Hello all, I was asking this question on #haskell and thoughtpolice directed me here for a possibly more up-to-date information. Some of the important primitives offered by Data Parallel Haskell are reduction primitives such as sumP and prodP, which take a data parallel array and reduce it to a single value. I was wondering what the current capabilities for end-users interested in implementing their own reduction primitives were. In particular, if I want to run data parallel computations on strings, I will generally want a more exotic set of combining operators. thoughtpolice informed me that GHC 6.10 seemed to have sumP/prodP hard coded into the vectorisation and optimisation stages, so this didn't really seem possible in userspace. I'm interested to know if this situation has changed. No hard feelings if it hasn't; I'm really just playing around with DPH and seeing what it can do. :-) Cheers, Edward