[Python-ideas] Proposal: Moratorium on Python language changes

geremy condra debatem1 at gmail.com
Wed Oct 21 22:00:54 CEST 2009

On Wed, Oct 21, 2009 at 3:02 PM, Guido van Rossum <guido at python.org> wrote:
> On Wed, Oct 21, 2009 at 11:52 AM, geremy condra <debatem1 at gmail.com> wrote:
>> Towards that end, I'd also like to propose a very public, very
>> accessible 'sandbox' specifically for the development and testing of
>> new language features while the moratorium is in effect. Its goal
>> would be to keep interest in changes to core language design
>> ongoing by keeping the barrier to entry low, while simultaneously
>> separating it from core development. With any luck, it would mean
>> that when the moratorium lifts, Python will be able to take its pick
>> from the best of the language proposals, while still having given
>> other implementations the opportunity to study their behavior
>> "in the wild" for a period of months or years.
> I can't stop people from forking the language to do experiments, but
> one of the goals I have for the moratorium is actually to *reduce* the
> interest in core language changes, and to *raise* the barrier to
> entry. Most language change proposals are just fluff, and they will be
> just as unneeded three years from now as they are today. Once the
> moratorium is lifted, users should be able expect the normal, slow,
> conservative evolution of the language to continue -- not to see the
> floodgates lifted for a barrage of new features.
> --
> --Guido van Rossum (home page: http://www.python.org/~guido/)

Granted that most language change proposals could only be
described as "terrible" by a person of unusual charity, but if
the goal here isn't to permanently forbid all changes, then it
makes sense (to me) to ensure that we're in a better position
when we leave the moratorium than when we go into it.

Right now, the barrier for proposing a language change is
pretty much nonexistent- you dreamed it up in the shower,
read about it in a trade magazine, your dog told you it was
a good idea, doesn't matter- put it on python-ideas. The
problem (as I see it) is that after proposing the idea,
wasting a lot of time, and causing a lot of drama, the fact
remains that even if the OP finally gets their way, the odds
are good that it will take a substantial amount of work from
people who have better things to do- the core developers-
to make it work. And it only gets worse for the other
implementors, who probably didn't have as much input in
the process as the CPython devs did.

Changing the way that core language changes are proposed
and evaluated changes that a lot, though. In the scenario
I've proposed, we are in effect saying "write the code and
if it gets a lot of support we'll talk about including it in a few
years". It shifts the responsibility for development from the
core dev team to the one proposing the change. I'm
confident that that alone would cut out most of the proposals
on python-ideas, while ensuring that whatever was up for
consideration at the point where the moratorium lifts
was high-quality, well thought out code that had probably
been looked at pretty closely by other implementors for
several years. Personally, I think that's a much better
place to be than either where we are now or where
we'll be in a few years without some sort of brainstorm

Geremy Condra

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