[scialex]

Thanks.

I believe HKT would have been useful but am not really sure how much HKT would have helped me overall. They would likely have been most useful (if at all) in the VFS/S5FS/VM stages that I was unable to fully get to.

Honestly, I have not used haskell enough to definitively say whether monads/arrows would have been useful.

[mafribe]

I guess the only way to find out is to await the emergence of low-level languages with HKTs and then run suitable experiments.