On Wed, 24 Jul 2013 12:46:59 +0200, Alan McKinnon wrote: > > What does that mean? set1 and one of set2 or set 3? Or both set1 and > > set2 or set3 only? I'm not sure how this would be useful but I can > > certainly see how it would cause confusion and problems, but I hadn't > > heard if it before. > > > > > > It's standard mathematical set operators. In maths, a set is defined as > "a collection of well-defined objects". Sets have no dupes. > > http://en.wikipedia.org/wiki/Set_%28mathematics%29 > http://en.wikipedia.org/wiki/Set_theory > > Sets have several well-defined operations that can be done on them: > union, intersection, difference plus a few others. > > @set1+@set2/@set3 reduces to: > > all the elements of set1 and set2 without the elements that are in set3 > (/ is difference). > > As an example, assume portage ships two sets @kde and @kdedev: > > @kde > kdeadmin-meta > kdebase-meta > kdemultimedia-meta > kdepim-meta > ... > > @kdedev > kdewebdev-meta > kdebindings-meta > kdesdk-meta > > > However, kmail sucks and akonadi sucks moar, so define for yourself > > @suckykde > kdepim-meta > > And add to your world sets: > > @kde+@kdedev/@suckykde >
I see, what about operator precedence, is that equivalent to (@kde+@kdedev)/@kdesuckykde or @kde+(@kdedev/@kdesuckykde) It's been a long time since I studied set operators at Uni :( -- Neil Bothwick I cna ytpe 300 wrods pre mniuet!!!
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