+getPageA :: ArrowIO a => Storage -> a (PageName, Maybe RevNum) (Maybe Page)
+getPageA = arrIO2 . getPage
+
+
+putPageA :: ArrowIO a => Storage -> a (Page, RevNum) ()
+putPageA = arrIO2 . putPage
+
+
+searchPages :: MonadIO m => Storage -> Condition -> m [(PageName, RevNum)]
+searchPages sto cond
+ = liftIO $
+ do var <- newEmptyTMVarIO
+ atomically $ writeTChan (stoIndexChan sto) (SearchIndex cond var)
+ atomically $ takeTMVar var
+