PhpParser\Comment::getShortestWhitespacePrefixLen PHP Method

    private function getShortestWhitespacePrefixLen($str)
    {
        $lines = explode("\n", $str);
        $shortestPrefixLen = INF;
        foreach ($lines as $line) {
            preg_match('(^\\s*)', $line, $matches);
            $prefixLen = strlen($matches[0]);
            if ($prefixLen < $shortestPrefixLen) {
                $shortestPrefixLen = $prefixLen;
            }
        }
        return $shortestPrefixLen;
    }