; <code class="code">pos_cnum</code> is the offset of the position (number of
   characters between the beginning of the lexbuf and the position).
   The difference between <code class="code">pos_cnum</code> and <code class="code">pos_bol</code> is the character
   offset within the line (i.e. the column number, assuming each
   character is one column wide).</p>

<p>See the documentation of type <code class="code">lexbuf</code> for information about
   how the lexing engine will manage positions.</p>
</div