Gentoo Archives: gentoo-user

From: Neil Bothwick <neil@××××××××××.uk>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Portage 2.2
Date: Wed, 24 Jul 2013 13:20:27
Message-Id: 20130724142017.1ff14d7d@hactar.digimed.co.uk
In Reply to: Re: [gentoo-user] Portage 2.2 by Alan McKinnon
1 On Wed, 24 Jul 2013 12:46:59 +0200, Alan McKinnon wrote:
2
3 > > What does that mean? set1 and one of set2 or set 3? Or both set1 and
4 > > set2 or set3 only? I'm not sure how this would be useful but I can
5 > > certainly see how it would cause confusion and problems, but I hadn't
6 > > heard if it before.
7 > >
8 > >
9 >
10 > It's standard mathematical set operators. In maths, a set is defined as
11 > "a collection of well-defined objects". Sets have no dupes.
12 >
13 > http://en.wikipedia.org/wiki/Set_%28mathematics%29
14 > http://en.wikipedia.org/wiki/Set_theory
15 >
16 > Sets have several well-defined operations that can be done on them:
17 > union, intersection, difference plus a few others.
18 >
19 > @set1+@set2/@set3 reduces to:
20 >
21 > all the elements of set1 and set2 without the elements that are in set3
22 > (/ is difference).
23 >
24 > As an example, assume portage ships two sets @kde and @kdedev:
25 >
26 > @kde
27 > kdeadmin-meta
28 > kdebase-meta
29 > kdemultimedia-meta
30 > kdepim-meta
31 > ...
32 >
33 > @kdedev
34 > kdewebdev-meta
35 > kdebindings-meta
36 > kdesdk-meta
37 >
38 >
39 > However, kmail sucks and akonadi sucks moar, so define for yourself
40 >
41 > @suckykde
42 > kdepim-meta
43 >
44 > And add to your world sets:
45 >
46 > @kde+@kdedev/@suckykde
47 >
48
49 I see, what about operator precedence, is that equivalent to
50
51 (@kde+@kdedev)/@kdesuckykde or @kde+(@kdedev/@kdesuckykde)
52
53 It's been a long time since I studied set operators at Uni :(
54
55
56 --
57 Neil Bothwick
58
59 I cna ytpe 300 wrods pre mniuet!!!

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Re: [gentoo-user] Portage 2.2 Alan McKinnon <alan.mckinnon@×××××.com>