Twig Inflector Extension - For plural and singular English words

Inflector.php

<?php
/**
 * ReadySetData 2009-2013
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 * User: Bryan Green
 * Date: 2/14/13
 * Time: 2:10 AM
 */

// Thanks to http://www.eval.ca/articles/php-pluralize (MIT license)
//           http://dev.rubyonrails.org/browser/trunk/activesupport/lib/active_support/inflections.rb (MIT license)
//           http://www.fortunecity.com/bally/durrus/153/gramch13.html
//           http://www2.gsu.edu/~wwwesl/egw/crump.htm
//
// Changes (2013-02-14) - by: Bryan Green
//  Formatted code
//  Added "software" to uncountable list
//
// Changes (12/17/07)
//   Major changes
//   --
//   Fixed irregular noun algorithm to use regular expressions just like the original Ruby source.
//       (this allows for things like fireman -> firemen
//   Fixed the order of the singular array, which was backwards.
//
//   Minor changes
//   --
//   Removed incorrect pluralization rule for /([^aeiouy]|qu)ies$/ => $1y
//   Expanded on the list of exceptions for *o -> *oes, and removed rule for buffalo -> buffaloes
//   Removed dangerous singularization rule for /([^f])ves$/ => $1fe
//   Added more specific rules for singularizing lives, wives, knives, sheaves, loaves, and leaves and thieves
//   Added exception to /(us)es$/ => $1 rule for houses => house and blouses => blouse
//   Added excpetions for feet, geese and teeth
//   Added rule for deer -> deer

// Changes:
//   Removed rule for virus -> viri
//   Added rule for potato -> potatoes
//   Added rule for *us -> *uses

class Inflect
{
  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 $singular = array(
    '/(quiz)zes$/i'                                                    => "$1",
    '/(matr)ices$/i'                                                   => "$1ix",
    '/(vert|ind)ices$/i'                                               => "$1ex",
    '/^(ox)en$/i'                                                      => "$1",
    '/(alias)es$/i'                                                    => "$1",
    '/(octop|vir)i$/i'                                                 => "$1us",
    '/(cris|ax|test)es$/i'                                             => "$1is",
    '/(shoe)s$/i'                                                      => "$1",
    '/(o)es$/i'                                                        => "$1",
    '/(bus)es$/i'                                                      => "$1",
    '/([m|l])ice$/i'                                                   => "$1ouse",
    '/(x|ch|ss|sh)es$/i'                                               => "$1",
    '/(m)ovies$/i'                                                     => "$1ovie",
    '/(s)eries$/i'                                                     => "$1eries",
    '/([^aeiouy]|qu)ies$/i'                                            => "$1y",
    '/([lr])ves$/i'                                                    => "$1f",
    '/(tive)s$/i'                                                      => "$1",
    '/(hive)s$/i'                                                      => "$1",
    '/(li|wi|kni)ves$/i'                                               => "$1fe",
    '/(shea|loa|lea|thie)ves$/i'                                       => "$1f",
    '/(^analy)ses$/i'                                                  => "$1sis",
    '/((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$/i' => "$1$2sis",
    '/([ti])a$/i'                                                      => "$1um",
    '/(n)ews$/i'                                                       => "$1ews",
    '/(h|bl)ouses$/i'                                                  => "$1ouse",
    '/(corpse)s$/i'                                                    => "$1",
    '/(us)es$/i'                                                       => "$1",
    '/s$/i'                                                            => ""
  );

  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',
    'software',
    'now'
  );

  public static 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;
  }

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

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

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

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

    return $string;
  }

  public static function pluralize_if($count, $string)
  {
    if ($count == 1)
      return "1 $string";
    else
      return $count . " " . self::pluralize($string);
  }
}

InflectorUtil.php

<?php
include_once('./utils/Inflector.php');

/**
 * Class Twig_Extension_Inflector
 */
class Twig_Extension_Inflector extends Twig_Extension
{

  const PLURALIZE   = 'pluralize';
  const SINGULARIZE = 'singularize';

  public function getName()
  {
    return self::PLURALIZE;
  }

  public function getFilters()
  {
    return array(
      self::PLURALIZE   => new \Twig_Filter_Method($this, self::PLURALIZE, array(
                                                                                'pre_escape' => 'html',
                                                                                'is_safe'    => array('all')
                                                                           )),
      self::SINGULARIZE => new \Twig_Filter_Method($this, self::SINGULARIZE, array(
                                                                                  'pre_escape' => 'html',
                                                                                  'is_safe'    => array('all')
                                                                             ))

    );
  }

  /**
   * Converts a word into its plural form
   *
   * @param $text
   * @param null $count
   *
   * @return string
   */
  public function pluralize($text, $count = null)
  {
    $handback = $text;

    if (!empty($text)) {
      if (is_numeric($count)) {
        $handback = Inflect::pluralize_if($count, $text);
      } else {
        $handback = Inflect::pluralize($text);
      }
    }

    return $handback;
  }


  /**
   * Converts a word into its singular form
   *
   * @param $text
   *
   * @return string
   */
  public function singularize($text)
  {
    $handback = $text;

    if (!empty($text)) {
      $handback = Inflect::singularize($text);
    }

    return $handback;
  }

}

This is amazing, thanks a lot!