lib/madvertise/ext/hash.rb in madvertise-ext-0.2.2 vs lib/madvertise/ext/hash.rb in madvertise-ext-0.3.0

@@ -10,11 +10,22 @@
       newval = newval.to_hash if newval.respond_to?(:to_hash)
       oldval.is_a?(Hash) && newval.is_a?(Hash) ? oldval.deep_merge(newval) : newval
     end
   end
 
-  # Recursively merge and replace +other_hash+ into +self.
+  # Recursively merge and replace +other_hash+ into +self+.
   def deep_merge!(other_hash)
     replace(deep_merge(other_hash))
+  end
+
+  # accumulate existing keys from +other_hash+ into +self+.
+  def delta_merge!(other_hash)
+    other_hash.each do |k,v|
+      if self.has_key?(k)
+        self[k] += v
+      else
+        self[k] = v
+      end
+    end
   end
 
 end