Overtrue\Pinyin\Pinyin::splitWords PHP Method

    public function splitWords($pinyin, $option)
    {
        $split = array_filter(preg_split('/[^üāēīōūǖáéíóúǘǎěǐǒǔǚàèìòùǜa-z\\d]+/iu', $pinyin));
        if ($option !== self::UNICODE) {
            foreach ($split as $index => $pinyin) {
                $split[$index] = $this->format($pinyin, $option === self::ASCII);
            }
        }
        return array_values($split);
    }