Python 2 namespace change? (was Re: [Python-Dev] Changing existing class instances)

[Jim Fulton]

Tim Peters wrote:
> 
> [Jim Fulton]
> > ...
> > A change to the way that namespaces are handled
> > could make this work and have a number of other benefits,
> > like global name usage without namespace lookups.
> >
> > I've suggested this to Guido in the past.  His
> > reasonable response is that this would be too big a
> > change for Python 1. Maybe this is something to consider
> > for Python 2?
> >
> > The basic idea (borrowed from Smalltalk) is to have a kind
> > of dictionary that is a collection of "association"
> > objects.  An association object is simply a pairing of a
> > name with a value. Association objects can be shared among
> > multiple namespaces.
> 
> Jim, I've been intrigued by this idea for all the years you've been
> suggesting it <wink>, but I've never understood what it is you're proposing!
> This is the Python-Dev list, so feel encouraged to present it in concrete
> implementation terms instead of ambiguous English.  Or maybe an interface?
> 
> interface a_kind_of_dictionary_that_is_a_collection_of_\
>               association_objects:
>     # ??? beats me ...
> 
> Or maybe as a C struct?  For example, is "an association object" a (char*,
> PyObject*) pair?

I just responded to Guido in a bit more detail. Hopefully, this will
be of sufficient clarity. If not, then I'll be happy to work up
a Python demonstration.

> Does this kind of dictionary have keys? 

Yes.

> If so, of what type? 

Whatever you want. Just like a dictionary.

> What type are
> the values? 

ditto.

> Best I can make sense of the above, the values are "association
> objects", each of which contains a name and a value, and a key is maybe a
> duplicate of the name in the association object to which it maps.  "A name"
> may or may not be a string -- I can't tell. 

Sorry. See my reply to Guido and let me know if I'm still being
too vague.

> Or maybe by "dictionary" you
> didn't intend Python's current meaning for that word at all.  I assume "a
> value" is a PyObject*.  The whole thrust *appears* to be to get names to map
> to a PyObject** instead of PyObject*, but if that's the ticket I don't know
> what association objeects have to do with it.
> 
> > An import like:
> >
> >   from foo import spam
> >
> > would copy the association between the name 'foo' and a
> > value from module 'spam' into the current module.
> 
> Where does the idea that 'spam' is a *module* here come from? 

From my lack of careful typing. Sorry. let me try again:

An import like:

   from foo import spam

would copy the association between the name 'spam' and a
value from module 'foo' into the current module.

Jim

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