				// lessjs compat, renders fully expanded color, not raw color
+				if ($color = $this->coerceColor($val)) {
+					$val = $color;
+				}
+
+				$i++;
+				$rep = $this->compileValue($this->lib_e($val));
+				$template = preg_replace('/'.self::preg_quote($match).'/',
+					$rep, $template, 1);
+			}
+		}
+
+		$d = $string[0] == "string" ? $string[1] : '"';
+		return array("string", $d, array($template));
+	}
+
+	protected function lib_floor($arg) {
+		$value = $this->assertNumber($arg);
+		return array("number", floor($value), $arg[2]);
+	}
+
+	protected function lib_ceil($arg) {
+		$value = $this->assertNumber($arg);
+		return array("number", ceil($value), $arg[2]);
+	}
+
+	protected function lib_round($arg) {
+		if($arg[0] != "list") {
+			$value = $this->assertNumber($arg);
+			return array("number", round($value), $arg[2]);
+		} else {
+			$value = $this->assertNumber($arg[2][0]);
+			$precision = $this->assertNumber($arg[2][1]);
+			return array("number", round($value, $precision), $arg[2][0][2]);
+		}
+	}
+
+	protected function lib_unit($arg) {
+		if ($arg[0] == "list") {
+			list($number, $newUnit) = $arg[2];
+			return array("number", $this->assertNumber($number),
+				$this->compileValue($this->lib_e($newUnit)));
+		} else {
+			return array("number", $this->assertNumber($arg), "");
+		}
+	}
+
+	/**
+	 * Helper function to get arguments for color manipulation functions.
+	 * takes a list that contains a color like thing and a percentage
+	 */
+	public function colorArgs($args) {
+		if ($args[0] != 'list' || count($args[2]) < 2) {
+			return array(array('color', 0, 0, 0), 0);
+		}
+		list($color, $delta) = $args[2];
+		$color = $this->assertColor($color);
+		$delta = floatval($delta[1]);
+
+		return array($color, $delta);
+	}
+
+	protected function lib_darken($args) {
+		list($color, $delta) = $this->colorArgs($args);
+
+		$hsl = $this->toHSL($color);
+		$hsl[3] = $this->clamp($hsl[3] - $delta, 100);
+		return $this->toRGB($hsl);
+	}
+
+	protected function lib_lighten($args) {
+		list($color, $delta) = $this->colorArgs($args);
+
+		$hsl = $this->toHSL($color);
+		$hsl[3] = $this->clamp($hsl[3] + $delta, 100);
+		return $this->toRGB($hsl);
+	}
+
+	protected function lib_saturate($args) {
+		list($color, $delta) = $this->colorArgs($args);
+
+		$hsl = $this->toHSL($color);
+		$hsl[2] = $this->clamp($hsl[2] + $delta, 100);
+		return $this->toRGB($hsl);
+	}
+
+	protected function lib_desaturate($args) {
+		list($color, $delta) = $this->colorArgs($args);
+
+		$hsl = $this->toHSL($color);
+		$hsl[2] = $this->clamp($hsl[2] - $delta, 100);
+		return $this->toRGB($hsl);
+	}
+
+	protected function lib_spin($args) {
+		list($color, $delta) = $this->colorArgs($args);
+
+		$hsl = $this->toHSL($color);
+
+		$hsl[1] = $hsl[1] + $delta % 360;
+		if ($hsl[1] < 0) $hsl[1] += 360;
+
+		return $this->toRGB($hsl);
+	}
+
+	protected function lib_fadeout($args) {
+		list($color, $delta) = $this->colorArgs($args);
+		$color[4] = $this->clamp((isset($color[4]) ? $color[4] : 1) - $delta/100);
+		return $color;
+	}
+
+	protected function lib_fadein($args) {
+		list($color, $delta) = $this->colorArgs($args);
+		$color[4] = $this->clamp((isset($color[4]) ? $color[4] : 1) + $delta/100);
+		return $color;
+	}
+
+	protected function lib_hue($color) {
+		$hsl = $this->toHSL($this->assertColor($color));
+		return round($hsl[1]);
+	}
+
+	protected function lib_saturation($color) {
+		$hsl = $this->toHSL($this->assertColor($color));
+		return round($hsl[2]);
+	}
+
+	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
+	protected function lib_alpha($value) {
+		if (!is_null($color = $this->coerceColor($value))) {
+			return isset($color[4]) ? $color[4] : 1;
+		}
+	}
+
+	// set the alpha of the color
+	protected function lib_fade($args) {
+		list($color, $alpha) = $this->colorArgs($args);
+		$color[4] = $this->clamp($alpha / 100.0);
+		return $color;
+	}
+
+	protected function lib_percentage($arg) {
+		$num = $this->assertNumber($arg);
+		return array("number", $num*100, "%");
+	}
+
+	// mixes two colors by weight
+	// mix(@color1, @color2, [@weight: 50%]);
+	// http://sass-lang.com/docs/yardoc/Sass/Script/Functions.html#mix-instance_method
+	protected function lib_mix($args) {
+		if ($args[0] != "list" || count($args[2]) < 2)
+			$this->throwError("mix expects (color1, color2, weight)");
+
+		list($first, $second) = $args[2];
+		$first = $this->assertColor($first);
+		$second = $this->assertColor($second);
+
+		$first_a = $this->lib_alpha($first);
+		$second_a = $this->lib_alpha($second);
+
+		if (isset($args[2][2])) {
+			$weight = $args[2][2][1] / 100.0;
+		} else {
+			$weight = 0.5;
+		}
+
+		$w = $weight * 2 - 1;
+		$a = $first_a - $second_a;
+
+		$w1 = (($w * $a == -1 ? $w : ($w + $a)/(1 + $w * $a)) + 1) / 2.0;
+		$w2 = 1.0 - $w1;
+
+		$new = array('color',
+			$w1 * $first[1] + $w2 * $second[1],
+			$w1 * $first[2] + $w2 * $second[2],
+			$w1 * $first[3] + $w2 * $second[3],
+		);
+
+		if ($first_a != 1.0 || $second_a != 1.0) {
+			$new[] = $first_a * $weight + $second_a * ($weight - 1);
+		}
+
+		return $this->fixColor($new);
+	}
+
+	protected function lib_contrast($args) {
+	    $darkColor  = array('color', 0, 0, 0);
+	    $lightColor = array('color', 255, 255, 255);
+	    $threshold  = 0.43;
+
+	    if ( $args[0] == 'list' ) {
+	        $inputColor = ( isset($args[2][0]) ) ? $this->assertColor($args[2][0])  : $lightColor;
+	        $darkColor  = ( isset($args[2][1]) ) ? $this->assertColor($args[2][1])  : $darkColor;
+	        $lightColor = ( isset($args[2][2]) ) ? $this->assertColor($args[2][2])  : $lightColor;
+	        $threshold  = ( isset($args[2][3]) ) ? $this->assertNumber($args[2][3]) : $threshold;
+	    }
+	    else {
+	        $inputColor  = $this->assertColor($args);
+	    }
+
+	    $inputColor = $this->coerceColor($inputColor);
+	    $darkColor  = $this->coerceColor($darkColor);
+	    $lightColor = $this->coerceColor($lightColor);
+
+	    //Figure out which is actually light and dark!
+	    if ( $this->lib_luma($darkColor) > $this->lib_luma($lightColor) ) {
+	        $t  = $lightColor;
+	        $lightColor = $darkColor;
+	        $darkColor  = $t;
+	    }
+
+	    $inputColor_alpha = $this->lib_alpha($inputColor);
+	    if ( ( $this->lib_luma($inputColor) * $inputColor_alpha) < $threshold) {
+	        return $lightColor;
+	    }
+	    return $darkColor;
+	}
+
+	protected function lib_luma($color) {
+	    $color = $this->coerceColor($color);
+	    return (0.2126 * $color[0] / 255) + (0.7152 * $color[1] / 255) + (0.0722 * $color[2] / 255);
+	}
+
+
+	public function assertColor($value, $error = "expected color value") {
+		$color = $this->coerceColor($value);
+		if (is_null($color)) $this->throwError($error);
+		return $color;
+	}
+
+	public function assertNumber($value, $error = "expecting number") {
+		if ($value[0] == "number") return $value[1];
+		$this->throwError($error);
+	}
+
+	public function assertArgs($value, $expectedArgs, $name="") {
+		if ($expectedArgs == 1) {
+			return $value;
+		} else {
+			if ($value[0] !== "list" || $value[1] != ",") $this->throwError("expecting list");
+			$values = $value[2];
+			$numValues = count($values);
+			if ($expectedArgs != $numValues) {
+				if ($name) {
+					$name = $name . ": ";
+				}
+
+				$this->throwError("${name}expecting $expectedArgs arguments, got $numValues");
+			}
+
+			return $values;
+		}
+	}
+
+	protected function toHSL($color) {
+		if ($color[0] == 'hsl') return $color;
+
+		$r = $color[1] / 255;
+		$g = $color[2] / 255;
+		$b = $color[3] / 255;
+
+		$min = min($r, $g, $b);
+		$max = max($r, $g, $b);
+
+		$L = ($min + $max) / 2;
+		if ($min == $max) {
+			$S = $H = 0;
+		} else {
+			if ($L < 0.5)
+				$S = ($max - $min)/($max + $min);
+			else
+				$S = ($max - $min)/(2.0 - $max - $min);
+
+			if ($r == $max) $H = ($g - $b)/($max - $min);
+			elseif ($g == $max) $H = 2.0 + ($b - $r)/($max - $min);
+			elseif ($b == $max) $H = 4.0 + ($r - $g)/($max - $min);
+
+		}
+
+		$out = array('hsl',
+			($H < 0 ? $H + 6 : $H)*60,
+			$S*100,
+			$L*100,
+		);
+
+		if (count($color) > 4) $out[] = $color[4]; // copy alpha
+		return $out;
+	}
+
+	protected function toRGB_helper($comp, $temp1, $temp2) {
+		if ($comp < 0) $comp += 1.0;
+		elseif ($comp > 1) $comp -= 1.0;
+
+		if (6 * $comp < 1) return $temp1 + ($temp2 - $temp1) * 6 * $comp;
+		if (2 * $comp < 1) return $temp2;
+		if (3 * $comp < 2) return $temp1 + ($temp2 - $temp1)*((2/3) - $comp) * 6;
+
+		return $temp1;
+	}
+
+	/**
+	 * Converts a hsl array into a color value in rgb.
+	 * Expects H to be in range of 0 to 360, S and L in 0 to 100
+	 */
+	protected function toRGB($color) {
+		if ($color[0] == 'color') return $color;
+
+		$H = $color[1] / 360;
+		$S = $color[2] / 100;
+		$L = $color[3] / 100;
+
+		if ($S == 0) {
+			$r = $g = $b = $L;
+		} else {
+			$temp2 = $L < 0.5 ?
+				$L*(1.0 + $S) :
+				$L + $S - $L * $S;
+
+			$temp1 = 2.0 * $L - $temp2;
+
+			$r = $this->toRGB_helper($H + 1/3, $temp1, $temp2);
+			$g = $this->toRGB_helper($H, $temp1, $temp2);
+			$b = $this->toRGB_helper($H - 1/3, $temp1, $temp2);
+		}
+
+		// $out = array('color', round($r*255), round($g*255), round($b*255));
+		$out = array('color', $r*255, $g*255, $b*255);
+		if (count($color) > 4) $out[] = $color[4]; // copy alpha
+		return $out;
+	}
+
+	protected function clamp($v, $max = 1, $min = 0) {
+		return min($max, max($min, $v));
+	}
+
+	/**
+	 * Convert the rgb, rgba, hsl color literals of function type
+	 * as returned by the parser into values of color type.
+	 */
+	protected function funcToColor($func) {
+		$fname = $func[1];
+		if ($func[2][0] != 'list') return false; // need a list of arguments
+		$rawComponents = $func[2][2];
+
+		if ($fname == 'hsl' || $fname == 'hsla') {
+			$hsl = array('hsl');
+			$i = 0;
+			foreach ($rawComponents as $c) {
+				$val = $this->reduce($c);
+				$val = isset($val[1]) ? floatval($val[1]) : 0;
+
+				if ($i == 0) $clamp = 360;
+				elseif ($i < 3) $clamp = 100;
+				else $clamp = 1;
+
+				$hsl[] = $this->clamp($val, $clamp);
+				$i++;
+			}
+
+			while (count($hsl) < 4) $hsl[] = 0;
+			return $this->toRGB($hsl);
+
+		} elseif ($fname == 'rgb' || $fname == 'rgba') {
+			$components = array();
+			$i = 1;
+			foreach	($rawComponents as $c) {
+				$c = $this->reduce($c);
+				if ($i < 4) {
+					if ($c[0] == "number" && $c[2] == "%") {
+						$components[] = 255 * ($c[1] / 100);
+					} else {
+						$components[] = floatval($c[1]);
+					}
+				} elseif ($i == 4) {
+					if ($c[0] == "number" && $c[2] == "%") {
+						$components[] = 1.0 * ($c[1] / 100);
+					} else {
+						$components[] = floatval($c[1]);
+					}
+				} else break;
+
+				$i++;
+			}
+			while (count($components) < 3) $components[] = 0;
+			array_unshift($components, 'color');
+			return $this->fixColor($components);
+		}
+
+		return false;
+	}
+
+	protected function reduce($value, $forExpression = false) {
+		switch ($value[0]) {
+		case "interpolate":
+			$reduced = $this->reduce($value[1]);
+			$var = $this->compileValue($reduced);
+			$res = $this->reduce(array("variable", $this->vPrefix . $var));
+
+			if ($res[0] == "raw_color") {
+				$res = $this->coerceColor($res);
+			}
+
+			if (empty($value[2])) $res = $this->lib_e($res);
+
+			return $res;
+		case "variable":
+			$key = $value[1];
+			if (is_array($key)) {
+				$key = $this->reduce($key);
+				$key = $this->vPrefix . $this->compileValue($this->lib_e($key));
+			}
+
+			$seen =& $this->env->seenNames;
+
+			if (!empty($seen[$key])) {
+				$this->throwError("infinite loop detected: $key");
+			}
+
+			$seen[$key] = true;
+			$out = $this->reduce($this->get($key));
+			$seen[$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_'.str_replace('-', '_', $name));
+
+			if (is_callable($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, $exp));
+		}
+
+		if ($forExpression) {
+			switch ($value[0]) {
+			case "keyword":
+				if ($color = $this->coerceColor($value)) {
+					return $color;
+				}
+				break;
+			case "raw_color":
+				return $this->coerceColor($value);
+			}
+		}
+
+		return $value;
+	}
+
+
+	// coerce a value for use in color operation
+	protected function coerceColor($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])) {
+					$rgba = explode(',', self::$cssColors[$name]);
+
+					if(isset($rgba[3]))
+						return array('color', $rgba[0], $rgba[1], $rgba[2], $rgba[3]);
+
+					return array('color', $rgba[0], $rgba[1], $rgba[2]);
+				}
+				return null;
+		}
+	}
+
+	// make something string like into a string
+	protected function coerceString($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 $value;
+	}
+
+	public function toBool($a) {
+		if ($a) return self::$TRUE;
+		else return self::$FALSE;
+	}
+
+	// evaluate an expression
+	protected function evaluate($exp) {
+		list(, $op, $left, $right, $whiteBefore, $whiteAfter) = $exp;
+
+		$left = $this->reduce($left, true);
+		$right = $this->reduce($right, true);
+
+		if ($leftColor = $this->coerceColor($left)) {
+			$left = $leftColor;
+		}
+
+		if ($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);
+		}
+
+		if ($op == "=") {
+			return $this->toBool($this->eq($left, $right) );
+		}
+
+		if ($op == "+" && !is_null($str = $this->stringConcatenate($left, $right))) {
+			return $str;
+		}
+
+		// 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;
+		}
+
+		// make the expression look it did before being parsed
+		$paddedOp = $op;
+		if ($whiteBefore) $paddedOp = " " . $paddedOp;
+		if ($whiteAfter) $paddedOp .= " ";
+
+		return array("string", "", array($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 $strRight;
+		}
+	}
+
+
+	// make sure a color's components don't go out of bounds
+	protected function fixColor($c) {
+		foreach (range(1, 3) as $i) {
+			if ($c[$i] < 0) $c[$i] = 0;
+			if ($c[$i] > 255) $c[$i] = 255;
+		}
+
+		return $c;
+	}
+
+	protected function op_number_color($op, $lft, $rgt) {
+		if ($op == '+' || $op == '*') {
+			return $this->op_color_number($op, $rgt, $lft);
+		}
+	}
+
+	protected function op_color_number($op, $lft, $rgt) {
+		if ($rgt[0] == '%') $rgt[1] /= 100;
+
+		return $this->op_color_color($op, $lft,
+			array_fill(1, count($lft) - 1, $rgt[1]));
+	}
+
+	protected function op_color_color($op, $left, $right) {
+		$out = array('color');
+		$max = count($left) > count($right) ? count($left) : count($right);
+		foreach (range(1, $max - 1) as $i) {
+			$lval = isset($left[$i]) ? $left[$i] : 0;
+			$rval = isset($right[$i]) ? $right[$i] : 0;
+			switch ($op) {
+			case '+':
+				$out[] = $lval + $rval;
+				break;
+			case '-':
+				$out[] = $lval - $rval;
+				break;
+			case '*':
+				$out[] = $lval * $rval;
+				break;
+			case '%':
+				$out[] = $lval % $rval;
+				break;
+			case '/':
+				if ($rval == 0) $this->throwError("evaluate error: can't divide by zero");
+				$out[] = $lval / $rval;
+				break;
+			default:
+				$this->throwError('evaluate error: color op number failed on op '.$op);
+			}
+		}
+		return $this->fixColor($out);
+	}
+
+	function lib_red($color){
+		$color = $this->coerceColor($color);
+		if (is_null($color)) {
+			$this->throwError('color expected for red()');
+		}
+
+		return $color[1];
+	}
+
+	function lib_green($color){
+		$color = $this->coerceColor($color);
+		if (is_null($color)) {
+			$this->throwError('color expected for green()');
+		}
+
+		return $color[2];
+	}
+
+	function lib_blue($color){
+		$color = $this->coerceColor($color);
+		if (is_null($color)) {
+			$this->throwError('color expected for blue()');
+		}
+
+		return $color[3];
+	}
+
+
+	// operator on two numbers
+	protected function op_number_number($op, $left, $right) {
+		$unit = empty($left[2]) ? $right[2] : $left[2];
+
+		$value = 0;
+		switch ($op) {
+		case '+':
+			$value = $left[1] + $right[1];
+			break;
+		case '*':
+			$value = $left[1] * $right[1];
+			break;
+		case '-':
+			$value = $left[1] - $right[1];
+			break;
+		case '%':
+			$value = $left[1] % $right[1];
+			break;
+		case '/':
+			if ($right[1] == 0) $this->throwError('parse error: divide by zero');
+			$value = $left[1] / $right[1];
+			break;
+		case '<':
+			return $this->toBool($left[1] < $right[1]);
+		case '>':
+			return $this->toBool($left[1] > $right[1]);
+		case '>=':
+			return $this->toBool($left[1] >= $right[1]);
+		case '=<':
+			return $this->toBool($left[1] <= $right[1]);
+		default:
+			$this->throwError('parse error: unknown number operator: '.$op);
+		}
+
+		return array("number", $value, $unit);
+	}
+
+
+	/* environment functions */
+
+	protected function makeOutputBlock($type, $selectors = null) {
+		$b = new stdclass;
+		$b->lines = array();
+		$b->children = array();
+		$b->selectors = $selectors;
+		$b->type = $type;
+		$b->parent = $this->scope;
+		return $b;
+	}
+
+	// the state of execution
+	protected function pushEnv($block = null) {
+		$e = new stdclass;
+		$e->parent = $this->env;
+		$e->store = array();
+		$e->block = $block;
+
+		$this->env = $e;
+		return $e;
+	}
+
+	// pop something off the stack
+	protected function popEnv() {
+		$old = $this->env;
+		$this->env = $this->env->parent;
+		return $old;
+	}
+
+	// set something in the current env
+	protected function set($name, $value) {
+		$this->env->store[$name] = $value;
+	}
+
+
+	// get the highest occurrence entry for a name
+	protected function get($name) {
+		$current = $this->env;
+
+		$isArguments = $name == $this->vPrefix . 'arguments';
+		while ($current) {
+			if ($isArguments && isset($current->arguments)) {
+				return array('list', ' ', $current->arguments);
+			}
+
+			if (isset($current->store[$name]))
+				return $current->store[$name];
+			else {
+				$current = isset($current->storeParent) ?
+					$current->storeParent : $current->parent;
+			}
+		}
+
+		$this->throwError("variable $name is undefined");
+	}
+
+	// inject array of unparsed strings into environment as variables
+	protected function injectVariables($args) {
+		$this->pushEnv();
+		$parser = new lessc_parser($this, __METHOD__);
+		foreach ($args as $name => $strValue) {
+			if ($name{0} != '@') $name = '@'.$name;
+			$parser->count = 0;
+			$parser->buffer = (string)$strValue;
+			if (!$parser->propertyValue($value)) {
+				throw new Exception("failed to parse passed in variable $name: $strValue");
+			}
+
+			$this->set($name, $value);
+		}
+	}
+
+	/**
+	 * 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");
+
+		$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 $out;
+	}
+
+	public function compileFile($fname, $outFname = null) {
+		if (!is_readable($fname)) {
+			throw new Exception('load error: failed to find '.$fname);
+		}
+
+		$pi = pathinfo($fname);
+
+		$oldImport = $this->importDir;
+
+		$this->importDir = (array)$this->importDir;
+		$this->importDir[] = $pi['dirname'].'/';
+
+		$this->addParsedFile($fname);
+
+		$out = $this->compile(file_get_contents($fname), $fname);
+
+		$this->importDir = $oldImport;
+
+		if ($outFname !== null) {
+			return file_put_contents($outFname, $out);
+		}
+
+		return $out;
+	}
+
+	// compile only if changed input has changed or output doesn't exist
+	public function checkedCompile($in, $out) {
+		if (!is_file($out) || filemtime($in) > filemtime($out)) {
+			$this->compileFile($in, $out);
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Execute lessphp on a .less file or a lessphp cache structure
+	 *
+	 * The lessphp cache structure contains information about a specific
+	 * less file having been parsed. It can be used as a hint for future
+	 * calls to determine whether or not a rebuild is required.
+	 *
+	 * The cache structure contains two important keys that may be used
+	 * externally:
+	 *
+	 * compiled: The final compiled CSS
+	 * updated: The time (in seconds) the CSS was last compiled
+	 *
+	 * The cache structure is a plain-ol' PHP associative array and can
+	 * be serialized and unserialized without a hitch.
+	 *
+	 * @param mixed $in Input
+	 * @param bool $force Force rebuild?
+	 * @return array lessphp cache structure
+	 */
+	public function cachedCompile($in, $force = false) {
+		// assume no root
+		$root = null;
+
+		if (is_string($in)) {
+			$root = $in;
+		} elseif (is_array($in) and isset($in['root'])) {
+			if ($force or ! isset($in['files'])) {
+				// If we are forcing a recompile or if for some reason the
+				// structure does not contain any file information we should
+				// specify the root to trigger a rebuild.
+				$root = $in['root'];
+			} elseif (isset($in['files']) and is_array($in['files'])) {
+				foreach ($in['files'] as $fname => $ftime ) {
+					if (!file_exists($fname) or filemtime($fname) > $ftime) {
+						// One of the files we knew about previously has changed
+						// so we should look at our incoming root again.
+						$root = $in['root'];
+						break;
+					}
+				}
+			}
+		} else {
+			// TODO: Throw an exception? We got neither a string nor something
+			// that looks like a compatible lessphp cache structure.
+			return null;
+		}
+
+		if ($root !== null) {
+			// If we have a root value which means we should rebuild.
+			$out = array();
+			$out['root'] = $root;
+			$out['compiled'] = $this->compileFile($root);
+			$out['files'] = $this->allParsedFiles();
+			$out['updated'] = time();
+			return $out;
+		} else {
+			// No changes, pass back the structure
+			// we were given initially.
+			return $in;
+		}
+
+	}
+
+	// parse and compile buffer
+	// This is deprecated
+	public function parse($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 $this->allParsedFiles;
+	}
+
+	public function addParsedFile($file) {
+		$this->allParsedFiles[realpath($file)] = filemtime($file);
+	}
+
+	/**
+	 * Uses the current value of $this->count to show line and line number
+	 */
+	public function throwError($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',
+		'aqua' => '0,255,255',
+		'aquamarine' => '127,255,212',
+		'azure' => '240,255,255',
+		'beige' => '245,245,220',
+		'bisque' => '255,228,196',
+		'black' => '0,0,0',
+		'blanchedalmond' => '255,235,205',
+		'blue' => '0,0,255',
+		'blueviolet' => '138,43,226',
+		'brown' => '165,42,42',
+		'burlywood' => '222,184,135',
+		'cadetblue' => '95,158,160',
+		'chartreuse' => '127,255,0',
+		'chocolate' => '210,105,30',
+		'coral' => '255,127,80',
+		'cornflowerblue' => '100,149,237',
+		'cornsilk' => '255,248,220',
+		'crimson' => '220,20,60',
+		'cyan' => '0,255,255',
+		'darkblue' => '0,0,139',
+		'darkcyan' => '0,139,139',
+		'darkgoldenrod' => '184,134,11',
+		'darkgray' => '169,169,169',
+		'darkgreen' => '0,100,0',
+		'darkgrey' => '169,169,169',
+		'darkkhaki' => '189,183,107',
+		'darkmagenta' => '139,0,139',
+		'darkolivegreen' => '85,107,47',
+		'darkorange' => '255,140,0',
+		'darkorchid' => '153,50,204',
+		'darkred' => '139,0,0',
+		'darksalmon' => '233,150,122',
+		'darkseagreen' => '143,188,143',
+		'darkslateblue' => '72,61,139',
+		'darkslategray' => '47,79,79',
+		'darkslategrey' => '47,79,79',
+		'darkturquoise' => '0,206,209',
+		'darkviolet' => '148,0,211',
+		'deeppink' => '255,20,147',
+		'deepskyblue' => '0,191,255',
+		'dimgray' => '105,105,105',
+		'dimgrey' => '105,105,105',
+		'dodgerblue' => '30,144,255',
+		'firebrick' => '178,34,34',
+		'floralwhite' => '255,250,240',
+		'forestgreen' => '34,139,34',
+		'fuchsia' => '255,0,255',
+		'gainsboro' => '220,220,220',
+		'ghostwhite' => '248,248,255',
+		'gold' => '255,215,0',
+		'goldenrod' => '218,165,32',
+		'gray' => '128,128,128',
+		'green' => '0,128,0',
+		'greenyellow' => '173,255,47',
+		'grey' => '128,128,128',
+		'honeydew' => '240,255,240',
+		'hotpink' => '255,105,180',
+		'indianred' => '205,92,92',
+		'indigo' => '75,0,130',
+		'ivory' => '255,255,240',
+		'khaki' => '240,230,140',
+		'lavender' => '230,230,250',
+		'lavenderblush' => '255,240,245',
+		'lawngreen' => '124,252,0',
+		'lemonchiffon' => '255,250,205',
+		'lightblue' => '173,216,230',
+		'lightcoral' => '240,128,128',
+		'lightcyan' => '224,255,255',
+		'lightgoldenrodyellow' => '250,250,210',
+		'lightgray' => '211,211,211',
+		'lightgreen' => '144,238,144',
+		'lightgrey' => '211,211,211',
+		'lightpink' => '255,182,193',
+		'lightsalmon' => '255,160,122',
+		'lightseagreen' => '32,178,170',
+		'lightskyblue' => '135,206,250',
+		'lightslategray' => '119,136,153',
+		'lightslategrey' => '119,136,153',
+		'lightsteelblue' => '176,196,222',
+		'lightyellow' => '255,255,224',
+		'lime' => '0,255,0',
+		'limegreen' => '50,205,50',
+		'linen' => '250,240,230',
+		'magenta' => '255,0,255',
+		'maroon' => '128,0,0',
+		'mediumaquamarine' => '102,205,170',
+		'mediumblue' => '0,0,205',
+		'mediumorchid' => '186,85,211',
+		'mediumpurple' => '147,112,219',
+		'mediumseagreen' => '60,179,113',
+		'mediumslateblue' => '123,104,238',
+		'mediumspringgreen' => '0,250,154',
+		'mediumturquoise' => '72,209,204',
+		'mediumvioletred' => '199,21,133',
+		'midnightblue' => '25,25,112',
+		'mintcream' => '245,255,250',
+		'mistyrose' => '255,228,225',
+		'moccasin' => '255,228,181',
+		'navajowhite' => '255,222,173',
+		'navy' => '0,0,128',
+		'oldlace' => '253,245,230',
+		'olive' => '128,128,0',
+		'olivedrab' => '107,142,35',
+		'orange' => '255,165,0',
+		'orangered' => '255,69,0',
+		'orchid' => '218,112,214',
+		'palegoldenrod' => '238,232,170',
+		'palegreen' => '152,251,152',
+		'paleturquoise' => '175,238,238',
+		'palevioletred' => '219,112,147',
+		'papayawhip' => '255,239,213',
+		'peachpuff' => '255,218,185',
+		'peru' => '205,133,63',
+		'pink' => '255,192,203',
+		'plum' => '221,160,221',
+		'powderblue' => '176,224,230',
+		'purple' => '128,0,128',
+		'red' => '255,0,0',
+		'rosybrown' => '188,143,143',
+		'royalblue' => '65,105,225',
+		'saddlebrown' => '139,69,19',
+		'salmon' => '250,128,114',
+		'sandybrown' => '244,164,96',
+		'seagreen' => '46,139,87',
+		'seashell' => '255,245,238',
+		'sienna' => '160,82,45',
+		'silver' => '192,192,192',
+		'skyblue' => '135,206,235',
+		'slateblue' => '106,90,205',
+		'slategray' => '112,128,144',
+		'slategrey' => '112,128,144',
+		'snow' => '255,250,250',
+		'springgreen' => '0,255,127',
+		'steelblue' => '70,130,180',
+		'tan' => '210,180,140',
+		'teal' => '0,128,128',
+		'thistle' => '216,191,216',
+		'tomato' => '255,99,71',
+		'transparent' => '0,0,0,0',
+		'turquoise' => '64,224,208',
+		'violet' => '238,130,238',
+		'wheat' => '245,222,179',
+		'white' => '255,255,255',
+		'whitesmoke' => '245,245,245',
+		'yellow' => '255,255,0',
+		'yellowgreen' => '154,205,50'
+	);
+}
+
+// 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", "viewport", "-moz-viewport", "-o-viewport", "-ms-viewport");
+	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
+		while (false !== $this->parseChunk());
+
+		if ($this->count != strlen($this->buffer))
+			$this->throwError();
+
+		// TODO report where the block was opened
+		if ( !property_exists($this->env, 'parent') || !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 = $this->seek();
+
+		if ($this->whitespace()) {
+			return true;
+		}
+
+		// 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('{', false)) {
+			$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->argumentDef($argv, $isVararg) || true) &&
+			($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(&$out) {
+		if (!$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[] = $value;
+			return true;
+		} elseif ($this->variable($variable)) {
+			$out = array('variable', $variable);
+			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[] = $inter;
+				continue;
+			}
+
+			if (!empty($rejectStrs) && in_array($tok, $rejectStrs)) {
+				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->openString("}", $interp, null, array("'", '"', ";")) &&
+			$this->literal("}", false))
+		{
+			$out = array("interpolate", $interp);
+			$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", $m[1]);
+			}
+			return true;
+		}
+
+		return false;
+	}
+
+	// consume an argument definition list surrounded by ()
+	// each argument is a variable name with optional value
+	// or at the end a ... or a variable named followed by ...
+	// arguments are separated by , unless a ; is in the list, then ; is the
+	// delimiter.
+	protected function argumentDef(&$args, &$isVararg) {
+		$s = $this->seek();
+		if (!$this->literal('(')) return false;
+
+		$values = array();
+		$delim = ",";
+		$method = "expressionList";
+
+		$isVararg = false;
+		while (true) {
+			if ($this->literal("...")) {
+				$isVararg = true;
+				break;
+			}
+
+			if ($this->$method($value)) {
+				if ($value[0] == "variable") {
+					$arg = array("arg", $value[1]);
+					$ss = $this->seek();
+
+					if ($this->assign() && $this->$method($rhs)) {
+						$arg[] = $rhs;
+					} else {
+						$this->seek($ss);
+						if ($this->literal("...")) {
+							$arg[0] = "rest";
+							$isVararg = true;
+						}
+					}
+
+					$values[] = $arg;
+					if ($isVararg) break;
+					continue;
+				} else {
+					$values[] = array("lit", $value);
+				}
+			}
+
+
+			if (!$this->literal($delim)) {
+				if ($delim == "," && $this->literal(";")) {
+					// found new delim, convert existing args
+					$delim = ";";
+					$method = "propertyValue";
+
+					// transform arg list
+					if (isset($values[1])) { // 2 items
+						$newList = array();
+						foreach ($values as $i => $arg) {
+							switch($arg[0]) {
+							case "arg":
+								if ($i) {
+									$this->throwError("Cannot mix ; and , as delimiter types");
+								}
+								$newList[] = $arg[2];
+								break;
+							case "lit":
+								$newList[] = $arg[1];
+								break;
+							case "rest":
+								$this->throwError("Unexpected rest before semicolon");
+							}
+						}
+
+						$newList = array("list", ", ", $newList);
+
+						switch ($values[0][0]) {
+						case "arg":
+							$newArg = array("arg", $values[0][1], $newList);
+							break;
+						case "lit":
+							$newArg = array("lit", $newList);
+							break;
+						}
+
+					} elseif ($values) { // 1 item
+						$newArg = $values[0];
+					}
+
+					if ($newArg) {
+						$values = array($newArg);
+					}
+				} else {
+					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) {
+		$tags = array();
+		while ($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(&$parts, &$hasExpression) {
+		// speed shortcut
+		if (isset($this->buffer[$this->count]) && $this->buffer[$this->count] != "[") {
+			return false;
+		}
+
+		$s = $this->seek();
+
+		$hasInterpolation = false;
+
+		if ($this->literal("[", false)) {
+			$attrParts = array("[");
+			// keyword, string, operator
+			while (true) {
+				if ($this->literal("]", false)) {
+					$this->count--;
+					break; // get out early
+				}
+
+				if ($this->match('\s+', $m)) {
+					$attrParts[] = " ";
+					continue;
+				}
+				if ($this->string($str)) {
+					// escape parent selector, (yuck)
+					foreach ($str[2] as &$chunk) {
+						$chunk = str_replace($this->lessc->parentSelector, "$&$", $chunk);
+					}
+
+					$attrParts[] = $str;
+					$hasInterpolation = true;
+					continue;
+				}
+
+				if ($this->keyword($word)) {
+					$attrParts[] = $word;
+					continue;
+				}
+
+				if ($this->interpolation($inter, false)) {
+					$attrParts[] = $inter;
+					$hasInterpolation = true;
+					continue;
+				}
+
+				// operator, handles attr namespace too
+				if ($this->match('[|-~\$\*\^=]+', $m)) {
+					$attrParts[] = $m[0];
+					continue;
+				}
+
+				break;
+			}
+
+			if ($this->literal("]", false)) {
+				$attrParts[] = "]";
+				foreach ($attrParts as $part) {
+					$parts[] = $part;
+				}
+				$hasExpression = $hasExpression || $hasInterpolation;
+				return true;
+			}
+			$this->seek($s);
+		}
+
+		$this->seek($s);
+		return false;
+	}
+
+	// a space separated list of selectors
+	protected function tag(&$tag, $simple = false) {
+		if ($simple)
+			$chars = '^@,:;{}\][>\(\) "\'';
+		else
+			$chars = '^@,;{}["\'';
+
+		$s = $this->seek();
+
+		$hasExpression = false;
+		$parts = array();
+		while ($this->tagBracket($parts, $hasExpression));
+
+		$oldWhite = $this->eatWhiteDefault;
+		$this->eatWhiteDefault = false;
+
+		while (true) {
+			if ($this->match('(['.$chars.'0-9]['.$chars.']*)', $m)) {
+				$parts[] = $m[1];
+				if ($simple) break;
+
+				while ($this->tagBracket($parts, $hasExpression));
+				continue;
+			}
+
+			if (isset($this->buffer[$this->count]) && $this->buffer[$this->count] == "@") {
+				if ($this->interpolation($interp)) {
+					$hasExpression = true;
+					$interp[2] = true; // don't unescape
+					$parts[] = $interp;
+					continue;
+				}
+
+				if ($this->literal("@")) {
+					$parts[] = "@";
+					continue;
+				}
+			}
+
+			if ($this->unit($unit)) { // for keyframes
+				$parts[] = $unit[1];
+				$parts[] = $unit[2];
+				continue;
+			}
+
+			break;
+		}
+
+		$this->eatWhiteDefault = $oldWhite;
+		if (!$parts) {
+			$this->seek($s);
+			return false;
+		}
+
+		if ($hasExpression) {
+			$tag = array("exp", array("string", "", $parts));
+		} else {
+			$tag = trim(implode($parts));
+		}
+
+		$this->whitespace();
+		return true;
+	}
+
+	// a css function
+	protected function func(&$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(';', false)) {
+			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($this->seenComments[$this->count])) {
+					$this->append(array("comment", $m[1]));
+					$this->seenComments[$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 = ",";
+}
+
+