How does the addition of Backpack to GHC 8.2 impact the design and development of HaLVM. I believe the HaLVM is currently using the HALVMInterfaces library to mimick something like Ocaml’s modules. But the addition of Backpack can offer a different approach to modularizing in HaLVM.
We’re planning to use Backpack as one of the core technologies in HaLVM 3.0, for exactly the reason you suggest. The idea is to create Backpack interfaces for key underlying subsystems, which allows programmers to write against generic interfaces that can then be reified to particular operating systems and implementations.
See, for example, these signatures on the wip-halvm3-base-backpack branch: