Daniel Dunbar firstname.lastname@example.org writes:
Lazily tracking the tuples seems to be a much simpler proposition
This proposal sounds good, but there are a few issues.
and PyTuple_SET_ITEM and PyTuple_SetItem are modified
This is a problem: PyTuple_SET_ITEM is compiled into the extension module, so you need to bump the API version (or else old modules would be used that do not have your change).
In theory if v is a tuple, _SetItem(o,i,v) should only be called when v has been completely filled, so if v is untracked then we know it also cannot be member of a cycle, which solves the nested tuple problem.
I think it is safe to make this assumption. The worst case is that you get cyclic garbage that won't be collected. Given that it is a bug to refer to an "incomplete" tuple, I think this consequence of this bug is acceptable.
A 2.23 patch for the changes outlined above are at: http://www.geocities.com/evilzr/lazytuplegc/ (I wasn't sure if such things are appropriate for the SF-patch manager - yes/no?)
If you think this patch is reasonably complete, and you wish that it is included in Python, then yes, put it onto SF.