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authorZac Medico <zmedico@gentoo.org>2010-09-02 23:21:06 -0700
committerZac Medico <zmedico@gentoo.org>2010-09-02 23:21:06 -0700
commit1f920fdc717beb939e4e225173c17a1aa7bc63be (patch)
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Add a "Delayed Evaluation of Disjunctive Dependency Choices" section
to depenency resolution documentation.
-rw-r--r--doc/dependency_resolution/decision_making.docbook13
1 files changed, 13 insertions, 0 deletions
diff --git a/doc/dependency_resolution/decision_making.docbook b/doc/dependency_resolution/decision_making.docbook
index ffb1a4ab2..d64ff83f6 100644
--- a/doc/dependency_resolution/decision_making.docbook
+++ b/doc/dependency_resolution/decision_making.docbook
@@ -9,6 +9,19 @@
represents one possible alternative combination of dependency
atoms capable of satisfying the dependency expression.
</para>
+ <sect2 id='dependency-resolution-decision-making-dependency-expression-evaluation-delayed-disjunction'>
+ <title>Delayed Evaluation of Disjunctive Dependency Choices</title>
+ <para>
+ Disjunctive dependencies, of which virtuals are a special case,
+ can be satsified by multiple choices of dependency atoms. These
+ choices are delayed until as late as possible in the dependency
+ calculation, after packages have been selected to satisfy
+ as many non-disjunctive dependencies as possible. As a consequence
+ of this delayed evaluation, there is maximal information available
+ which makes it possible to optimize choices such that the total
+ number of packages required to satisfy all dependencies is minimized.
+ </para>
+ </sect2>
</sect1>
<sect1 id='dependency-resolution-decision-making-look-ahead'>
<title>Look-Ahead</title>