quicker search of namespace array in universal class loader

gistfile1.aw

<?php
            foreach ($this->namespaces as $ns => $dirs) {
                if (0 !== strpos($namespace, $ns)) {
                    continue;
                }

                foreach ($dirs as $dir) {
                    $file = $dir.DIRECTORY_SEPARATOR.$normalizedClass;
                    if (is_file($file)) {
                        return $file;
                    }
                }
            }

// vs.

            if (isset($this->namespaces[$namespace])) {
                foreach ($this->namespaces[$namespace] as $dir) {
                    $file = $dir.DIRECTORY_SEPARATOR.$normalizedClass;
                    if (is_file($file)) {
                        return $file;
                    }
                }
            }