meta None?

[Tripp Lilley]

Continuing with the "what the hell is he /doing/, anyway?" theme, I'll
offer another distraction :)

I'd like to implement a meta-None class... that is, a class that behaves
like None regardless of what you subject it to:

	1: print metaNone		# displays 'None'
	2: print metaNone( )	# displays 'None'

	3: if metaNone is None: print "yes"	# displays 'yes'
	4: if metaNone( ) is None: print "yes"	# displays 'yes'

and so forth.

I understand how to get behaviours 1, 2, and 4 by overloading __repr__
and __call__. How would I get behaviour 3? I haven't found anything in a
cursory search of my literature suggesting I can overload "is".

Thanks again!

-- 
Tripp Lilley * tripp at perspex.com *
http://stargate.eheart.sg505.net/~tlilley/
-----------------------------------------------------------------------------
"This whole textual substitution thing is pissing me off.
 I feel like I'm programming in Tcl."

- Eric Frias, former roommate, hacking partner extraordinaire