cursor :: Txn -> Dbi -> RAcquire e Cur
cursor txn dbi = mkRAcquire open close
  where
    open  = io $ mdb_cursor_open txn dbi
    close = io . mdb_cursor_close
cursor :: Txn -> Dbi -> RAcquire e Cur
cursor txn dbi = mkRAcquire open close
  where
    open  = io $ mdb_cursor_open txn dbi
    close = io . mdb_cursor_close
cursor txn dbi = mkRAcquire open close
  where
    open  = io $ mdb_cursor_open txn dbi
    close = io . mdb_cursor_close