Re: Dynamic updating

[Doug Orleans <dougo@ccs.neu.edu>]

Eli Barzilay writes:
 > BTW, one thing I found useful is a `defvar' macro that defines an
 > object only if it is not already defined.

I assume you use namespace-defined? (from MzLib's etc.ss) to implement
this-- or does it also handle definitions that aren't at the top
level?  I've been thinking about trying to use identifier-binding to
do this, but haven't gotten around to seeing if it would work.
I guess what I'm saying is, I'd like to se your "defvar" definition...

--dougo@ccs.neu.edu