Fasterer: Parallel assignment is slower

Parallel assignment is slower than sequential assignment.
Only got the low hanging fruit. There are some functions that
have multiple return values. Fixing this needs more refactoring.

app/controllers/todos_controller.rb

@@ -40,18 +40,21 @@ class TodosController < ApplicationController
         cookies[:mobile_url]= { :value => request.fullpath, :secure => SITE_CONFIG['secure_cookies']}
         determine_down_count
 
-        render :action => 'index'
+        render :action => 'index'.freeze
       end
       format.text  do
         # somehow passing Mime::TEXT using content_type to render does not work
-        headers['Content-Type']=Mime::TEXT.to_s
+        headers['Content-Type'.freeze]=Mime::TEXT.to_s
         render :content_type => Mime::TEXT
       end
       format.xml do
         @xml_todos = params[:limit_to_active_todos] ? @not_done_todos : @todos
         render :xml => @xml_todos.to_xml( *todo_xml_params )
       end
-      format.any(:rss, :atom) { @feed_title, @feed_description = 'Tracks Actions', "Actions for #{current_user.display_name}" }
+      format.any(:rss, :atom) do
+        @feed_title = 'Tracks Actions'.freeze
+        @feed_description = "Actions for #{current_user.display_name}"
+      end
       format.ics
     end
   end
@@ -156,7 +159,10 @@ class TodosController < ApplicationController
     p = Todos::TodoCreateParamsHelper.new(params, current_user)
     tag_list = p.tag_list
 
-    @not_done_todos, @build_todos, @todos, errors = [], [], [], []
+    @not_done_todos = []
+    @build_todos = []
+    @todos = []
+    errors = []
     @predecessor = nil
     validates = true
 
@@ -887,13 +893,15 @@ class TodosController < ApplicationController
     elsif params[:format].nil?
       # if no format is given, default to html
       # note that if url has ?format=m, we should not overwrite it here
-      request.format, params[:format] = :html, :html
+      request.format = :html
+      params[:format] = :html
     end
   end
 
   def set_format_for_tag_view(format)
     # tag name ends with .m, set format to :m en remove .m from name
-    request.format, params[:format] = format, format
+    request.format = format
+    params[:format] = format
     params[:name] = params[:name].chomp(".#{format.to_s}")
 end