From:  Paul Bone <pbone@mozilla.com>
Date:  06 Jun 2018 08:32:49 Hong Kong Time
Newsgroup:  news.mozilla.org/mozilla.dev.tech.js-engine.internals
Subject:  

Re: Same-compartment realms

NNTP-Posting-Host:  63.245.214.181

On Tue, Jun 05, 2018 at 09:26:58AM +0200, Jan de Mooij wrote:
> On Tue, Jun 5, 2018 at 7:50 AM, Paul Bone  wrote:
> 
> > Could you explain (or point me to an explaination) of what Realms are for?
> > I've gathered that they're a TC39 thing that's being added, maybe for
> > security? but since they don't restrict references between realms the way
> > compartments and CCWs do, maybe I'm mistaken?  Why add them?
> >
> > I expect the answer is in one of the references or almost-common knowledge,
> > but I seem to have missed it, sorry.
> >
> 
> Realms are a TC39 thing, but they're not new - a "realm" is just a global
> object and things associated with it (for instance, each global object has
> its own copy of Object.prototype and other builtin functions and
> prototypes). See https://tc39.github.io/ecma262/#sec-code-realms
> 
> So if you have a website with 10