push-style APIs</b>: a C&nbsp;function repeatedly
calling a callback for each result. Instead <b>use pull-style APIs</b>:
call a C&nbsp;function repeatedly to get a new result. Calls from Lua
to C via the FFI are much faster than the other way round. Most well-designed
libraries already use pull-style APIs (read/write, get/put).
</p>

<h2 id="clib">C Library Namespaces</h2>
<p>
A C&nbsp;library namespace is a special kind of object which allows
access to the symbols contained in shared libraries or the defa