public static boolean isDotQuadIP(final String hostname) {
        if (Character.isDigit(hostname.charAt(0))) {
            int i, len, dots;
            char[] data;

            i = dots = 0; /* quick IP address validation */
            len = hostname.length();
            data = hostname.toCharArray();
            while (i < len && Character.isDigit(data[i++])) {
                if (i == len && dots == 3) {

                buildNumber = null;
            }
        }
    }

    private static boolean isDigits(String cs) {
        if (cs == null || cs.isEmpty()) {
            return false;
        }
        final int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isDigit(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

		return true
	case '\u2215': // Represents the slash in runtime/debug.setGCPercent. U+2215 '∕' division slash
		return true
	}
	// Digits are OK only after the first character.
	return i > 0 && unicode.IsDigit(ch)
}

func (t *Tokenizer) Text() string {
	switch t.tok {
	case LSH:
		return "<<"
	case RSH:
		return ">>"
	case ARR:
		return "->"
	case ROT:
		return "@>"
	}
	return t.s.TokenText()

                    throw new IOException("no lmhosts alternate includes loaded");
                }
            } else if (Character.isDigit(line.charAt(0))) {
                final char[] data = line.toCharArray();
                int ip, i, j;
                Name name;
                NbtAddress addr;
                char c = '.';

                    alt--;
                    throw new IOException("no lmhosts alternate includes loaded");
                }
            } else if (Character.isDigit(line.charAt(0))) {
                final char[] data = line.toCharArray();
                int ip, i, j;
                Name name;
                NbtAddress addr;
                char c = '.';

   *   <li>All other characters are converted into one or more bytes using UTF-8 encoding and each
   *       byte is then represented by the 3-character string "%XY", where "XY" is the two-digit,
   *       uppercase, hexadecimal representation of the byte value.
   * </ul>
   *
   * <p>This escaper is suitable for escaping parameter names and values even when <a

        if (pos == limit) return false // Malformed.
        val c = string[pos++]
        val digit =
          when (c) {
            in 'a'..'z' -> c - 'a'
            in 'A'..'Z' -> c - 'A'
            in '0'..'9' -> c - '0' + 26
            else -> return false // Malformed.
          }
        val deltaI = digit * w
        if (i > Int.MAX_VALUE - deltaI) return false // Prevent overflow.
        i += deltaI

    WHITESPACE(CharMatcher.whitespace(), WHITESPACE_CHARACTERS),
    HASH(CharMatcher.is('#'), "#"),
    ASCII(CharMatcher.ascii(), ASCII_CHARACTERS),
    WESTERN_DIGIT("0123456789"),
    ALL_DIGIT(CharMatcher.digit(), ALL_DIGITS),
    OPS_5("+-*/%"),
    HEX_16(CharMatcher.inRange('0', '9').or(CharMatcher.inRange('A', 'F')), "0123456789ABCDEF"),
    HEX_22(
        CharMatcher.inRange('0', '9')

   *   <li>All other characters are converted into one or more bytes using UTF-8 encoding and each
   *       byte is then represented by the 3-character string "%XY", where "XY" is the two-digit,
   *       uppercase, hexadecimal representation of the byte value.
   * </ul>
   *
   * <p>This escaper is suitable for escaping parameter names and values even when <a

    /**
     * ISO 8601 extended UTC format: yyyy-MM-dd'T'HH:mm:ss.SSS'Z'
     */
    public static final String DATE_FORMAT_ISO_8601_EXTEND_UTC = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'";

    /**
     * Digit only date format: yyyyMMddHHmmss
     */
    public static final String DATE_FORMAT_DIGIT_ONLY = "yyyyMMddHHmmss";

    /**
     * Do not instantiate.
     */
    protected CoreLibConstants() {
    }