Re: [PATCH] submodule--helper.c: add only-active to foreach

[Guillaume Galeazzi <guillaume.galeazzi@gmail.com>]

Hi Junio

> If iterating over only active ones is useful, surely it would also
> be useful to be able to iterate over only inactive ones, right?
> 
> So, before getting married too much to the use-case of "only active
> ones" and getting our eyes clouded from seeing a larger picture,
> let's see what other "traits" of submodules we can use to pick which
> ones to act on.
> 
> Are there attributes other than "is-active" that we may want to and
> can check about submodules?  There is is_submodule_populated() next
> to is_submodule_active(), which might be a candidate. IOW, what I am
> wondering is if it makes sense to extend this to
> 
> 	git submodule foreach --trait=is-active ...
> 	git submodule foreach --trait=!is-active ...
> 	git submodule foreach --trait=is-populated ...
> 
> to allow iterating only on submodules with/without given trait (I am
> not suggesting the actual option name, but merely making sure that
> 'is-active' is not anything special but one of the possibilities
> that can be used to limit the iteration using the same mechanism).

The idea that other candidate are possible seem good. But then users 
will need combination like is-active && !is-populated. We will end up 
implementing a complex code to filter based on expression which is IMHO 
overkill.

If is-populated is needed, that could be implemented this way:

         git submodule--helper --is-populated[=true|false]

this would allow combination with the is active filter and the
previous example would be

         git submodule--helper --is-active --is-populated=false <cmd>

Regards,
GG