[xml-bindings]Proposal 2: __eq__ for Python node wrappers

[Marc-Antoine Parent <maparent acm org>]

Another extension proposal: I often try to ascertain whether any two 
nodes or even sometimes documents are identical. However, I cannot rely 
on object equality, and not even on object equality of the underlying 
PyCObject which may be different for the same node. (Solving the latter 
is of course beyond the scope of this list, but I assume that I can 
somehow access the PyCObject's pointer to the underlying pure C object 
if I were to implement __eq__ in C.)

I suppose that changing __eq__ would also make it desirable to 
implement a __hash__ method, based on the C object's pointer's 
position; __ne__ is of course necessary.

Again, would that be considered a good thing?

(If so, we could even consider going further: Would we want to 
implement a full __cmp__? For nodes within a document, it could be 
defined by depth-first ordering, but that is much more difficult. It 
also leaves open the question of what to do for nodes of different 
documents... I guess that would have to rely on an ordering between 
documents, which could only be arbitrary. But I am much less certain 
that this is a good idea.)

Marc-Antoine