Nested Scopes ... next tail recursion?

[Joshua Marshall]

Tim Peters <tim.one at home.com> wrote:
> [Ronald Legere]
>> ...
>> I wonder if there is any chance of getting tail recusion
>> handled properly in the future?

> Best guess is slim.  It's rarely requested, and AFAIK there are no active
> Python developers who program in a style helped by this gimmick.  If so, no
> current developer is likely to contribute such a patch.

> BTW, if A calls B calls B calls B blows up, part of "properly" in *Python*
> would likely include generating a traceback as if tail calls had not been
> optimized.  May not require a full stack frame for each level, but may
> require that *something* be tucked away at each level, and in that case it
> wouldn't be "proper" by your meaning.

I'd be content with a trace that reflects the proper tail recursion.
It would be something built into (bolted onto?) the semantics of the
language, backward incompatibly; it wouldn't just be an optimization.
Though I guess this would be a backwards incompatible change
regardless of tracebacks.

Although proper tail recursion in Python would bring a smile to my
face, I still can't bring myself to say it's a good idea.  In Python
3000 on the other hand...