Using MongoRegex vs Javascript Expression $where

gistfile1.aw

<?php
//With proper Indexing this will be a lot faster than JS Expression
$categoryInput = strtolower($postedFromSomeWhere);
$categoryInput = preg_quote($categoryInput);
$regex = new MongoRegex ('/^'. $categoryInput .'$/i');

$categoryModel = new Category;

$rs = $categoryModel->findOne(
    'username' => 'leng',
    'category' => $regex,
);