diff engine, help needed

lib/diff_engine.rb

@@ -0,0 +1,21 @@
+# This class is used to generate diffs, it will be consumed by the UI on 
+# on the client the displays diffs.
+#
+# Ruby has the diff/lcs engine that can do some of the work, the devil 
+#  is in the details
+
+class DiffEngine
+  
+  # generate an html friendly diff similar to the way Stack Exchange generate
+  #  html diffs
+  #
+  #  retruns: html containing decorations indicating the changes
+  def self.html_diff(html_before, html_after)
+  end
+
+  # same as html diff, except that it operates on markdown
+  #
+  # returns html containing decorated areas where diff happened
+  def self.markdown_diff(markdown_before, markdown_after)
+  end
+end