On Wed, Jun 17, 2015 at 11:19 AM, Yusuke SUZUKI utatane@gmail.com
wrote:
It turns out the spec is fine
https://people.mozilla.org/~jorendorff/es6-draft.html#sec-weakmap.prototype.set
step 5 says
If Type
On 6/17/15 2:35 PM, Mark S. Miller wrote:
What do other browsers currently do?
Firefox:
var w = new WeakMap(); var r = Symbol.for('foo'); w.set(r, true);
TypeError: r is not a non-null object
WebKit nightly:
var w = new WeakMap(); var r = Symbol.for('foo'); w.set(r, true);
TypeError:
actually I was surprised the apparently mentioned native behavior looked
too much like my Symbol based WeakMap partial poly:
```js
var WeakMap = WeakMap || (function (s) {'use strict';
function WeakMap() {
this[s] = Symbol('WeakMap');
}
WeakMap.prototype = {
'delete': function
It turns out the spec is fine
https://people.mozilla.org/~jorendorff/es6-draft.html#sec-weakmap.prototype.set
step 5 says
If Type
https://people.mozilla.org/~jorendorff/es6-draft.html#sec-ecmascript-data-types-and-values
(*key*) is not Object, throw a *TypeError* exception.
as I hoped
TypeError: Invalid value used as weak map key
Yes, already fixed on v8. Thanks.
On Wed, Jun 17, 2015 at 11:51 AM, Caitlin Potter caitpotte...@gmail.com
wrote:
The v8 bug referred to earlier in this thread was filed by Rick Waldron
and fixed back in March, I think engines are on the same
It would return a different object each time (for the same Symbol, like new
String) so it would not exhibit the problem of being observable.
On Jun 17, 2015, at 20:54, Jordan Harband ljh...@gmail.com wrote:
Could I not use `Object(Symbol.for('some global registry symbol'))` as a
`WeakMap`
On Wed, Jun 17, 2015 at 9:31 AM, Yusuke SUZUKI utatane@gmail.com
wrote:
On Thu, Jun 18, 2015 at 1:18 AM, Mark S. Miller erig...@google.com
wrote:
[+Allen]
Can registered Symbols be used as keys in WeakMaps? If so, we have a
fatal unauthorized communications channel that we need to fix
The v8 bug referred to earlier in this thread was filed by Rick Waldron and
fixed back in March, I think engines are on the same page with this — just FYI
On Jun 17, 2015, at 2:49 PM, Boris Zbarsky bzbar...@mit.edu wrote:
On 6/17/15 2:35 PM, Mark S. Miller wrote:
What do other browsers
uh ... never mind then, I don't even need to understand :D
Cheers
On Wed, Jun 17, 2015 at 7:51 PM, Caitlin Potter caitpotte...@gmail.com
wrote:
The v8 bug referred to earlier in this thread was filed by Rick Waldron
and fixed back in March, I think engines are on the same page with this —
Could I not use `Object(Symbol.for('some global registry symbol'))` as a
`WeakMap` key? That would return a realm-specific object, of course.
On Wed, Jun 17, 2015 at 10:19 AM, Benjamin Gruenbaum ing...@gmail.com
wrote:
congratulations and THANK YOU! I learned something important reading
your
Interning of a particular immutable-objects-with-identity in an interning
table can still safely be weakly interned, by marking that object, at
interning time, so all WeakMaps from then on hold it strongly
Oh cool, I didn't realize that. That is pretty neat :)
On Wed, Jun 17, 2015 at 10:54 PM,
On 6/17/15 1:54 PM, Jordan Harband wrote:
Could I not use `Object(Symbol.for('some global registry symbol'))` as a
`WeakMap` key? That would return a realm-specific object, of course.
Object(Symbol.for(x)) == Object(Symbol.for(x)) tests false. That's
because
The idea that (a shared Weak interning table of
immutable-objects-with-identity + WeakMaps makes gc observable) is not new.
The idea that (the shared interning tables of
immutable-objects-with-identity must therefore be strong) is not new.
What was new to me is the idea that
Interning of a
this is puzzling me too ... so I've got few cases
1. you want/need a one to many relations, Symbol as key, Array as value,
and you play with that Array values as needed per each Symbol used as key
in the very same WeakMap
2. you invert the logic and you have a WeakMap that checks per each
On Jun 17, 2015, at 9:18 AM, Mark S. Miller wrote:
[+Allen]
Can registered Symbols be used as keys in WeakMaps? If so, we have a fatal
unauthorized communications channel that we need to fix in the spec asap!
No, symbols are not objects and the keys of WeakMaps must be objects.
BTW,
congratulations and THANK YOU! I learned something important reading your
messages. The notion that we can preserve non-observability when making one
thing a WeakMap iff we make all other WeakMaps be strong for those same
objects is true, novel, and very surprising. I have been working on
I am curious about what these are? But regardless, I would expect there to
be examples where it would be useful if it weren't fatal. Regarding the
issues in this thread, it actually would be safe to allow unregistered
Symbols as keys. But unless these examples are tremendously compelling,
please
Hi Yusuke, congratulations and THANK YOU! I learned something important
reading your messages. The notion that we can preserve non-observability
when making one thing a WeakMap iff we make all other WeakMaps be strong
for those same objects is true, novel, and very surprising. I have been
working
Aren't WeakMap keys only objects?
On Jun 17, 2015, at 19:18, Mark S. Miller erig...@google.com wrote:
[+Allen]
Can registered Symbols be used as keys in WeakMaps? If so, we have a fatal
unauthorized communications channel that we need to fix in the spec asap!
On Thu, Jun 18, 2015 at 1:18 AM, Mark S. Miller erig...@google.com wrote:
[+Allen]
Can registered Symbols be used as keys in WeakMaps? If so, we have a fatal
unauthorized communications channel that we need to fix in the spec asap!
Why do registered Symbols appear? (oops, maybe I missed
On Wed, Jun 17, 2015 at 10:41 PM, Mark Miller erig...@gmail.com wrote:
Hi Yusuke, congratulations and THANK YOU! I learned something important
reading your messages. The notion that we can preserve non-observability
when making one thing a WeakMap iff we make all other WeakMaps be strong
for
[+Allen]
Can registered Symbols be used as keys in WeakMaps? If so, we have a fatal
unauthorized communications channel that we need to fix in the spec asap!
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Thanks. And sorry for the late reply.
On Wed, Jun 17, 2015 at 11:31 AM, Mark S. Miller erig...@google.com wrote:
Hi Yusuke, I am not sure I understood your message. Could you show some
example code that would observe the observable difference you have in mind?
On Tue, Jun 16, 2015 at 7:25
On Wed, Jun 17, 2015 at 2:29 PM, Yusuke SUZUKI utatane@gmail.com
wrote:
Thanks. And sorry for the late reply.
On Wed, Jun 17, 2015 at 11:31 AM, Mark S. Miller erig...@google.com
wrote:
Hi Yusuke, I am not sure I understood your message. Could you show some
example code that would
Hi Yusuke, I am not sure I understood your message. Could you show some
example code that would observe the observable difference you have in mind?
On Tue, Jun 16, 2015 at 7:25 PM, Yusuke SUZUKI utatane@gmail.com
wrote:
Hi forks,
In ES6 spec, template site objects are strongly
If WeakSets were iterable, then any such optimization would be observable
and therefore disallowed. It is precisely the unobservability of GC that
give us the freedom to engage in such transparent optimizations.
The platform can certainly provide itself with internal iterable
WeakSet-like
It’s not related to observability, this just isn’t used currently, and probably
wouldn’t be much of an improvement if it were. Creating the template callsites
themselves is pretty costly, and using weak references to the callsites would,
in the majority of cases, mean recreating them every time
Thanks. That is clarifying.
On Tue, Jun 16, 2015 at 8:12 PM, Caitlin Potter caitpotte...@gmail.com
wrote:
It’s not related to observability, this just isn’t used currently, and
probably wouldn’t be much of an improvement if it were. Creating the
template callsites themselves is pretty
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