a little optimization

src/Affection/Particle.hs

@@ -117,8 +117,10 @@ updateParticleSystem
   -> Affection us ParticleSystem
 updateParticleSystem sys sec upd draw = do
   x <- catMaybes <$> mapM (updateParticle sec upd) (partStorList $ partSysParts sys)
+  -- liftIO $ traceIO $ show $ length x
   -- x <- catMaybes <$> foldM (updateParticle sec upd) [] (reverse $ psParts sys)
-  when (not $ null x) $ do
+  if (not $ null x)
+    then do
       -- liftIO $ G.gegl_node_link_many $ map particleStackCont (partStorList $ partSysParts sys)
       -- liftIO $ traceIO "linking last node to output"
       liftIO $ G.gegl_node_link (particleStackCont $ head x) (partSysNode sys)
@@ -132,6 +134,8 @@ updateParticleSystem sys sec upd draw = do
               else partStorLatest (partSysParts sys)
           }
         }
+    else
+      return sys
 
 -- | Function for inserting a new 'Particle' into its 'PartileSystem'
 insertParticle