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On Fri, 25 Jul 2014 16:46:07 -0500 |
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William Hubbs <williamh@g.o> wrote: |
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> On Fri, Jul 25, 2014 at 10:25:57PM +0100, Ciaran McCreesh wrote: |
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> > On Fri, 25 Jul 2014 16:23:23 -0500 |
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> > William Hubbs <williamh@g.o> wrote: |
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> > > I think this could get complicated really quick though. |
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> > > For example, if I have an ebuild with three use flags, |
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> > > flag1/flag2/flag3 with the requirement that one and only one of |
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> > > them must be set, unless bash has an xor operator I don't know |
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> > > about, that is going to need a lot of nesting etc to get right. |
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> > |
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> > You don't want xor. You want addition. |
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> |
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> Can you show an example? |
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Well, if the use flag is on, you count it as 1, and if it's off, you |
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count it as 0. Then "need at least one" is just "the sum of these values |
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is at least 1", and "need exactly one" is "the sum of these values is |
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exactly 1". |
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-- |
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Ciaran McCreesh |
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