Hi, I'd like to use the Control.Parallel.Strategies machinery to evaluate parts of a big record-based data structure in the background. The following code is the sort of thing that I've ended up with - it makes a spark that forces the actuals field of a user object, in the sense that it forces all of the elements to WHNF. (At least, that's what I hope it's doing!) updateActuals user = runEval $ do newActuals <- rparWith (evalTraversable rseq) $ calculateActuals user return user { actuals = newActuals } However, I'm concerned that runEval is marked as "for Strategy programmers" and that I should be using some collection of combinators instead of dropping down to this level. But I just can't work out how to combine the available combinators to do the same thing. In particular, all the articles I've found about this seem to end up adding `using` something to the end of one key line of code to achieve near-perfect parallelisation, but now that I come to do it myself I'm stuck! I think I'm looking for something like: updateActuals user = user { actuals = newActuals } `using` ... Can anyone help me fill in the blank there? Many thanks, David