Subversion Repositories SmartDukaan

<?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
 */


/**
 * 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 ($split) {
                        return array(array_merge($vars, $imports), $other);
                } else {
                        return array_merge($vars, $imports, $other);
                }
        }

        protected function compileMediaQuery($queries) {
                $compiledQueries = array();
                foreach ($queries as $query) {
                        $parts = array();
                        foreach ($query as $q) {
                                switch ($q[0]) {
                                case "mediaType":
                                        $parts[] = implode(" ", array_slice($q, 1));
                                        break;
                                case "mediaExp":
                                        if (isset($q[2])) {
                                                $parts[] = "($q[1]: " .
                                                        $this->compileValue($this->reduce($q[2])) . ")";
                                        } else {
                                                $parts[] = "($q[1])";
                                        }
                                        break;
                                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) {
                                // 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 $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;
        }

        protected function addParsedFile($file) {
                $this->allParsedFiles[realpath($file)] = filemtime($file);
        }

        /**
         * Uses the current value of $this->count to show line and line number
         */
        protected function throwError($msg = null) {
                if ($this->sourceLoc >= 0) {
                        $this->sourceParser->throwError($msg, $this->sourceLoc);
                }
                throw new exception($msg);
        }

        // compile file $in to file $out if $in is newer than $out
        // returns true when it compiles, false otherwise
        public static function ccompile($in, $out, $less = null) {
                if ($less === null) {
                        $less = new self;
                }
                return $less->checkedCompile($in, $out);
        }

        public static function cexecute($in, $force = false, $less = null) {
                if ($less === null) {
                        $less = new self;
                }
                return $less->cachedCompile($in, $force);
        }

        static protected $cssColors = array(
                'aliceblue' => '240,248,255',
                'antiquewhite' => '250,235,215',
                '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
                $lastCount = $this->count;
                while (false !== $this->parseChunk());

                if ($this->count != strlen($this->buffer))
                        $this->throwError();

                // TODO report where the block was opened
                if (!is_null($this->env->parent))
                        throw new exception('parse error: unclosed block');

                return $this->env;
        }

        /**
         * Parse a single chunk off the head of the buffer and append it to the
         * current parse environment.
         * Returns false when the buffer is empty, or when there is an error.
         *
         * This function is called repeatedly until the entire document is
         * parsed.
         *
         * This parser is most similar to a recursive descent parser. Single
         * functions represent discrete grammatical rules for the language, and
         * they are able to capture the text that represents those rules.
         *
         * Consider the function lessc::keyword(). (all parse functions are
         * structured the same)
         *
         * The function takes a single reference argument. When calling the
         * function it will attempt to match a keyword on the head of the buffer.
         * If it is successful, it will place the keyword in the referenced
         * argument, advance the position in the buffer, and return true. If it
         * fails then it won't advance the buffer and it will return false.
         *
         * All of these parse functions are powered by lessc::match(), which behaves
         * the same way, but takes a literal regular expression. Sometimes it is
         * more convenient to use match instead of creating a new function.
         *
         * Because of the format of the functions, to parse an entire string of
         * grammatical rules, you can chain them together using &&.
         *
         * But, if some of the rules in the chain succeed before one fails, then
         * the buffer position will be left at an invalid state. In order to
         * avoid this, lessc::seek() is used to remember and set buffer positions.
         *
         * Before parsing a chain, use $s = $this->seek() to remember the current
         * position into $s. Then if a chain fails, use $this->seek($s) to
         * go back where we started.
         */
        protected function parseChunk() {
                if (empty($this->buffer)) return false;
                $s = $this->seek();

                // setting a property
                if ($this->keyword($key) && $this->assign() &&
                        $this->propertyValue($value, $key) && $this->end())
                {
                        $this->append(array('assign', $key, $value), $s);
                        return true;
                } else {
                        $this->seek($s);
                }


                // look for special css blocks
                if ($this->literal('@', false)) {
                        $this->count--;

                        // media
                        if ($this->literal('@media')) {
                                if (($this->mediaQueryList($mediaQueries) || true)
                                        && $this->literal('{'))
                                {
                                        $media = $this->pushSpecialBlock("media");
                                        $media->queries = is_null($mediaQueries) ? array() : $mediaQueries;
                                        return true;
                                } else {
                                        $this->seek($s);
                                        return false;
                                }
                        }

                        if ($this->literal("@", false) && $this->keyword($dirName)) {
                                if ($this->isDirective($dirName, $this->blockDirectives)) {
                                        if (($this->openString("{", $dirValue, null, array(";")) || true) &&
                                                $this->literal("{"))
                                        {
                                                $dir = $this->pushSpecialBlock("directive");
                                                $dir->name = $dirName;
                                                if (isset($dirValue)) $dir->value = $dirValue;
                                                return true;
                                        }
                                } elseif ($this->isDirective($dirName, $this->lineDirectives)) {
                                        if ($this->propertyValue($dirValue) && $this->end()) {
                                                $this->append(array("directive", $dirName, $dirValue));
                                                return true;
                                        }
                                }
                        }

                        $this->seek($s);
                }

                // setting a variable
                if ($this->variable($var) && $this->assign() &&
                        $this->propertyValue($value) && $this->end())
                {
                        $this->append(array('assign', $var, $value), $s);
                        return true;
                } else {
                        $this->seek($s);
                }

                if ($this->import($importValue)) {
                        $this->append($importValue, $s);
                        return true;
                }

                // opening parametric mixin
                if ($this->tag($tag, true) && $this->argumentDef($args, $isVararg) &&
                        ($this->guards($guards) || true) &&
                        $this->literal('{'))
                {
                        $block = $this->pushBlock($this->fixTags(array($tag)));
                        $block->args = $args;
                        $block->isVararg = $isVararg;
                        if (!empty($guards)) $block->guards = $guards;
                        return true;
                } else {
                        $this->seek($s);
                }

                // opening a simple block
                if ($this->tags($tags) && $this->literal('{')) {
                        $tags = $this->fixTags($tags);
                        $this->pushBlock($tags);
                        return true;
                } else {
                        $this->seek($s);
                }

                // closing a block
                if ($this->literal('}', false)) {
                        try {
                                $block = $this->pop();
                        } catch (exception $e) {
                                $this->seek($s);
                                $this->throwError($e->getMessage());
                        }

                        $hidden = false;
                        if (is_null($block->type)) {
                                $hidden = true;
                                if (!isset($block->args)) {
                                        foreach ($block->tags as $tag) {
                                                if (!is_string($tag) || $tag{0} != $this->lessc->mPrefix) {
                                                        $hidden = false;
                                                        break;
                                                }
                                        }
                                }

                                foreach ($block->tags as $tag) {
                                        if (is_string($tag)) {
                                                $this->env->children[$tag][] = $block;
                                        }
                                }
                        }

                        if (!$hidden) {
                                $this->append(array('block', $block), $s);
                        }

                        // this is done here so comments aren't bundled into he block that
                        // was just closed
                        $this->whitespace();
                        return true;
                }

                // mixin
                if ($this->mixinTags($tags) &&
                        ($this->argumentDef($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) {
                $s = $this->seek();
                if (!$this->literal('@import')) return false;

                // @import "something.css" media;
                // @import url("something.css") media;
                // @import url(something.css) media;

                if ($this->propertyValue($value)) {
                        $out = array("import", $value);
                        return true;
                }
        }

        protected function mediaQueryList(&$out) {
                if ($this->genericList($list, "mediaQuery", ",", false)) {
                        $out = $list[2];
                        return true;
                }
                return false;
        }

        protected function mediaQuery(&$out) {
                $s = $this->seek();

                $expressions = null;
                $parts = array();

                if (($this->literal("only") && ($only = true) || $this->literal("not") && ($not = true) || true) && $this->keyword($mediaType)) {
                        $prop = array("mediaType");
                        if (isset($only)) $prop[] = "only";
                        if (isset($not)) $prop[] = "not";
                        $prop[] = $mediaType;
                        $parts[] = $prop;
                } else {
                        $this->seek($s);
                }


                if (!empty($mediaType) && !$this->literal("and")) {
                        // ~
                } else {
                        $this->genericList($expressions, "mediaExpression", "and", false);
                        if (is_array($expressions)) $parts = array_merge($parts, $expressions[2]);
                }

                if (count($parts) == 0) {
                        $this->seek($s);
                        return false;
                }

                $out = $parts;
                return true;
        }

        protected function mediaExpression(&$out) {
                $s = $this->seek();
                $value = null;
                if ($this->literal("(") &&
                        $this->keyword($feature) &&
                        ($this->literal(":") && $this->expression($value) || true) &&
                        $this->literal(")"))
                {
                        $out = array("mediaExp", $feature);
                        if ($value) $out[] = $value;
                        return true;
                } elseif ($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) {
                $s = $this->seek();
                $tags = array();
                while ($this->tag($tt, true)) {
                        $tags[] = $tt;
                        $this->literal(">");
                }

                if (count($tags) == 0) return false;

                return true;
        }

        // a bracketed value (contained within in a tag definition)
        protected function tagBracket(&$parts, &$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 ($this->literal(';')) {
                        return true;
                } elseif ($this->count == strlen($this->buffer) || $this->buffer[$this->count] == '}') {
                        // if there is end of file or a closing block next then we don't need a ;
                        return true;
                }
                return false;
        }

        protected function guards(&$guards) {
                $s = $this->seek();

                if (!$this->literal("when")) {
                        $this->seek($s);
                        return false;
                }

                $guards = array();

                while ($this->guardGroup($g)) {
                        $guards[] = $g;
                        if (!$this->literal(",")) break;
                }

                if (count($guards) == 0) {
                        $guards = null;
                        $this->seek($s);
                        return false;
                }

                return true;
        }

        // a bunch of guards that are and'd together
        // TODO rename to guardGroup
        protected function guardGroup(&$guardGroup) {
                $s = $this->seek();
                $guardGroup = array();
                while ($this->guard($guard)) {
                        $guardGroup[] = $guard;
                        if (!$this->literal("and")) break;
                }

                if (count($guardGroup) == 0) {
                        $guardGroup = null;
                        $this->seek($s);
                        return false;
                }

                return true;
        }

        protected function guard(&$guard) {
                $s = $this->seek();
                $negate = $this->literal("not");

                if ($this->literal("(") && $this->expression($exp) && $this->literal(")")) {
                        $guard = $exp;
                        if ($negate) $guard = array("negate", $guard);
                        return true;
                }

                $this->seek($s);
                return false;
        }

        /* raw parsing functions */

        protected function literal($what, $eatWhitespace = null) {
                if ($eatWhitespace === null) $eatWhitespace = $this->eatWhiteDefault;

                // shortcut on single letter
                if (!isset($what[1]) && isset($this->buffer[$this->count])) {
                        if ($this->buffer[$this->count] == $what) {
                                if (!$eatWhitespace) {
                                        $this->count++;
                                        return true;
                                }
                                // goes below...
                        } else {
                                return false;
                        }
                }

                if (!isset(self::$literalCache[$what])) {
                        self::$literalCache[$what] = lessc::preg_quote($what);
                }

                return $this->match(self::$literalCache[$what], $m, $eatWhitespace);
        }

        protected function genericList(&$out, $parseItem, $delim="", $flatten=true) {
                $s = $this->seek();
                $items = array();
                while ($this->$parseItem($value)) {
                        $items[] = $value;
                        if ($delim) {
                                if (!$this->literal($delim)) break;
                        }
                }

                if (count($items) == 0) {
                        $this->seek($s);
                        return false;
                }

                if ($flatten && count($items) == 1) {
                        $out = $items[0];
                } else {
                        $out = array("list", $delim, $items);
                }

                return true;
        }


        // advance counter to next occurrence of $what
        // $until - don't include $what in advance
        // $allowNewline, if string, will be used as valid char set
        protected function to($what, &$out, $until = false, $allowNewline = false) {
                if (is_string($allowNewline)) {
                        $validChars = $allowNewline;
                } else {
                        $validChars = $allowNewline ? "." : "[^\n]";
                }
                if (!$this->match('('.$validChars.'*?)'.lessc::preg_quote($what), $m, !$until)) return false;
                if ($until) $this->count -= strlen($what); // give back $what
                $out = $m[1];
                return true;
        }

        // try to match something on head of buffer
        protected function match($regex, &$out, $eatWhitespace = null) {
                if ($eatWhitespace === null) $eatWhitespace = $this->eatWhiteDefault;

                $r = '/'.$regex.($eatWhitespace && !$this->writeComments ? '\s*' : '').'/Ais';
                if (preg_match($r, $this->buffer, $out, null, $this->count)) {
                        $this->count += strlen($out[0]);
                        if ($eatWhitespace && $this->writeComments) $this->whitespace();
                        return true;
                }
                return false;
        }

        // match some whitespace
        protected function whitespace() {
                if ($this->writeComments) {
                        $gotWhite = false;
                        while (preg_match(self::$whitePattern, $this->buffer, $m, null, $this->count)) {
                                if (isset($m[1]) && empty($this->commentsSeen[$this->count])) {
                                        $this->append(array("comment", $m[1]));
                                        $this->commentsSeen[$this->count] = true;
                                }
                                $this->count += strlen($m[0]);
                                $gotWhite = true;
                        }
                        return $gotWhite;
                } else {
                        $this->match("", $m);
                        return strlen($m[0]) > 0;
                }
        }

        // match something without consuming it
        protected function peek($regex, &$out = null, $from=null) {
                if (is_null($from)) $from = $this->count;
                $r = '/'.$regex.'/Ais';
                $result = preg_match($r, $this->buffer, $out, null, $from);

                return $result;
        }

        // seek to a spot in the buffer or return where we are on no argument
        protected function seek($where = null) {
                if ($where === null) return $this->count;
                else $this->count = $where;
                return true;
        }

        /* misc functions */

        public function throwError($msg = "parse error", $count = null) {
                $count = is_null($count) ? $this->count : $count;

                $line = $this->line +
                        substr_count(substr($this->buffer, 0, $count), "\n");

                if (!empty($this->sourceName)) {
                        $loc = "$this->sourceName on line $line";
                } else {
                        $loc = "line: $line";
                }

                // TODO this depends on $this->count
                if ($this->peek("(.*?)(\n|$)", $m, $count)) {
                        throw new exception("$msg: failed at `$m[1]` $loc");
                } else {
                        throw new exception("$msg: $loc");
                }
        }

        protected function pushBlock($selectors=null, $type=null) {
                $b = new stdclass;
                $b->parent = $this->env;

                $b->type = $type;
                $b->id = self::$nextBlockId++;

                $b->isVararg = false; // TODO: kill me from here
                $b->tags = $selectors;

                $b->props = array();
                $b->children = array();

                $this->env = $b;
                return $b;
        }

        // push a block that doesn't multiply tags
        protected function pushSpecialBlock($type) {
                return $this->pushBlock(null, $type);
        }

        // append a property to the current block
        protected function append($prop, $pos = null) {
                if ($pos !== null) $prop[-1] = $pos;
                $this->env->props[] = $prop;
        }

        // pop something off the stack
        protected function pop() {
                $old = $this->env;
                $this->env = $this->env->parent;
                return $old;
        }

        // remove comments from $text
        // todo: make it work for all functions, not just url
        protected function removeComments($text) {
                $look = array(
                        'url(', '//', '/*', '"', "'"
                );

                $out = '';
                $min = null;
                while (true) {
                        // find the next item
                        foreach ($look as $token) {
                                $pos = strpos($text, $token);
                                if ($pos !== false) {
                                        if (!isset($min) || $pos < $min[1]) $min = array($token, $pos);
                                }
                        }

                        if (is_null($min)) break;

                        $count = $min[1];
                        $skip = 0;
                        $newlines = 0;
                        switch ($min[0]) {
                        case 'url(':
                                if (preg_match('/url\(.*?\)/', $text, $m, 0, $count))
                                        $count += strlen($m[0]) - strlen($min[0]);
                                break;
                        case '"':
                        case "'":
                                if (preg_match('/'.$min[0].'.*?(?<!\\\\)'.$min[0].'/', $text, $m, 0, $count))
                                        $count += strlen($m[0]) - 1;
                                break;
                        case '//':
                                $skip = strpos($text, "\n", $count);
                                if ($skip === false) $skip = strlen($text) - $count;
                                else $skip -= $count;
                                break;
                        case '/*':
                                if (preg_match('/\/\*.*?\*\//s', $text, $m, 0, $count)) {
                                        $skip = strlen($m[0]);
                                        $newlines = substr_count($m[0], "\n");
                                }
                                break;
                        }

                        if ($skip == 0) $count += strlen($min[0]);

                        $out .= substr($text, 0, $count).str_repeat("\n", $newlines);
                        $text = substr($text, $count + $skip);

                        $min = null;
                }

                return $out.$text;
        }

}

class lessc_formatter_classic {
        public $indentChar = "  ";

        public $break = "\n";
        public $open = " {";
        public $close = "}";
        public $selectorSeparator = ", ";
        public $assignSeparator = ":";

        public $openSingle = " { ";
        public $closeSingle = " }";

        public $disableSingle = false;
        public $breakSelectors = false;

        public $compressColors = false;

        public function __construct() {
                $this->indentLevel = 0;
        }

        public function indentStr($n = 0) {
                return str_repeat($this->indentChar, max($this->indentLevel + $n, 0));
        }

        public function property($name, $value) {
                return $name . $this->assignSeparator . $value . ";";
        }

        protected function isEmpty($block) {
                if (empty($block->lines)) {
                        foreach ($block->children as $child) {
                                if (!$this->isEmpty($child)) return false;
                        }

                        return true;
                }
                return false;
        }

        public function block($block) {
                if ($this->isEmpty($block)) return;

                $inner = $pre = $this->indentStr();

                $isSingle = !$this->disableSingle &&
                        is_null($block->type) && count($block->lines) == 1;

                if (!empty($block->selectors)) {
                        $this->indentLevel++;

                        if ($this->breakSelectors) {
                                $selectorSeparator = $this->selectorSeparator . $this->break . $pre;
                        } else {
                                $selectorSeparator = $this->selectorSeparator;
                        }

                        echo $pre .
                                implode($selectorSeparator, $block->selectors);
                        if ($isSingle) {
                                echo $this->openSingle;
                                $inner = "";
                        } else {
                                echo $this->open . $this->break;
                                $inner = $this->indentStr();
                        }

                }

                if (!empty($block->lines)) {
                        $glue = $this->break.$inner;
                        echo $inner . implode($glue, $block->lines);
                        if (!$isSingle && !empty($block->children)) {
                                echo $this->break;
                        }
                }

                foreach ($block->children as $child) {
                        $this->block($child);
                }

                if (!empty($block->selectors)) {
                        if (!$isSingle && empty($block->children)) echo $this->break;

                        if ($isSingle) {
                                echo $this->closeSingle . $this->break;
                        } else {
                                echo $pre . $this->close . $this->break;
                        }

                        $this->indentLevel--;
                }
        }
}

class lessc_formatter_compressed extends lessc_formatter_classic {
        public $disableSingle = true;
        public $open = "{";
        public $selectorSeparator = ",";
        public $assignSeparator = ":";
        public $break = "";
        public $compressColors = true;

        public function indentStr($n = 0) {
                return "";
        }
}

class lessc_formatter_lessjs extends lessc_formatter_classic {
        public $disableSingle = true;
        public $breakSelectors = true;
        public $assignSeparator = ": ";
        public $selectorSeparator = ",";
}