[Web-SIG] PEP 444 / WSGI 2 Async

[Alice Bevan–McGregor]

On 2011-01-07 13:21:36 -0800, Antoine Pitrou said:
> Ok, so, WSGI doesn't "already involve generators". QED.

This can go around in circles; by allowing all forms of iterable, it 
involves generators.  Geneators are a type of iterable.  QED right 
back.  ;)

>>> Right, that's why I was suggesting you drop your concern for Python 2 
>>> compatibility.
>> 
>> -1
>> 
>> There is practically no reason for doing so;
> 
> Of course, there is one: a less complex PEP without any superfluous 
> compatibility language sprinkled all over.

There isn't any "compatibility language" sprinkled within the PEP.  In 
fact, the only mention of it is in the introduction (stating that < 2.6 
support may be possible but is undefined) and the title of a section 
"Python Cross-Version Compatibility".

Using native strings where possible encourages compatibility, though 
for the environ variables previously mentioned (URI, etc.) explicit 
exceptional behaviour is clearly defined.  (Byte strings and true 
unicode.)

> Just because you "managed to write" some piece of code for a 
> *particular* use case doesn't mean that cross-compatibility is a solved 
> problem.

The particular use case happens to be PEP 444 as implemented using an 
async and multi-process (some day multi-threaded) HTTP server, so I'm 
not quite sure what you're getting at, here.  I think that use case is 
sufficiently broad to be able to make claims about the ease of 
implementing PEP 444 in a compatible way.

> If you think it's easy, then I'm sure the authors of various 3rd-party 
> libs would welcome your help achieving it.

I helped proof a book about Python 3 compatibility and am giving a 
presentation in March that contains information on Python 3 
compatibility from the viewpoint of implementing the Marrow suite.

>> Python 2.x will be around for a long time.
> 
> And so will PEP 3333 and even PEP 333. People who value legacy 
> compatibility will favour these old PEPs over your new one anyway. 
> People who don't will progressively jump to 3.x.

Yup.  Not sure how this is really an issue.  PEP 444 is the /future/, 
333[3] is /now/ [-ish].

	- Alice.