[Python-Dev] Re: tp_clear return value

Neil Schemenauer nas@python.ca
Wed, 9 Apr 2003 15:48:10 -0400

On Wed, Apr 09, 2003 at 03:33:47PM -0400, Jeremy Hylton wrote:
> Why does tp_clear have a return value?  All the code I've seen returns
> 0, but the only place that clear is called doesn't inspect its return
> value.

I guess I would have to say overdesign.  I was thinking that tp_clear
and tp_traverse could somehow be used by things other than the GC.  In
retrospect that doesn't seem likely or even possible.  The GC has pretty
specific requirements.

In retrospect, I think both tp_traverse and tp_clear should have
returned "void".  That would have made implementing those methods
easier.  Testing for errors in tp_traverse methods is silly since
nothing returns an error, and, even if it did, the GC couldn't handle


How do we sort this out?  I suppose one step would be to document that
the return values of tp_traverse and tp_clear are ignored.  If we agree
on that, I volunteer to go through the code and remove the useless tests
for errors in the tp_traverse methods.