On Wed, Apr 16, 2014 at 12:37 AM, Mark S. Miller <erights@google.com> wrote: > Summing up, using an object as a key, in either a Map or a WeakMap, should > only depend on the same object identity as used by ===. There's no reason > to make an exception for WindowProxy, so don't. > These classes let you ask questions about identity that previously there was no way of asking. Specifically, they let you ask whether a given object has the same identity as another object at another time. The === operator only lets you ask identity questions of two objects at the same time. Saying "just use the existing notion of identity" doesn't help resolve the question. Adam > On Wed, Apr 16, 2014 at 3:16 AM, Toon Verwaest <verwaest@chromium.org>wrote: > >> >> >> From a use cases perspective, there is one issue: how does one attach >> state to a "web page"? >> > >> > >> > That's a slippery notion because sometimes |w| acts like the container >> and sometimes it acts like the thing contained. Sounds like a recipe for >> security vulnerabilities when the author and WeakMap disagree about whether >> they're talking about the container or the thing contained... >> >> If you want to associate state with a proxy, use a WeakMap. >> >> If you want to attach state to a specific window with all security >> checks, install a private symbol on the window itself. (Granted, this does >> not exist yet :-)). >> > > > > -- > Cheers, > --MarkM >
Received on Wednesday, 16 April 2014 13:51:43 UTC