/wp-content/plugins/all-in-one-event-calendar/vendor/lessphp/lessc.inc.php

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<?php
/**
 * lessphp v0.4.0
 * http://leafo.net/lessphp
 *
 * LESS css compiler, adapted from http://lesscss.org
 *
 * Copyright 2012, Leaf Corcoran <leafot@gmail.com>
 * Licensed under MIT or GPLv3, see LICENSE
 */
if ( ! class_exists( 'lessc' ) ) {
	/**
	 * 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 intstance of the parser, feeds it LESS code,
	 * then transforms the resulting tree to a CSS tree. This class also holds the
	 * evaluation context, such as all available mixins and variables at any given
	 * time.
	 *
	 * The `lessc_parser` class is only concerned with parsing its input.
	 *
	 * The `lessc_formatter` takes a CSS tree, and dumps it to a formatted string,
	 * handling things like indentation.
	 */
	class lessc {
		static public $VERSION = "v0.4.0";
		static protected $TRUE = array("keyword", "true");
		static protected $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 public $defaultValue = array("keyword", "");

		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);
			}

			$out->lines = array_values(array_unique($out->lines));
		}

		protected function sortProps($props, $split = false) {
			$vars = array();
			$imports = array();
			$other = array();

			foreach ($props as $prop) {
				switch ($prop[0]) {
					case "assign":
						if (isset($prop[1][0]) && $prop[1][0] == $this->vPrefix) {
							$vars[] = $prop;
						} else {
							$other[] = $prop;
						}
						break;
					case "import":
						$id = self::$nextImportId++;
						$prop[] = $id;
						$imports[] = $prop;
						$other[] = array("import_mixin", $id);
						break;
					default:
						$other[] = $prop;
				}
			}

			if ($split) {
				return array(array_merge($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 = $a[2];
					} else {
						// ==============================
						// ========= TIMELY FIX =========
						// ==============================
						// lessphp is not yet compatible with Bootstrap >3.0.0, so for
						// compilation to succeed, this line must be commented:
						//$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) {
						// fwrite(STDERR,"failed to find block: ".implode(" > ", $path)."\n");
						break; // throw error here??
					}

					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.
		 */
		protected function compileValue($value) {
			switch ($value[0]) {
				case 'list':
					// [1] - delimiter
					// [2] - array of values
					return implode($value[1], array_map(array($this, 'compileValue'), $value[2]));
				case 'raw_color':
					if (!empty($this->formatter->compressColors)) {
						return $this->compileValue($this->coerceColor($value));
					}
					return $value[1];
				case 'keyword':
					// [1] - the keyword
					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);
		}

		// 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]);
					}
					return self::$defaultValue;
				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) {
			$value = $this->assertNumber($arg);
			return array("number", round($value), $arg[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
		 */
		protected 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($args) {
			if ($args[0] != 'list' || count($args[2]) < 3) {
				return array(array('color', 0, 0, 0), 0);
			}

			list($inputColor, $darkColor, $lightColor) = $args[2];

			$inputColor = $this->assertColor($inputColor);
			$darkColor = $this->assertColor($darkColor);
			$lightColor = $this->assertColor($lightColor);
			$hsl = $this->toHSL($inputColor);

			if ($hsl[3] > 50) {
				return $darkColor;
			}

			return $lightColor;
		}

		protected function assertColor($value, $error = "expected color value") {
			$color = $this->coerceColor($value);
			if (is_null($color)) $this->throwError($error);
			return $color;
		}

		protected function assertNumber($value, $error = "expecting number") {
			if ($value[0] == "number") return $value[1];
			$this->throwError($error);
		}

		protected 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($key, self::$defaultValue));
					$seen[$key] = false;
					return $out;
				case "list":
					foreach ($value[2] as &$item) {
						$item = $this->reduce($item, $forExpression);
					}
					return $value;
				case "expression":
					return $this->evaluate($value);
				case "string":
					foreach ($value[2] as &$part) {
						if (is_array($part)) {
							$strip = $part[0] == "variable";
							$part = $this->reduce($part);
							if ($strip) $part = $this->lib_e($part);
						}
					}
					return $value;
				case "escape":
					list(,$inner) = $value;
					return $this->lib_e($this->reduce($inner));
				case "function":
					$color = $this->funcToColor($value);
					if ($color) return $color;

					list(, $name, $args) = $value;
					if ($name == "%") $name = "_sprintf";
					$f = isset($this->libFunctions[$name]) ?
					$this->libFunctions[$name] : array($this, 'lib_'.$name);

					if (is_callable($f)) {
						if ($args[0] == 'list')
							$args = self::compressList($args[2], $args[1]);

						$ret = call_user_func($f, $this->reduce($args, true), $this);

						if (is_null($ret)) {
							return array("string", "", array(
								$name, "(", $args, ")"
							));
						}

						// convert to a typed value if the result is a php primitive
						if (is_numeric($ret)) $ret = array('number', $ret, "");
						elseif (!is_array($ret)) $ret = array('keyword', $ret);

						return $ret;
					}

					// plain function, reduce args
					$value[2] = $this->reduce($value[2]);
					return $value;
				case "unary":
					list(, $op, $exp) = $value;
					$exp = $this->reduce($exp);

					if ($exp[0] == "number") {
						switch ($op) {
							case "+":
								return $exp;
							case "-":
								$exp[1] *= -1;
								return $exp;
						}
					}
					return array("string", "", array($op, $exp));
			}

			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;
		}

		protected 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, $default=null) {
			$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;
				}
			}

			return $default;
		}

		// 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…