>.
Otherwise returns nil.
</p>

<h3><a name="f-version"></a><code>lpeg.version ()</code></h3>
<p>
Returns a string with the running version of LPeg.
</p>

<h3><a name="f-setstack"></a><code>lpeg.setmaxstack (max)</code></h3>
<p>
Sets the maximum size for the backtrack stack used by LPeg to
track calls and choices.
Most well-written patterns need little backtrack levels and
therefore you seldom need to change this maximum;
but a few useful patterns may need more space.
Before changing this maximum you should