re-using memory is old trick in Common Lisp application code. This is more "create a separate arena where we can allocate a ton of stuff and then drop it witho

re-using memory is old trick in Common Lisp application code. This is more "create a separate arena where we can allocate a ton of stuff and then drop it without actually going through collector". In fact, this is very similar to features provided in at least Symbolics Genera, which provided developer-created arenas as well.