graph representation of data structures in optimizer

Hi,

I'm interested in data representation and debug of optimizer routines.
Thus, I've changed the debug functions of allpaths.c to make a
graphviz-like output of RelOptInfo structure.

Any idea about this?
Is there some project or improvement like this?

Tanks,
Adriano Lange
C3SL/UFPR - www.c3sl.ufpr.br