[Python-Dev] Accessing globals without dict lookup (original) (raw)

Tim Peters tim.one@comcast.net
Tue, 12 Feb 2002 15:24:47 -0500

[Fred]

Have we become convinced that these cells need to be Python objects?

No, it's just easier that way. The existing dict code maps PyObject* to PyObject*, so we'd have to copy and fiddle all of the dict code if a celldict wants to map to anything other than a PyObject*.

I must have missed that. As long as we can keep them simple structures, we should be able to avoid individual allocations for them. It seems we have a fixed number of cells for both module objects and function objects (regardless of whether they are part of the new celldict or the containing function or module), so they can be allocated as an array rather than individually.

So, I must be missing something.

cells don't live in function objects; a function object only has a vector of pointers to cells, and that is indeed a contiguous, fixed-size array.

cells are the values in celldicts, and that's the only place they appear, and celldicts can grow dynamically (import fred; fred.brandnew = 1).