[Python-ideas] Where-statement (Proposal for function expressions)

[Guido van Rossum]

On Sun, Jul 19, 2009 at 11:29 AM, Jan Kaliszewski<zuo at chopin.edu.pl> wrote:
> Guido van Rossum <guido at python.org> wrote:
>
>> The 'where' proposal actually looks nice to me. (Maybe I've been
>> studying functional languages too much lately :-). My biggest problem
>> with this concrete proposal is that 'where' means something completely
>> different in SQL (which I've also studied too much lately :-).
>>
>> However, I think we should focus on keeping the language stable rather
>> than keep tinkering with it. Let's help 3rd party developers port
>> their work to 3.1 rather than planning 3.1's obsolescence.
>
> I believe it's at the other 'end for stick' of development process and
> doesn't hurt 3.1 at all.

Actually, adding too many new features post 3.1 *could* hurt 3.1 -- it
could slow adoption because people might decide to wait for 3.2 which
they expect to be even better. Plus the implementation of 3.2 features
uses up energy that would be better spent elsewhere (the Python
community has a chronic shortage of hands to help with menial task
like porting 3rd party code to 3.1).

Another argument against new features is that the people who have the
hardest time moving to 3.1 are those who are most bothered by change
in general. If they view the language as "moving too fast" they might
decide to move to a language that moves more slowly, or just stick
with Python 2.4, which is nearly as bad.

A more cynical view (the like of which I've heard expressed about Perl
6) would be that python-ideas is where we keep those folks occupied
who love to argue about new features but are unlikely to contribute
anything... :-)

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)