Cloning WeakSet/WeakMap

Hi.

I was asked to include a way to clone WeakSet in Set builtins proposal. Is
there any consensus on security of such operation?

Michał Wadas
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Hi,

My understanding is that cloning a WeakSet into a Set would remove all its
properties related to security and garbage collection.

The properties related to security and garbage collection of WeakSet are
based on the fact that its elements are not enumerable by someone who would
only be holding a reference to the WeakSet. If you want to "clone" a
WeakSet into a Set it means you have an expectation that the set of
elements are deterministically enumerable.

WeakSets and Sets, despite there close name and API, are used in different
circumstances.

David


2018-02-09 9:53 GMT-05:00 Michał Wadas <michalwadas at gmail.com>:

> Hi.
>
> I was asked to include a way to clone WeakSet in Set builtins proposal. Is
> there any consensus on security of such operation?
>
> Michał Wadas
>
> _______________________________________________
> es-discuss mailing list
> es-discuss at mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
>
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I think this is referring to cloning a WeakSet into another WeakSet

Thomas Grainger

On 9 February 2018 at 15:01, David Bruant <bruant.d at gmail.com> wrote:

> Hi,
>
> My understanding is that cloning a WeakSet into a Set would remove all its
> properties related to security and garbage collection.
>
> The properties related to security and garbage collection of WeakSet are
> based on the fact that its elements are not enumerable by someone who would
> only be holding a reference to the WeakSet. If you want to "clone" a
> WeakSet into a Set it means you have an expectation that the set of
> elements are deterministically enumerable.
>
> WeakSets and Sets, despite there close name and API, are used in different
> circumstances.
>
> David
>
>
> 2018-02-09 9:53 GMT-05:00 Michał Wadas <michalwadas at gmail.com>:
>
>> Hi.
>>
>> I was asked to include a way to clone WeakSet in Set builtins proposal.
>> Is there any consensus on security of such operation?
>>
>> Michał Wadas
>>
>> _______________________________________________
>> es-discuss mailing list
>> es-discuss at mozilla.org
>> https://mail.mozilla.org/listinfo/es-discuss
>>
>>
>
> _______________________________________________
> es-discuss mailing list
> es-discuss at mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
>
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English isn't my native language, so I probably made a mistake.

I was asked to add WeakSet.prototype.union(iterable) creating new WeakSet
instance including data from both iterable and original WeakSet.



On 9 Feb 2018 4:01 pm, "David Bruant" <bruant.d at gmail.com> wrote:

> Hi,
>
> My understanding is that cloning a WeakSet into a Set would remove all its
> properties related to security and garbage collection.
>
> The properties related to security and garbage collection of WeakSet are
> based on the fact that its elements are not enumerable by someone who would
> only be holding a reference to the WeakSet. If you want to "clone" a
> WeakSet into a Set it means you have an expectation that the set of
> elements are deterministically enumerable.
>
> WeakSets and Sets, despite there close name and API, are used in different
> circumstances.
>
> David
>
>
> 2018-02-09 9:53 GMT-05:00 Michał Wadas <michalwadas at gmail.com>:
>
>> Hi.
>>
>> I was asked to include a way to clone WeakSet in Set builtins proposal.
>> Is there any consensus on security of such operation?
>>
>> Michał Wadas
>>
>> _______________________________________________
>> es-discuss mailing list
>> es-discuss at mozilla.org
>> https://mail.mozilla.org/listinfo/es-discuss
>>
>>
>
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2018-02-09 10:05 GMT-05:00 Michał Wadas <michalwadas at gmail.com>:

> English isn't my native language, so I probably made a mistake.
>
oh ok, sorry for my misinterpretation


> I was asked to add WeakSet.prototype.union(iterable) creating new WeakSet
> instance including data from both iterable and original WeakSet.
>
ok, I don't have an opinion on this idea

David


>
>
>
> On 9 Feb 2018 4:01 pm, "David Bruant" <bruant.d at gmail.com> wrote:
>
>> Hi,
>>
>> My understanding is that cloning a WeakSet into a Set would remove all
>> its properties related to security and garbage collection.
>>
>> The properties related to security and garbage collection of WeakSet are
>> based on the fact that its elements are not enumerable by someone who would
>> only be holding a reference to the WeakSet. If you want to "clone" a
>> WeakSet into a Set it means you have an expectation that the set of
>> elements are deterministically enumerable.
>>
>> WeakSets and Sets, despite there close name and API, are used in
>> different circumstances.
>>
>> David
>>
>>
>> 2018-02-09 9:53 GMT-05:00 Michał Wadas <michalwadas at gmail.com>:
>>
>>> Hi.
>>>
>>> I was asked to include a way to clone WeakSet in Set builtins proposal.
>>> Is there any consensus on security of such operation?
>>>
>>> Michał Wadas
>>>
>>> _______________________________________________
>>> es-discuss mailing list
>>> es-discuss at mozilla.org
>>> https://mail.mozilla.org/listinfo/es-discuss
>>>
>>>
>>
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Possibly a silly question, but...

What happens re garbage collection if you have two WeakSets referencing the
same object? Do they each block that object's removal?

On Fri, 9 Feb 2018 at 15:05 Michał Wadas <michalwadas at gmail.com> wrote:

> English isn't my native language, so I probably made a mistake.
>
> I was asked to add WeakSet.prototype.union(iterable) creating new WeakSet
> instance including data from both iterable and original WeakSet.
>
>
>
> On 9 Feb 2018 4:01 pm, "David Bruant" <bruant.d at gmail.com> wrote:
>
>> Hi,
>>
>> My understanding is that cloning a WeakSet into a Set would remove all
>> its properties related to security and garbage collection.
>>
>> The properties related to security and garbage collection of WeakSet are
>> based on the fact that its elements are not enumerable by someone who would
>> only be holding a reference to the WeakSet. If you want to "clone" a
>> WeakSet into a Set it means you have an expectation that the set of
>> elements are deterministically enumerable.
>>
>> WeakSets and Sets, despite there close name and API, are used in
>> different circumstances.
>>
>> David
>>
>>
>> 2018-02-09 9:53 GMT-05:00 Michał Wadas <michalwadas at gmail.com>:
>>
>>> Hi.
>>>
>>> I was asked to include a way to clone WeakSet in Set builtins proposal.
>>> Is there any consensus on security of such operation?
>>>
>>> Michał Wadas
>>>
>>> _______________________________________________
>>> es-discuss mailing list
>>> es-discuss at mozilla.org
>>> https://mail.mozilla.org/listinfo/es-discuss
>>>
>>>
>> _______________________________________________
> es-discuss mailing list
> es-discuss at mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
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Why would they? You can put single object in *infinite* amount of WeakSets
and it won't prevent it's garbage collection.

On 9 Feb 2018 4:11 pm, "Michael Luder-Rosefield" <rosyatrandom at gmail.com>
wrote:

> Possibly a silly question, but...
>
> What happens re garbage collection if you have two WeakSets referencing
> the same object? Do they each block that object's removal?
>
> On Fri, 9 Feb 2018 at 15:05 Michał Wadas <michalwadas at gmail.com> wrote:
>
>> English isn't my native language, so I probably made a mistake.
>>
>> I was asked to add WeakSet.prototype.union(iterable) creating new
>> WeakSet instance including data from both iterable and original WeakSet.
>>
>>
>>
>> On 9 Feb 2018 4:01 pm, "David Bruant" <bruant.d at gmail.com> wrote:
>>
>>> Hi,
>>>
>>> My understanding is that cloning a WeakSet into a Set would remove all
>>> its properties related to security and garbage collection.
>>>
>>> The properties related to security and garbage collection of WeakSet are
>>> based on the fact that its elements are not enumerable by someone who would
>>> only be holding a reference to the WeakSet. If you want to "clone" a
>>> WeakSet into a Set it means you have an expectation that the set of
>>> elements are deterministically enumerable.
>>>
>>> WeakSets and Sets, despite there close name and API, are used in
>>> different circumstances.
>>>
>>> David
>>>
>>>
>>> 2018-02-09 9:53 GMT-05:00 Michał Wadas <michalwadas at gmail.com>:
>>>
>>>> Hi.
>>>>
>>>> I was asked to include a way to clone WeakSet in Set builtins proposal.
>>>> Is there any consensus on security of such operation?
>>>>
>>>> Michał Wadas
>>>>
>>>> _______________________________________________
>>>> es-discuss mailing list
>>>> es-discuss at mozilla.org
>>>> https://mail.mozilla.org/listinfo/es-discuss
>>>>
>>>>
>>> _______________________________________________
>> es-discuss mailing list
>> es-discuss at mozilla.org
>> https://mail.mozilla.org/listinfo/es-discuss
>>
>
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