[Distutils] Static metadata using setup.cfg

[Tarek Ziadé]

On Wed, Sep 9, 2009 at 1:31 AM, Greg Ewing<greg.ewing at canterbury.ac.nz> wrote:
> Tarek Ziadé wrote:
>
>> In that case, if we want to keep a configparser-compatible file, we
>> need to find another
>> way to express these if/else parts, which will probably lead to a
>> complex, non natural
>> syntax.
>
> Maybe the conditions could be expressed in the
> section headers?
>
> [requires platform="linux"]
> ...
>
> [requires platform="win32"]:
> ...
>
> Then it's not so much if-then-else logic as just
> tagging parts of the file with conditions under
> which they apply.

The problem is that we need more complex conditions like:
"platform == linux and python >= 2.5"

in that case, the ConfigParser format is making it hard to do it
like you've described, unless the section is the full expression :

[requires platform="linux" and python >="2.5"]

Notice that this *does* work with ConfigParser but you can't express
'else' conditions easily. But this is not a great deal, I can accomodate not
having elses.

Maybe the expression can be located in a specific variable for readability:

"""
[setup]
name = foo
conditional-sections = one, two

[one]
condition: platform="linux" and python >= "2.5"
require: lxml

[two]
condition: platform="win32" and python >= "2.5"
require: docutils
"""

This would be more powerfull since each section could define any metadata,
under some conditions.

I would be ok with that shape, even if I do find this more readable:

"""
[setup]
name = foo

{$ if platform="linux" and python >= "2.5": $}
require: lxml
{$ :endif $}

{$ platform="win32" and python >= "2.5": $)
require: docutils
{$ :endif $}
"""

In any case, the restrictions to what variables the expressions can
work with would stay the same.

>
> --
> Greg
> _______________________________________________
> Distutils-SIG maillist  -  Distutils-SIG at python.org
> http://mail.python.org/mailman/listinfo/distutils-sig
>



-- 
Tarek Ziadé | http://ziade.org | オープンソースの岩！