Dependency.expand_dependencies

Move Formula.expand_dependencies into the Dependency class, and extend
it to allow arbitrary filters to be applied when enumerating deps.

When supplied with a block, expand_dependencies will yield a [dependent,
dependency] pair for each dependency, allowing callers to filter out
dependencies that may not be applicable or useful in a given situation.

Deps can be skipped by simple calling Dependency.prune in the block,
e.g.:

  Dependency.expand_dependencies do |f, dep|
    Dependency.prune if dep.to_formula.installed?
  end

The return value of the method is the filtered list.

If no block is supplied, a default filter that omits optional or
recommended deps based on what the dependent formula has requested is
applied.

Formula#recursive_dependencies is now implemented on top of this,
allowing FormulaInstaller to exact detailed control over what deps are
installed. `brew missing` and `brew upgrade` can learn to use this to
apply the installed options set when expanding dependencies.

Move Formula.expand_deps and Formula#recursive_deps into compat, because
these methods do not respect the new optional and recommended tags and
thus should no longer be used.

1 files changed, 15 insertions, 0 deletions

diff --git a/Library/Homebrew/compat/compatibility.rb b/Library/Homebrew/compat/compatibility.rb
index f0d6ab0b1..67f540844 100644
--- a/Library/Homebrew/compat/compatibility.rb
+++ b/Library/Homebrew/compat/compatibility.rb
@@ -99,6 +99,21 @@ class Formula
       val.nil? ? @bottle_sha1 : @bottle_sha1 = val
     end
   end
+
+  # These methods return lists of Formula objects.
+  # They are eprecated in favor of Dependency::expand_dependencies
+  # and Formula#recursive_dependencies, which return lists of
+  # Dependency objects instead.
+  def self.expand_deps f
+    f.deps.map do |dep|
+      f_dep = Formula.factory dep.to_s
+      expand_deps(f_dep) << f_dep
+    end
+  end
+
+  def recursive_deps
+    Formula.expand_deps(self).flatten.uniq
+  end
 end
 
 class UnidentifiedFormula < Formula