erated when the
   end of the string is reached.</p>
</div>
</div>

<pre id="VALfrom_function">val from_function : ?with_positions:bool -&gt; (bytes -&gt; int -&gt; int) -&gt; lexbuf</pre><div class="info ">
<div class="info-desc">
<p>Create a lexer buffer with the given function as its reading method.
   When the scanner needs more characters, it will call the given
   function, giving it a byte sequence <code class="code">s</code> and a byte
   count <code class="code">n</code>. The function should put <c