From: rcoder <rcoder@...>
Date: 2005-07-21T02:00:56+09:00
Subject: Re: IRB reset?

You can also put a sigil on the const_remove calls to prevent them from
being executed except when running in IRB:

--- begin ---

if (defined? IRB && IRB.CurrentContext)
  const_remove :FOO
end

--- end ---

That would allow you to undefine the constants only while in a
currently-running IRB session, while still seeing warnings when your
"production" system (which presumably won't be running inside IRB)
loads a library multiple times.

As for resetting the IRB state, I think you're probably best off simple
exiting and restarting the process, esp. if you have the readline
extensions enabled. You'll still have your command history, and can use
the up and down arrow keys to re-execute any commands from your
previous session.

-Lennon