wiki.techinc.nl/includes/languages/LanguageJa.php

<?php
/**
 * Japanese (日本語) specific code.
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Language
 */

/**
 * Japanese (日本語)
 *
 * @ingroup Language
 */
class LanguageJa extends Language {

	/**
	 * @param string $string
	 * @return string
	 */
	public function segmentByWord( $string ) {
		// Strip known punctuation ?
		// $s = preg_replace( '/\xe3\x80[\x80-\xbf]/', '', $s ); # U3000-303f

		// Space strings of like hiragana/katakana/kanji
		$hiragana = '(?:\xe3(?:\x81[\x80-\xbf]|\x82[\x80-\x9f]))'; # U3040-309f
		$katakana = '(?:\xe3(?:\x82[\xa0-\xbf]|\x83[\x80-\xbf]))'; # U30a0-30ff
		$kanji = '(?:\xe3[\x88-\xbf][\x80-\xbf]'
			. '|[\xe4-\xe8][\x80-\xbf]{2}'
			. '|\xe9[\x80-\xa5][\x80-\xbf]'
			. '|\xe9\xa6[\x80-\x99])';
			# U3200-9999 = \xe3\x88\x80-\xe9\xa6\x99
		$reg = "/({$hiragana}+|{$katakana}+|{$kanji}+)/";
		$s = self::insertSpace( $string, $reg );
		return $s;
	}

	/**
	 * Italic is not appropriate for Japanese script
	 * Unfortunately most browsers do not recognise this, and render `<em>` as italic
	 *
	 * @param string $text
	 * @return string
	 */
	public function emphasize( $text ) {
		return $text;
	}
}