do...until wisdom needed...

[Greg Ewing]

Douglas Alan wrote:
> 
> Debugging can be an issue.  Broken macros can be hard to debug.  A
> person who implements a macro should test his code well.

It's not just debugging the macro itself which is an issue,
it's debugging code which *uses* the macro. The user needs
to be given error messages which make sense to him without
having to know anything about how the macro is implemented.

Doing this well takes quite a lot of sophistication in the
macro system. Treating macros as simple textual substitutions
is completely inadequate.

Any proposed macro system for Python should include a detailed
discussion of how this issue is to be addressed!

-- 
Greg Ewing, Computer Science Dept, University of Canterbury,	  
Christchurch, New Zealand
To get my email address, please visit my web page:	  
http://www.cosc.canterbury.ac.nz/~greg