[Python-3000] PEP3100 update: chained exceptions

[Guido van Rossum]

On 4/24/06, Aahz <aahz at pythoncraft.com> wrote:
> The recent discussion about the with statement on python-dev reminded me
> that at one point we talked about making chained exceptions automatic.
> Could someone update PEP3100 to list chained exceptions as one of the
> features that needs discussion?

It's not mentioned there now, is it? (If it is, I can't find it so a
hint on the line number would be appreciated. :-)

IMNSHO this feature (PEP 344) is dead unless someone can find a way
around the excessive circular references involving locals that this
feature will necessarily cause. (And no, handwaving solutions are not
accepted -- you need to understand the cause of the circularities in
the proposal and explain a detailed plan for getting rid of them.
Relying on GC is unacceptable because of the effect on local variables
-- while reference counting is technically a CPython implementation
detail, many people have come to rely on the predictable finalization
semantics and I don't want to brfeak this wholesale. We had this in
early Python versions and it was a big pain.)

--
--Guido van Rossum (home page: http://www.python.org/~guido/)