Le 27/11/2013 19:14, Rick Waldron a écrit :
> # Nov 19 Meeting Notes
>
> ## 4.4 Finalizing the Proxy API for ES6
> (Presented by Tom Van Cutsem)
>
> (...)
>
> DS: What is typeof and instanceof
>
> AWB/BE: object
>
> BE: Capital P
>
> AWB: Ca???
>
> DS: Whatever Proxy creates?
>
> BE: That depends on what is created.
>
> DS: By default?
>
> BE: typeof depends if there is a call trap. instanceof depends on the 
> prototype chain. All in the spec, so can create any object (apart from 
> private state issues)
Shouldn't it depend on the target's typeof value? depending on apply 
(not call) trap makes typeof unstable ("delete handler.apply").
In any case, extra caution is required to keep typeof stability for 
revokable proxies (on revocation, maybe the value need to be saved 
somewhere)

nit:
"instanceof depends on the prototype chain"
=> Note that it calls the getPrototypeOf trap which doesn't enforce 
anything for extensible objects [1], so "*the* prototype chain" has a 
more volatile meaning for proxies than it has for regular objects.

David

[1] https://mail.mozilla.org/pipermail/es-discuss/2013-September/033370.html

Le 27/11/2013 19:14, Rick Waldron a écrit :
> # Nov 19 Meeting Notes
>
> ## 4.4 Finalizing the Proxy API for ES6
> (Presented by Tom Van Cutsem)
>
> (...)
>
> DS: What is typeof and instanceof
>
> AWB/BE: object
>
> BE: Capital P
>
> AWB: Ca???
>
> DS: Whatever Proxy creates?
>
> BE: That depends on what is created.
>
> DS: By default?
>
> BE: typeof depends if there is a call trap. instanceof depends on the 
> prototype chain. All in the spec, so can create any object (apart from 
> private state issues)

Shouldn't it depend on the target's typeof value? depending on apply 
(not call) trap makes typeof unstable ("delete handler.apply").
In any case, extra caution is required to keep typeof stability for 
revokable proxies (on revocation, maybe the value need to be saved 
somewhere)

nit:
"instanceof depends on the prototype chain"
=> Note that it calls the getPrototypeOf trap which doesn't enforce anything for extensible objects [1], so "*the* prototype chain" has a more volatile meaning for proxies than it has for regular objects.

[1]: https://mail.mozilla.org/pipermail/es-discuss/2013-September/033370.html