Re: [gentoo-dev] GLEP 29 (USE Flag Grouping) with -@GROUP goodness

[Maurice van der Pot]

On Mon, Oct 25, 2004 at 03:02:08AM +0200, Marius Mauch wrote:
> On 10/24/04  Ed Grimm wrote:
>
> > How about the following:
> >
> > We add a + operator, to specify settings which are fundamentally part
> > of the group.  Negating the group strips all negations, strips all
> > simply present flags, and negates those with a +.

Ed, that's a good idea. I'd go with this instead of adding some new 
character to indicate a dependency.

> Please lets try to keep this as simple as possible. Personally I don't
> see what's wrong with a simple string expansion with the optional
> negation modifier. True, this might create results in some situations
> that are confusing at first view, but at least it's easy to explain,
> every more complicated proposal will also create (other) potentially
> confusing results and will be harder to explain.
So in your view, what Ed and I are suggesting is more complex than the
original proposal? I definitely disagree on that. The implementation of
what I proposed is simple to implement (handle a group at a time, automatically
making circular references impossible), simple to debug (groups do not 
influence eachother unless one lists the other, evaluation is not order 
dependent) and simple to use (if a user doesn't think about it a lot, 
it will still have the expected results in cases like @KDE -@GNOME).


> And keep in mind: more
> complexity results in longer implementation times (well, design +
> implementation + testing + documentation).

This code is preprocessing for a set of use flags. Once the preprocessing
is done, you will have a final set of use flags that will be used like
USE= is now. It doesn't get much easier to test than that.

Maurice.

-- 
Maurice van der Pot

Gentoo Linux Developer   griffon26@g.o     http://www.gentoo.org
Creator of BiteMe!       griffon26@××××××××.com   http://www.kfk4ever.com