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On Sun, Oct 24, 2004 at 06:10:12PM +0100, Ciaran McCreesh wrote: |
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> On Sun, 24 Oct 2004 18:31:19 +0200 Maurice van der Pot |
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> | Whether a use flag is specifically turned off for a group or it is |
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> | just not present in the group should make no difference for the |
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> | meaning of GROUP. The same holds for -@GROUP. In other words, -use and |
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> | -@GROUP should only be used in the definition of a group to filter |
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> | flags out. |
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> | |
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> | Assume MYGNOME="@GNOME -gtk", then USE="... -@MYGNOME ..." should |
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> | *not* be equivalent to USE="... -@GNOME gtk ...", instead it should |
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> | not influence the state of gtk at all. |
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> |
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> Interesting idea. This then brings us back to one of the original |
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> objections, which was that there should be some way to turn off flags |
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> from within a group. Only way to do that would be to introduce yet |
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> another modifier, which is inconsistent with the rest of portage and |
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> will confuse the heck out of anyone who hasn't studied set theory... |
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I just now read the comments to the previous edition. I should've done |
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that sooner. |
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What I see is that people want to be able to use -@GROUP, which is perfectly |
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understandable. The actual behaviour of -@GROUP in my proposal is imho quite |
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a bit more intuitive. It wouldn't have to be discouraged. |
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I also read that some people only saw the need for negative use flags in |
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case the use flags themselves are expressed as a negation (nojoystick). |
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I haven't been involved enough with these things to see if there really |
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is a good reason to have those kinds of use flags at all. |
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If there isn't, then the definition that I prefer for -flag is "exclude flag |
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from this group" and that is both sufficient and easily understandable. |
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The people who do not understand the exact meaning of all this would |
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still be able to use -@GROUP in their use flags and it would work as |
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they would expect. |
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> | I would specify it like this: |
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> | |
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> | KDE $X kde qt -gtk -gnome |
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> | GNOME $X gtk gtk2 gnome -kde -qt |
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> | |
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> | USE="@KDE @GNOME" |
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> | |
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> | That would result in: |
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> | USE="X kde qt gtk gtk2 gnome" |
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> | |
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> | Exactly what the user wants. |
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> |
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> Hm. Although, I don't think "I want KDE" should imply "I don't want |
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> GNOME" anyway... |
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Right. It's just that even with screwy group definitions, there's still |
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a good chance that the result is fine. It's easier to debug if the -flags |
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don't carry over to other groups. |
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It should be reasonably simple to write an interpreter for these flags |
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and groups. Unfortunately I don't know python, but I'd be willing to |
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make an implementation in C or something if that would help. |
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Can anyone see any disadvantages of this method? |
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Let me know what you think. |
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Maurice. |
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-- |
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Maurice van der Pot |
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|
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Gentoo Linux Developer griffon26@g.o http://www.gentoo.org |
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Creator of BiteMe! griffon26@××××××××.com http://www.kfk4ever.com |
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