[plt-scheme] conditional module inclusion and compilation

I've developed some code in DrScheme under Mac OS X that I also want  
to run sometimes under Linux -- it's computationally intensive stuff  
and I'll want to do development runs on my mac but then do lots of  
bigger runs on our Linux cluster.

I have some graphics in the Mac OS X version that I don't know how to  
produce in my command-line/text-based Linux environment, but I don't  
need the graphics there anyway. The graphics are just plots of  
progress which are useful when I'm developing and watching a run, but  
the cluster runs produce text files of data which are good enough. So  
to get the code working on the cluster I just removed "(require plot)"  
and all of the code that called anything from the plot module.

That worked but I don't want to have to do this kind of surgery on the  
code every time I move it to the cluster, which I'll be doing  
frequently. Ideally I'd like to be able to write my code in such a way  
that it knows where it's running and it includes the plot module and  
calls the plot code only if it's running somewhere appropriate. I do  
this in Common Lisp by using the #+: and #-: conditional compilation  
syntax and/or by looking for things in the variable *features*, which  
includes symbols that describe the environment. Is there anything  
similar in PLT?

I wouldn't mind having to manually change a flag to indicate the  
environment, e.g. to change the value in something like:

(define include-plots-in-reports #t)

But this doesn't actually help for two reasons:

- PLT won't let me wrap a call to "require" in a conditional  
expression -- it complains that it's not at the top level.
- If I comment out the "require" PLT still won't compile a file  
containing calls to functions in the missing module, even if those  
calls are never executed.

So whether my code knows where it's running or whether I have to tell  
it manually, I don't have a way of moving it to the Linux environment  
without manually editing out the "require" and all of the code that  
refers to the plot module.

Is there a good way to deal with this kind of thing in PLT that I'm  
missing?

Thanks,

  -Lee

--
Lee Spector, Professor of Computer Science
School of Cognitive Science, Hampshire College
893 West Street, Amherst, MA 01002-3359
lspector at hampshire.edu, http://hampshire.edu/lspector/
Phone: 413-559-5352, Fax: 413-559-5438

Check out Genetic Programming and Evolvable Machines:
http://www.springer.com/10710 - http://gpemjournal.blogspot.com/