return ".*" + appendFileterPath(buf, escape(v)) + ".*";
        }
        if (s.startsWith(REGEXP_IGNORE_CASE)) {
            final String v = s.substring(REGEXP_IGNORE_CASE.length());
            final StringBuilder buf = new StringBuilder(100);
            buf.append("(?i)");
            return appendFileterPath(buf, unescape(v));
        }
        if (s.startsWith(REGEXP_CASE)) {