ns the integer value of a base 10 digit.
        </li>
        <li>
          <b>CH_TO_DIGIT_BIN</b> returns the integer value of a binary digit.
        </li>
        <li>
          <b>CH_TO_DIGIT_HEX</b> returns the integer value of a hexadecimal digit.
        </li>
        <li>
          <b>CH_TO_DIGIT_OCT</b> returns the integer value of an octal digit.
        </li>
        <li>
          <b>CH_TO_ROT13</b> converts a character to its ROT13 equivalent.
        </li>
        <li>
          <b>CH_TO_SCR