Class to simplify CPT and taxonomy creation including pluralizer algorithm

CPT taxonomy Class

<?php
/**
 * A small, quick class to make Custom Post Types and Taxonomies easier
 */
class CPT_Builder {

    static $plural = array(                          '/(quiz)$/i' => "$1zes",
        '/^(ox)$/i' => "$1en",                       '/([m|l])ouse$/i' => "$1ice",
        '/(matr|vert|ind)ix|ex$/i' => "$1ices",      '/(x|ch|ss|sh)$/i' => "$1es",
        '/([^aeiouy]|qu)y$/i' => "$1ies",            '/(hive)$/i' => "$1s",
        '/(?:([^f])fe|([lr])f)$/i' => "$1$2ves",     '/(shea|lea|loa|thie)f$/i' => "$1ves",
        '/sis$/i' => "ses",                          '/([ti])um$/i' => "$1a",
        '/(tomat|potat|ech|her|vet)o$/i' => "$1oes", '/(bu)s$/i' => "$1ses",
        '/(alias)$/i' => "$1es",                     '/(octop)us$/i' => "$1i",
        '/(ax|test)is$/i' => "$1es",                 '/(us)$/i' => "$1es",
        '/s$/i' => "s",                              '/$/' => "s", );
    static $irregular = array( 'move' => 'moves', 'foot' => 'feet', 'goose' => 'geese', 'sex' => 'sexes', 'child' => 'children', 'man' => 'men', 'tooth' => 'teeth', 'person' => 'people' );
    static $uncountable = array( 'sheep', 'fish', 'deer', 'series', 'species', 'money', 'rice', 'information', 'equipment' );

    function pluralize( $string ) {

// save some time in the case that singular and plural are the same
        if ( in_array( strtolower( $string ), self::$uncountable ) )
            return $string;

// check for irregular singular forms
        foreach ( self::$irregular as $pattern => $result ) {
            $pattern = '/' . $pattern . '$/i';

            if ( preg_match( $pattern, $string ) )
                return preg_replace( $pattern, $result, $string );
        }

// check for matches using regular expressions
        foreach ( self::$plural as $pattern => $result ) {
            if ( preg_match( $pattern, $string ) )
                return preg_replace( $pattern, $result, $string );
        }

        return $string;
    }

    /**
     * Provide smarter defaults for the core register_post_type function.
     *
     * @param string $post_type_name
     * @param string $name_space
     * @param array $args
     * @return string name of new post_type
     */
    function register_post_type( $post_type_name, $name_space, $args = array( ) ) {
        $name_space = sanitize_key( $name_space );
        $post_type_key = sanitize_key( $post_type_name );
        $post_type_plural = self::pluralize( $post_type_name );

        $defaults = array(
            'label' => $post_type_plural,
            'description' => $post_type_plural,
            'public' => true,
            'menu_position' => 21,
            'menu_icon' => get_bloginfo( 'template_url' ) . '/images/admin_' . $post_type_key . '.png',
            'supports' => array( 'title', 'editor', 'revisions', 'thumbnail' ),
            'register_meta_box_cb' => $post_type_key . '_meta_box_cb',
            'labels' => array(
                'name' => $post_type_plural,
                'singular_name' => $post_type_name,
                'add_new' => 'Add ' . $post_type_name,
                'add_new_item' => 'Add New ' . $post_type_name,
                'edit_item' => 'Edit ' . $post_type_name,
                'new_item' => 'New ' . $post_type_name,
                'view_item' => 'View ' . $post_type_name,
                'search_items' => 'Search ' . $post_type_plural,
                'not_found' => 'No ' . $post_type_plural . ' found',
                'not_found_in_trash' => 'No ' . $post_type_plural . ' found in Trash'
            ),
            'show_in_nav_menus' => false,
            'hierarchical' => true,
            /* The rest of these can be set if needed by passing them in the $args variable -
             * listed here for reference: 'publicly_queryable', 'exclude_from_search', 'taxonomies',
             * 'show_ui', 'show_in_nav_menus', 'show_in_menu', 'show_in_admin_bar',
             */
            );
        $args = wp_parse_args( $args, $defaults );

        register_post_type( $name_space . '_' . $post_type_key, $args );
        return $name_space . '_' . $post_type_key;
    }

    function register_taxonomy( $taxonomy_name, $post_type, $name_space ) {
        $name_space = sanitize_key( $name_space );
        $taxonomy_key = sanitize_key( $taxonomy_name );
        $taxonomy_plural = self::pluralize( $taxonomy_name );

        register_taxonomy( $name_space . '_' . $taxonomy_key, $post_type, array(
            'label' => $taxonomy_plural,
            'hierarchical' => true,
            'rewrite' => false,
            'labels' => array(
                'name' => $taxonomy_plural,
                'singular_name' => $taxonomy_name,
                'search_items' => 'Search ' . $taxonomy_plural,
                'all_items' => 'All ' . $taxonomy_plural,
                'parent_item' => 'Parent ' . $taxonomy_name,
                'parent_item_colon' => 'Parent ' . $taxonomy_name . ':',
                'edit_item' => 'Edit ' . $taxonomy_name,
                'update_item' => 'Update ' . $taxonomy_name,
                'add_new_item' => 'Add New ' . $taxonomy_name,
                'new_item_name' => 'New ' . $taxonomy_name
            )
        ) );
    }

}

// *** Usage ***
function plugin_init() {
    $testimonials = CPT_Builder::register_post_type( "Testimonial", 'plugin', array(
                'supports' => array( 'editor' ),
            ) );
}

add_action( 'init', 'plugin_init' );