Refcount vs GC semantics (was RE: [Python-Dev] Product iteration)

[Tim Peters]

Plea:  could we try to get an accurate subject line on at least 1 msg in 10?
Thanks.

[Moshe]
> I know, and I'm not. But the thing is, there are plenty of users of
> CPython which do rely on this feature -- so you're going to break
> people's code. Not nice.

[Mark Hammond]
> No - we will simply be pointing out their already broken code.  We
> arent breaking anything!
>
> I have no problem with this at all.  The sooner we point out the
> broken code the better.  The last thing we want is for obviously and
> documented broken code to suddenly be considered non-broken simply by
> the volume of poor code out there...

Spoken like a man who has never maintained a language implementation used by
hordes of unhappy users <0.5 wink>.  The bitching about "breaking"
.append(1,2,3) was nothing compared to what this would stir up, and when the
first "important" customer seriously threatens to walk, vendors usually back
down out of a healthy sense of self-preservation.  Been there so many times
it even makes me want to puke <wink>.

> Either way, I think you are overstating the problem.

I agree with that too.  I don't think CPython could get away with this, but
you have a new implementation and users will see this as a basis on which
they compete.  The *convenience* of CPython's (accidental but real!)
semantics here is undeniable.  Still, I don't see it coming up much except
wrt temp files, and if that becomes An Issue for you, you can always
special-case the snot out of them.

users-don't-read-manuals-but-they-do-pay-the-bills-ly y'rs  - tim