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Postings from December 2011
On Fri Dec 30 06:31:34 2011, dolmen wrote:
> Le Sam. Déc. 24 18:55:03 2011, sprout a écrit :
> >
> > I think this is a bug, in that mentioning a variable in a sub shouldnât
> > change whether $x has the only reference after â$x = sub{}â.
>
> Well, it does.
>
> In my use case, I use weaken on closures to break circular references
> (an object method that stores as a member a closure that references
> $self, and I want the closure to disappear when $self is not anymore
> referenced). This is quite common when working with AnyEvent.
>
> The bug I had in my code was that I did use weaken "as usual" on the
> sub. So my mistake was to do a weaken on something which was not a
> closure: there was no circular reference problem in the first place. I
> was trying to use 'weaken' to workaround a problem which didn't exist.
>
> To avoid such mistakes in the future, would it be possible to detect and
> report such cases of usage of weaken on non-closure subs?
But holding a weak reference to a non-closure sub is not necessarily a
bug. Weak references are not just for breaking circularities, you know.
:-) Sometimes they are useful for maintaining mappings between
references. See, e.g., Tie::RefHash::Weak.
>
> > It also causes the blessing bug in ticket #3306.
>
> Thanks for that reference. I submitted an idea on how to fix that one too.
>
> --
> Olivier
--
Father Chrysostomos
---
via perlbug: queue: perl5 status: open
https://rt.perl.org:443/rt3/Ticket/Display.html?id=106864
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