1 files changed, 31 insertions, 6 deletions
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index ee9bd36f6..ffb71bb44 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -116,9 +116,7 @@ class Formula
   #   }
   # The final option is to return DATA, then put a diff after __END__. You
   # can still return a Hash with DATA as the value for a patch level key.
-  def patches; end
-  # reimplement and specify dependencies
-  def deps; end
+  def patches; [] end
   # sometimes the clean process breaks things, return true to skip anything
   def skip_clean? path; false end
   # rarely, you don't want your library symlinked into the main prefix
@@ -129,7 +127,7 @@ class Formula
   def brew
     validate_variable :name
     validate_variable :version
-    
+
     stage do
       begin
         patch
@@ -165,6 +163,7 @@ class Formula
   end
 
   def self.factory name
+    return name if name.kind_of? Formula
     path = Pathname.new(name)
     if path.absolute?
       require name
@@ -181,6 +180,10 @@ class Formula
     HOMEBREW_PREFIX+'Library'+'Formula'+"#{name.downcase}.rb"
   end
 
+  def deps
+    self.class.deps or []
+  end
+
 protected
   # Pretty titles the command and buffers stdout/stderr
   # Throws if there's an error
@@ -327,9 +330,31 @@ private
   end
 
   class <<self
-    attr_reader :url, :version, :homepage, :head
+    attr_reader :url, :version, :homepage, :head, :deps
     attr_reader *CHECKSUM_TYPES
-  end
+
+    def depends_on name, *args
+      @deps ||= []
+
+      case name
+      when String
+        # noop
+      when Hash
+        name = name.keys.first # indeed, we only support one mapping
+      when Symbol
+        name = name.to_s
+      when Formula
+        @deps << name
+        return # we trust formula dev to not dupe their own instantiations
+      else
+        raise "Unsupported type #{name.class}"
+      end
+
+      # we get duplicates because every new fork of this process repeats this
+      # step for some reason I am not sure about
+      @deps << name unless @deps.include? name
+    end
+  end  
 end
 
 # see ack.rb for an example usage