Yep, I'm using something very like this in a Node project I'm working on. However, with(context) has some pretty nasty side effects that I just couldn't sidestep, so I used the "contextify" module.
If you're needing with and have access to npm, use contextify, It'll save you a lot of effort!
Thanks for the tip, but I'm far from working with javascript right now[1], I was barely trying to understand the trick. I love the fact that this 'app' is a 6x6 variables grid layout javascript editor in disguise.
[1] I just finished skimming through eloquent js and js allonge, and this still eluded me.
If you're needing with and have access to npm, use contextify, It'll save you a lot of effort!