 transform it into some other
source code, usually automating some repetitive pattern for you.
</p>
<h2 id="Optional-arguments">Optional arguments
</h2>
<p>Most Janet functions will raise an error at runtime if not passed exactly the
right number of arguments.  Sometimes, you want to define a function with
optional arguments, where the arguments take a default value if not supplied by
the caller. Janet has support for this via the <code class="mendoza-code">&amp;opt</code> symbol in parameter
lists, where a