The default instantiation of @'Control.Monad.State.Class.MonadState' ('Dao.Tree.Tree' 'Dao.String.Name' 'Dao.Object.Object) ('Dao.Predicate.PTrans' 'Dao.Struct.UpdateErr' ('Control.Monad.State.State' ('Dao.Tree.Tree' 'Dao.String.Name' 'Dao.Object.Object'))) was causing an infinite loop, I had to explicitly instantiate it. I also found that there are still some bugs in the "Dao.Struct" module. I fixed one in the 'Dao.Struct.atAddress' function (which required adding the 'Dao.Tree.insertNode' function into the "Dao.Tree" module), but it is still not working correctly.
The "Dao.Prelude" module is still a work in progress, but it is already quite nice, with many useful functions and instantiations. I had to modify the "Main" module of the test program to make use of functions that have been recently been moved to "Dao.Prelude".