July 26, 2012 TC39 Meeting Notes

Tom Van Cutsem tomvc.be at gmail.com
Wed Aug 1 05:51:02 PDT 2012


2012/7/31 Brandon Benvie <brandon at brandonbenvie.com>

> It's definitely a concern of my that proxies have the necessary tools to
> allow for fully wrapping arbitrary object graphs. Is there any case where
> not being able to trap private names would prevent that goal?


Well, yes if:
1) proxies wouldn't be able to trap private names, and
2) the private name is accessible to both sides of the membrane,
then the private name could be used to pierce the membrane.

The current consensus is that proxies should trap private names, so 1) is
false.

I've been thinking some more about whether we could prevent 2), but the
more I think about it, the more it seems to me that private name values,
though modeled as (immutable) objects, should be treated by membranes as
primitive data and should be passed through unmodified (like numbers and
strings). It doesn't make sense for a membrane to wrap a private name,
since the only important thing about a private name is its (object)
identity, and you lose that by wrapping. A wrapped private name would be
useless.

This strengthens the argument that proxies should be able to trap private
names.

Cheers,
Tom
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