Meta programming question

[Bruce Dickey]

"David Abrahams" <dave at boost-consulting.com> wrote in message
news:ufzih2ali.fsf at boost-consulting.com...
> Bruce Dickey <ceiesa at excite.com> writes:
>
> > Ben Finney wrote:
> >> On Sat, 27 Sep 2003 19:18:15 -0600, Bruce Dickey wrote:
> >>
> >>>I've read a number of the meta progamming articles. I have not found
> >>>what I am looking for. I want to override assignments to variables
> >>>which are in the module namespace (not object members -- no classes
> >>>involved).  Can this be done?
> >> AFAIK, no.  If it were possible, it would be very confusing.
> >> What is it you're trying to achieve?  Perhaps a better alternative
> >> can
> >> be suggested that doesn't break expected behaviour.
> >>
> > I'm investigating the use of Python as a grammar language. I'm trying
> > to achive minimal required syntax/verbage.
>
> Cool! You might take a look at http://spirit.sf.net for some ideas.
> Python's a great language for metaprogramming because of its rich
> syntax.  If you were willing to discourage left-recursion you might go
> with something like:
>
>   expression = term._('+').expression | term._('-').expression
>
> On the other hand, when I had to do something like this I built my own
> "python-like" syntax for the grammar rules and left the semantic
> actions in pure Python, then ran the files through a simple
> preprocessor.  It's just too ugly to write grammar rules in pure
> python without overloaded whitespace.
>
> --
> Dave Abrahams
> Boost Consulting
> www.boost-consulting.com

I'll look into it, thanks. But I had essentially come to the same
conclusion.

Bruce