Your code is indented less than it might otherwise be indented, and you type fewer literal functions. Oh and there wasn't any mention of error handling so apparently there is nothing to help you when one of the calls in a twait block throws. I wonder how twait interacts with try/catch. If it's purely a CPS transform then yeah, you're just fucked on error handling.

mkevent is like creating a Deferred and twait is like creating a DeferredList and calling when/then on it with the remainder of the code after the twait block used as the callback. Conceptually this is a very specific and concrete subset of functionality that promises give you.

I was wondering the same thing. If the spec evolves tools to handle this stuff, thats one thing, and of course this could be an example solution, but right now I think the problem has a solution without adding extra keywords to the language.

I would've thought the same thing until I wrote substantial async code in JS and Python.

It's not that it doesn't work and you can't do it, it's that the code becomes a mess and their example gets at that. It probably doesn't seem like a big deal, but when you constantly have to pass around callbacks and chain requests together you get this feeling the code could look a lot cleaner than it is. You want asynchronous behavior but with synchronous syntax.

This isn't possible without adding something, and, having seen a lot of the solutions out there, it's nice to see someone take a stab at it by changing the language. The cost is huge (preprocessing, etc.), but, speaking from experience, the simplicity of the code you write might make the change worth it. You get the feeling in 5-10 years this will be a solved problem, but I'm not sure any of the solutions out there yet will be the accepted solution.