rhymix/vendor/leafo/lessphp/tests/sort.php

<?php
error_reporting(E_ALL);

require realpath(dirname(__FILE__)) . '/../lessc.inc.php';

// sorts the selectors in stylesheet in order to normalize it for comparison

$exe = array_shift($argv); // remove filename

if (!$fname = array_shift($argv)) {
    $fname = "php://stdin";
}

class lesscNormalized extends lessc {
    public $numberPrecision = 3;

    public function compileValue($value) {
        if ($value[0] === "raw_color") {
            $value = $this->coerceColor($value);
        }

        return parent::compileValue($value);
    }
}

class SortingFormatter extends lessc_formatter_lessjs {
    public function sortKey($block) {
        if (!isset($block->sortKey)) {
            sort($block->selectors, SORT_STRING);
            $block->sortKey = implode(",", $block->selectors);
        }

        return $block->sortKey;
    }

    public function sortBlock($block) {
        usort($block->children, function($a, $b) {
            $sort = strcmp($this->sortKey($a), $this->sortKey($b));
            if ($sort == 0) {
                // TODO
            }
            return $sort;
        });

    }

    public function block($block) {
        $this->sortBlock($block);
        return parent::block($block);
    }

}

$less = new lesscNormalized();
$less->setFormatter(new SortingFormatter);
echo $less->parse(file_get_contents($fname));