wiki.techinc.nl/languages/classes/LanguageRu.php

<?php
/** Russian (русский язык)
  *
  * You can contact Alexander Sigachov (alexander.sigachov at Googgle Mail)
  *
  * @addtogroup Language
  */

/* Please, see Language.php for general function comments */
class LanguageRu extends Language {
	# Convert from the nominative form of a noun to some other case
	# Invoked with {{grammar:case|word}}
	function convertGrammar( $word, $case ) {
		global $wgGrammarForms;
		if ( isset($wgGrammarForms['ru'][$case][$word]) ) {
			return $wgGrammarForms['ru'][$case][$word];
		}

		# These rules are not perfect, but they are currently only used for site names so it doesn't
		# matter if they are wrong sometimes. Just add a special case for your site name if necessary.

		#join and array_slice instead mb_substr
		$ar = array();
		preg_match_all( '/./us', $word, $ar );
		if (!preg_match("/[a-zA-Z_]/us", $word))
			switch ( $case ) {
				case 'genitive': #родительный падеж
					if ((join('',array_slice($ar[0],-4))=='вики') || (join('',array_slice($ar[0],-4))=='Вики'))
						{}
					elseif (join('',array_slice($ar[0],-1))=='ь')
						$word = join('',array_slice($ar[0],0,-1)).'я';
					elseif (join('',array_slice($ar[0],-2))=='ия')
						$word=join('',array_slice($ar[0],0,-2)).'ии';
					elseif (join('',array_slice($ar[0],-2))=='ка')
						$word=join('',array_slice($ar[0],0,-2)).'ки';
					elseif (join('',array_slice($ar[0],-2))=='ти')
						$word=join('',array_slice($ar[0],0,-2)).'тей';
					elseif (join('',array_slice($ar[0],-2))=='ды')
						$word=join('',array_slice($ar[0],0,-2)).'дов';
					elseif (join('',array_slice($ar[0],-3))=='ник')
						$word=join('',array_slice($ar[0],0,-3)).'ника';
					break;
				case 'dative':  #дательный падеж
					#stub
					break;
				case 'accusative': #винительный падеж
					#stub
					break;
				case 'instrumental':  #творительный падеж
					#stub
					break;
				case 'prepositional': #предложный падеж
					#stub
					break;
			}
		return $word;
	}

	function convertPlural( $count, $wordform1, $wordform2, $wordform3, $w4, $w5) {
		$count = str_replace (' ', '', $count);
		if ($count > 10 && floor(($count % 100) / 10) == 1) {
			return $wordform3;
		} else {
			switch ($count % 10) {
				case 1: return $wordform1;
				case 2:
				case 3:
				case 4: return $wordform2;
				default: return $wordform3;
			}
		}
	}

	/*
	 * Russian numeric format is "12 345,67" but "1234,56"
	 */

	function commafy($_) {
		if (!preg_match('/^\d{1,4}$/',$_)) {
			return strrev((string)preg_replace('/(\d{3})(?=\d)(?!\d*\.)/','$1,',strrev($_)));
		} else {
			return $_;
		}
	}
}