[Zope-dev] ZCML implementations: where should they go

[Dieter Maurer]

Jim Fulton wrote at 2009-2-10 14:01 -0500:
>
>On Feb 10, 2009, at 1:49 PM, Dieter Maurer wrote:
>
>> Jim Fulton wrote at 2009-2-8 13:00 -0500:
>>> ...
>>> IMO, introducing an extra is like introducing a new package and in a
>>> rather complicated way.
>>
>> I agree with the first part of your sentence -- but cannot follow you
>> with the second part:
>>
>>  How can "'extra' : <sequence of required distributions>"
>>  be more complicated than creating, maintaining and
>>  distributing a complete package?
>
>
>Because you have to remember to test each valid permutation of the  
>package.  I bet no one does.

But that is the same when each extra is represented by an individual
package. Then, too, you have to test each valid combination -- and
few will do it.

> Also, users have to be aware of the  
>extras. PyPI doesn't advertise extras

I am interested in extras only when I am interested in the package
itself. Of course, the package should document in some way
relevant extras.

>nor are there standard ways to  
>document them.

I recently looked at documentation for a few "standard" packages
on PyPI -- and apart from all using "rest" and a bit of
classifiction, I could not detect much "standard" for them, too.


>In general, it makes an already complicated packaging  
>system more complicated.

That's something I do not get...

An extra is a shorthand for a separate package with a few extra dependancies.

Sure, shorthands are not strictly necessary.
Sure, complexity increases slightly.
Nevertheless, they are often valuable.



-- 
Dieter