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Subject: Re: [PHP-DEV] RFC WeakRefs
From: rowan.collins@gmail.com (Rowan Collins)

On 17 May 2018 10:35:11 BST, Etienne Kneuss <colder@php=2Enet> wrote:
>That said, if the plan is to subsume pecl-weakref, I suggest we also
>reimplement weakmaps, which offer a convenient way of storing
>meta/cache
>data and is not implementable in userland without trade-offs=2E

It looks to me like WeakMap would be fairly trivial to implement in userla=
nd as a combination of WeakRef, ArrayAccess, Iterable, and an internal SplO=
bjectStorage for the ability to use objects as keys (although I'm not clear=
 why it uses object keys in the first place)=2E

The only part that seems hard to write efficiently is Countable support, s=
ince you'd have to iterate the internal hash checking for unset objects=2E =
I suppose iteration would also slow down a bit of lots of the references we=
re now unset=2E Is that the trade-off you're referring to, that the C imple=
mentation has some magic to avoid?

Regards,

--=20
Rowan Collins
[IMSoP]