[Python-ideas] gevent-like Coroutines in Python

[Ron Reiter]

One of Golang's advantages is that goroutines act like gevent's coroutines
instead of relying on an async/await syntax. In my opinion, it makes Golang
code much more readable.

I feel like having the await syntax trigger by default on any awaitable
invocation in a coroutine context makes much more sense. I consider
async/await syntax to be too complicated for the average developer since it
opens up too many abilities whereas most developers would always mean they
prefer to do this:

result = [await fun(x) for fun in funcs]

versus:

result = [fun(x) for fun in funcs]
await asyncio.gather(*result)

Moreso, having it become the default makes statements like this:

result = [await fun(x) for fun in funcs if await smth]

Look like this:

result = [fun(x) for fun in funcs if smth]

Therefore, my suggestion is to create a new "async" definition which
basically turns every function invocation into an "await" if a generator is
returned. Instead of "async def" I propose the alternative "coroutine def"
syntax. However, a better solution may be to imply the word "async" in
every function definition given some sort of trigger (however I assume that
this won't be the preferable approach as it is not something that can be
implemented at the parsing level).

For me, I believe that Python should aspire to be both concise and
straightforward, which means no boilerplate code just because it's more
"correct" but rather assume there's some logical default behavior going on
in the back - and to me this logical behavior is that every invocation can
trigger an await and go back to the main loop. Our assumption that a
function invocation has to tie back to instant execution unless an "await"
statement has been placed should be challenged in favor of readability,
conciseness, and to always aim to appeal to novice developers (which I
believe is the reason Python is on such a rise these days).

I do have to admit I have not thought through what is the best syntax or
the implications of this because I would like to see what is the general
opinion on this idea first.

- Ron
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-ideas/attachments/20181030/f5a0dddf/attachment-0001.html>