Overtrue\Pinyin\Pinyin::format PHP Метод

    protected function format($pinyin, $tone = false)
    {
        $replacements = array('üē' => array('ue', 1), 'üé' => array('ue', 2), 'üě' => array('ue', 3), 'üè' => array('ue', 4), 'ā' => array('a', 1), 'ē' => array('e', 1), 'ī' => array('i', 1), 'ō' => array('o', 1), 'ū' => array('u', 1), 'ǖ' => array('v', 1), 'á' => array('a', 2), 'é' => array('e', 2), 'í' => array('i', 2), 'ó' => array('o', 2), 'ú' => array('u', 2), 'ǘ' => array('v', 2), 'ǎ' => array('a', 3), 'ě' => array('e', 3), 'ǐ' => array('i', 3), 'ǒ' => array('o', 3), 'ǔ' => array('u', 3), 'ǚ' => array('v', 3), 'à' => array('a', 4), 'è' => array('e', 4), 'ì' => array('i', 4), 'ò' => array('o', 4), 'ù' => array('u', 4), 'ǜ' => array('v', 4));
        foreach ($replacements as $unicde => $replacements) {
            if (false !== strpos($pinyin, $unicde)) {
                $pinyin = str_replace($unicde, $replacements[0], $pinyin) . ($tone ? $replacements[1] : '');
            }
        }
        return $pinyin;
    }