Support async for and async with constructs using macros

[chrisrink10]

Fixes #1179
Fixes #1181

[ikappaki]

Hi @chrisrink10,

Both definitions look good. I've been using the following for async for, which seems simpler than using a loop. Is there a catch perhaps somewhere, in terms of coverage, expression or performance using a context manager?

(defmacro forasync
  [[var value] & body]
  `(let [~var ~value]
    (~'await (.__aenter__ ~var))
    (try
      ~@body
      (finally
        (~'await (.__aexit__ ~var nil nil nil))))))

Thanks

[chrisrink10]

Both definitions look good. I've been using the following for async for, which seems simpler than using a loop. Is there a catch perhaps somewhere, in terms of coverage, expression or performance using a context manager?

I thought you wanted to have the async for loop?

[ikappaki]

Both definitions look good. I've been using the following for async for, which seems simpler than using a loop. Is there a catch perhaps somewhere, in terms of coverage, expression or performance using a context manager?

I thought you wanted to have the async for loop?

Sorry, yes you're right, please ignore the above, that was a trivial async with impl.