[Haskell-cafe] Monad transformers [Stacking monads]

[Anton van Straaten]

Andrew Coppin wrote:
>> If so, I guess that means I have to somehow construct ResultSetT. Is 
>> there an easy way to do that, given that I already have ResultSet? 

I haven't been following this thread closely, so forgive if this was 
already discussed, but my understanding is that the answer is no, in 
general.

In the paper "Monad Transformers and Modular Interpreters"[*], Section 8 
("Lifting Operations") touches on some of the issues.  That's from 1995 
- I don't know if any progress on this has been made since then, other 
than that a standard set of the most common monad transformers is now 
available.

Anton

[*] http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.17.268