Co-routines (as of JavaScript 1.7)

So I was playing around with some of the new features in JavaScript 1.7 - not a lot of discussion about them in the Firefox 2.0/IE 7 release brouhaha, but definitely really useful improvements there for developers.

In particular, co-routines (in the form of the "yield" operator) are the key big improvement (IMHO). The rest is mostly syntactic sugar - and in fact, most of those are indeed enabled by co-routines (which they label as "Generators").

I have to admit, though, to being a little disappointed with trying to use them in practice, for "programming in the large" with JS type things. As always, I might be missing something - but what I'm finding is that most of the time I don't want to necessarily yield to just the calling function; I want to yield waaaay up the stack. I think what I'm really looking for is a "resumable" exception of sorts- where I can yield all the way up somewhere, take some action, and then continue execution back to the yield - ALMOST there with JS 1.7 generators - but the implementation seems to be more about keeping up with Python superficially... ah, well.

Still - it does simplify A LOT of real world design patterns, so I can't complain. No denying that co-routines are a powerful programming paradigm, which I first saw in Ruby, then Python, and now JavaScript. There are even a few attempts to bring them to C - but I guess the interesting question will be how much browser adoption (in a fragmented market) of these features affects their real world utility and use.

Adobe has much less of that particular adoption problem - being a single vendor monopoly for core technology has its advantages.