verses the characters in a string.
        </li>
        <li>
          <b>S_TO_I4</b> reads an I4 from a string.
        </li>
        <li>
          <b>S_TO_I4VEC</b> reads an I4VEC from a string.
        </li>
        <li>
          <b>S_TO_L</b> reads a logical value from a string.
        </li>
        <li>
          <b>S_TO_R4</b> reads an R4 from a string.
        </li>
        <li>
          <b>S_TO_R4VEC</b> reads an R4VEC from a string.
        </li>
        <li>
          <b>S_TO_R8</b> reads an 