On Wed, Apr 16, 2014 at 10:13 AM, Adam Barth <abarth@chromium.org> wrote: > On Wed, Apr 16, 2014 at 6:57 AM, Domenic Denicola < > domenic@domenicdenicola.com> wrote: > >> Let’s put it this way; perhaps what Mark’s saying will be clearer. >> >> Given: >> >> ```js >> const m = new Map(); >> m.set(windowProxyInstance, "foo"); >> ``` >> >> (and given that nothing else is added to `m`), then `m.get(x) === "foo"` >> should be true _if and only if_ SameValueZero(x, windowProxyInstance) is >> true (which in this case reduces to `x === windowProxyInstance`). >> >> Window proxies should do nothing to violate this invariant of `Map`s. >> >> With that in mind, is there something special about window proxies that >> would allow them to abide by this invariant but still run into the >> questions and problems stated in this thread? >> > > Presumably you would agree that if I wrote: > > windowProxyInstance = someOtherObject; > > then operator=== questions about windowProxyInstance wouldn't be relevant > for answering questions about how m.get behaves. > > One way of phrasing the original question is asking whether navigating a > browsing context keeps the identity of the windowProxyInstance constant or > whether the identity of the windowProxyInstance changes and all fields > containing a reference to the previous windowProxyInstance are updated to > refer to the new windowProxyInstance. > > I don't believe there's an experiment you can run today in browsers to > answer that question. Map would give you a way to answer that question, > which is why we need to decide what the answer ought to be. > I tried the code example (with typos fixed) from the original post in Firefox and Chrome (with experimental JS turned on) before posting my original reponse ( https://dl.dropboxusercontent.com/u/3531958/windowproxy/index.html). Both browsers produced the same result: "hello". Is there something missing there? Rick
Received on Wednesday, 16 April 2014 15:35:05 UTC