 ASCII printable range (32..126) are
    escaped, as well as backslash and double-quote.</p>
</div>
<ul class="info-attributes">
<li><b>Raises</b> <code>Invalid_argument</code> if the result is longer than
    <a href="Sys.html#VALmax_string_length"><code class="code">Sys.max_string_length</code></a> bytes.</li>
</ul>
</div>

<pre id="VALindex">val index : bytes -&gt; char -&gt; int</pre><div class="info ">
<div class="info-desc">
<p><code class="code">index&nbsp;s&nbsp;c</code> returns the index of the fir