Improved plural() and singular().
Avoids double-pluralization using "uncountable words" and better logic.
diff --git a/system/helpers/inflector_helper.php b/system/helpers/inflector_helper.php
index 2069a19..02c425b 100644
--- a/system/helpers/inflector_helper.php
+++ b/system/helpers/inflector_helper.php
@@ -34,7 +34,7 @@
  * @subpackage	Helpers
  * @category	Helpers
  * @author		EllisLab Dev Team
- * @link		http://codeigniter.com/user_guide/helpers/directory_helper.html
+ * @link		http://codeigniter.com/user_guide/helpers/inflector_helper.html
  */
 
 
@@ -45,7 +45,6 @@
  *
  * Takes a plural word and makes it singular
  *
- * @access	public
  * @param	string
  * @return	str
  */
@@ -55,37 +54,51 @@
 	{
 		$result = strval($str);
 
+		if ( ! is_countable($result))
+		{
+			return $result;
+		}
+		
 		$singular_rules = array(
-			'/(matr)ices$/'			=> '\1ix',
-			'/(vert|ind)ices$/'		=> '\1ex',
-			'/^(ox)en/'				=> '\1',
-			'/(alias)es$/'			=> '\1',
-			'/([octop|vir])i$/'		=> '\1us',
-			'/(cris|ax|test)es$/'	=> '\1is',
-			'/(shoe)s$/'			=> '\1',
-			'/(o)es$/'				=> '\1',
-			'/(bus|campus)es$/'		=> '\1',
-			'/([m|l])ice$/'			=> '\1ouse',
-			'/(x|ch|ss|sh)es$/'		=> '\1',
-			'/(m)ovies$/'			=> '\1\2ovie',
-			'/(s)eries$/'			=> '\1\2eries',
-			'/([^aeiouy]|qu)ies$/'	=> '\1y',
-			'/([lr])ves$/'			=> '\1f',
-			'/(tive)s$/'			=> '\1',
-			'/(hive)s$/'			=> '\1',
-			'/([^f])ves$/'			=> '\1fe',
-			'/(^analy)ses$/'		=> '\1sis',
+			'/(matr)ices$/'         => '\1ix',
+			'/(vert|ind)ices$/'     => '\1ex',
+			'/^(ox)en/'             => '\1',
+			'/(alias)es$/'          => '\1',
+			'/([octop|vir])i$/'     => '\1us',
+			'/(cris|ax|test)es$/'   => '\1is',
+			'/(shoe)s$/'            => '\1',
+			'/(o)es$/'              => '\1',
+			'/(bus|campus)es$/'     => '\1',
+			'/([m|l])ice$/'         => '\1ouse',
+			'/(x|ch|ss|sh)es$/'     => '\1',
+			'/(m)ovies$/'           => '\1\2ovie',
+			'/(s)eries$/'           => '\1\2eries',
+			'/([^aeiouy]|qu)ies$/'  => '\1y',
+			'/([lr])ves$/'          => '\1f',
+			'/(tive)s$/'            => '\1',
+			'/(hive)s$/'            => '\1',
+			'/([^f])ves$/'          => '\1fe',
+			'/(^analy)ses$/'        => '\1sis',
 			'/((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$/' => '\1\2sis',
-			'/([ti])a$/'			=> '\1um',
-			'/(p)eople$/'			=> '\1\2erson',
-			'/(m)en$/'				=> '\1an',
-			'/(s)tatuses$/'			=> '\1\2tatus',
-			'/(c)hildren$/'			=> '\1\2hild',
-			'/(n)ews$/'				=> '\1\2ews',
-			'/([^u])s$/'			=> '\1',
+			'/([ti])a$/'            => '\1um',
+			'/(p)eople$/'           => '\1\2erson',
+			'/(m)en$/'              => '\1an',
+			'/(s)tatuses$/'         => '\1\2tatus',
+			'/(c)hildren$/'         => '\1\2hild',
+			'/(n)ews$/'             => '\1\2ews',
+			'/([^us])s$/'           => '\1',
 		);
 
-		return preg_replace(array_keys($singular_rules), $singular_rules, $result);
+		foreach ($singular_rules as $rule => $replacement)
+		{
+			if (preg_match($rule, $result))
+			{
+				$result = preg_replace($rule, $replacement, $result);
+				break;
+			}
+		}
+
+		return $result;
 	}
 }
 
@@ -96,7 +109,6 @@
  *
  * Takes a singular word and makes it plural
  *
- * @access	public
  * @param	string
  * @param	bool
  * @return	str
@@ -104,32 +116,46 @@
 if ( ! function_exists('plural'))
 {
 	function plural($str, $force = FALSE)
-	{
+	{	
 		$result = strval($str);
 
-		$plural_rules = array(
-			'/^(ox)$/'					=> '\1\2en',	 // ox
-			'/([m|l])ouse$/'			=> '\1ice',	  // mouse, louse
-			'/(matr|vert|ind)ix|ex$/'	=> '\1ices',	 // matrix, vertex, index
-			'/(x|ch|ss|sh)$/'			=> '\1es',	   // search, switch, fix, box, process, address
-			'/([^aeiouy]|qu)y$/'		=> '\1ies',	  // query, ability, agency
-			'/(hive)$/'					=> '\1s',		// archive, hive
-			'/(?:([^f])fe|([lr])f)$/'	=> '\1\2ves',	// half, safe, wife
-			'/sis$/'					=> 'ses',		// basis, diagnosis
-			'/([ti])um$/'				=> '\1a',		// datum, medium
-			'/(p)erson$/'				=> '\1eople',	// person, salesperson
-			'/(m)an$/'					=> '\1en',	   // man, woman, spokesman
-			'/(c)hild$/'				=> '\1hildren',  // child
-			'/(buffal|tomat)o$/'		=> '\1\2oes',	// buffalo, tomato
-			'/(bu|campu)s$/'			=> '\1\2ses',	// bus, campus
-			'/(alias|status|virus)/'	=> '\1es',	   // alias
-			'/(octop)us$/'				=> '\1i',		// octopus
-			'/(ax|cris|test)is$/'		=> '\1es',	   // axis, crisis
-			'/s$/'						=> 's',		  // no change (compatibility)
-			'/$/'						=> 's',
-		);
+		if ( ! is_countable($result))
+		{
+			return $result;
+		}
 
-		return preg_replace(array_keys($plural_rules), $plural_rules, $result);
+		$plural_rules = array(
+			'/^(ox)$/'                 => '\1\2en',     // ox
+			'/([m|l])ouse$/'           => '\1ice',      // mouse, louse
+			'/(matr|vert|ind)ix|ex$/'  => '\1ices',     // matrix, vertex, index
+			'/(x|ch|ss|sh)$/'          => '\1es',       // search, switch, fix, box, process, address
+			'/([^aeiouy]|qu)y$/'       => '\1ies',      // query, ability, agency
+			'/(hive)$/'                => '\1s',        // archive, hive
+			'/(?:([^f])fe|([lr])f)$/'  => '\1\2ves',    // half, safe, wife
+			'/sis$/'                   => 'ses',        // basis, diagnosis
+			'/([ti])um$/'              => '\1a',        // datum, medium
+			'/(p)erson$/'              => '\1eople',    // person, salesperson
+			'/(m)an$/'                 => '\1en',       // man, woman, spokesman
+			'/(c)hild$/'               => '\1hildren',  // child
+			'/(buffal|tomat)o$/'       => '\1\2oes',    // buffalo, tomato
+			'/(bu|campu)s$/'           => '\1\2ses',    // bus, campus
+			'/(alias|status|virus)$/'  => '\1es',       // alias
+			'/(octop)us$/'             => '\1i',        // octopus
+			'/(ax|cris|test)is$/'      => '\1es',       // axis, crisis
+			'/s$/'                     => 's',          // no change (compatibility)
+			'/$/'                      => 's',
+		);
+		
+		foreach ($plural_rules as $rule => $replacement)
+		{
+			if (preg_match($rule, $result))
+			{
+				$result = preg_replace($rule, $replacement, $result);
+				break;
+			}
+		}
+
+		return $result;
 	}
 }
 
@@ -140,7 +166,6 @@
  *
  * Takes multiple words separated by spaces or underscores and camelizes them
  *
- * @access	public
  * @param	string
  * @return	str
  */
@@ -159,7 +184,6 @@
  *
  * Takes multiple words separated by spaces and underscores them
  *
- * @access	public
  * @param	string
  * @return	str
  */
@@ -178,7 +202,6 @@
  *
  * Takes multiple words separated by the separator and changes them to spaces
  *
- * @access	public
  * @param	string $str
  * @param 	string $separator
  * @return	str
@@ -191,5 +214,22 @@
 	}
 }
 
+/**
+ * Checks if the given word has a plural version.
+ *
+ * @param   string  the word to check
+ * @return  bool    if the word is countable
+ */
+if ( ! function_exists('is_countable'))
+{
+	function is_countable($word)
+	{
+		return ! (in_array(strtolower(strval($word)), array(
+			'equipment', 'information', 'rice', 'money',
+			'species', 'series', 'fish', 'meta'
+		)));
+	}
+}
+
 /* End of file inflector_helper.php */
-/* Location: ./system/helpers/inflector_helper.php */
+/* Location: ./system/helpers/inflector_helper.php */
\ No newline at end of file