codejobs - Singularize words

singularize.php

<?php
function singularize($word) {
	$uncountable = array("sheep",
			     "fish",
			     "deer",
			     "series",
			     "species",
			     "money",
			     "rice",
			     "information",
			     "equipment"
	);	
	
	$irregular = array(	"move"   => "moves",
				"foot"   => "feet",
				"goose"  => "geese",
				"sex"    => "sexes",
				"child"  => "children",
				"man"    => "men",
				"tooth"  => "teeth",
				"person" => "people"
	);	

	$singular = array(	"/(quiz)zes$/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"                      => ""
	);	
	
	if(in_array(strtolower($word), $uncountable)) {
		return $word;
	}

	foreach($irregular as $result => $pattern) {
		$pattern = "/$pattern$/i";
		
		if(preg_match($pattern, $word)) {
			return preg_replace($pattern, $result, $word);
		}
	}

	foreach($singular as $pattern => $result) {
		if(preg_match($pattern, $word)) {
			return preg_replace($pattern, $result, $word);
		}
	}
	
	return $word;
}
?>