[Python-Dev] Re: API change in 2.2.1c1 (original) (raw)

Jeremy Hylton jeremy@zope.com
Wed, 20 Mar 2002 11:23:11 -0500

M.--

Sorry I didn't respond earlier. I've been nearly unable to send mail for the last week. (New office, new firewall, bad SMTP server :-).

I think the cell change is a pure bug fix. The VAR_HEAD was leftover from the days (perhaps just one day) when I thought that a cell would contain multiple pointers. The cell objects aren't documented (so far as I know) and are only used internally to implemented nested scopes.

I had originally thought that each scope with "cell variables" would store all the pointers in a single cell. That ended up being a bad idea, because a single escaping cell var would keep all the other objects in the cell alive. The one-object-per-cell model minimizes that amount of garbage kept alive by escaping variables.

Jeremy