[Python-Dev] async/await in Python; v2 (original) (raw)

Victor Stinner victor.stinner at gmail.com
Wed Apr 22 22:46:56 CEST 2015

Greg Ewing <greg.ewing canterbury.ac.nz> writes:

I still don't like the idea of hijacking the generic term "coroutine" and using it to mean this particular type of object.

There are only two hard things in Computer Science: cache invalidation

and naming things.

-- Phil Karlton

:-)

When reviewing Yury's PEP, I read Wikipedia's article of Coroutine because I didn't know if a "coroutine" is something new in Python nor if it was well defined.

https://en.wikipedia.org/wiki/Coroutine

Answer: it's not new, and it's implemented in many languages, and it's well defined.

But coroutines are not always directly called "coroutines" in other programming languages.

Using a custom name like "cofunction" may confuse users coming from other programming languages. I prefer to keep "coroutine", but I agree that we should make some effort to define the different categories of "Python coroutines". Well, there are two kind kinds of coroutines:

(A) asyncio coroutine in Python 3.4: use yield from, yield denied, decorated with @asyncio.coroutine (B) PEP 492 coroutine in Python 3.5: use await, yield & yield from denied, function definition prefixed by "async"

Yury proposed "generator-based coroutine for the kind (A). Maybe not a great name, since we can learn in the PEP 492 that the kind (B) is also (internally) based on generators.

I don't think that we should use distinct names for the two kinds in common cases. But when we need to clearly use distinct names, I propose the following names:

Kind (A):

Kind (B):

Victor

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