really-small-backpack-example VS macaroni.nix

Isn’t this what Haskell’s backpack does? https://github.com/danidiaz/really-small-backpack-example

Also worth mention how module identity works in Backapck: two modules instantiated separately but with the same ingredients are "equal" and have compatible types.

Anyway, an alternative to RULES that I've explored is to put the proofs behind a module signature and compile to versions of the program, one with "real" proofs and another with unsafeCoerced ones. This avoids the danger of the RULEs silently ceasing to apply because of name changes (don't know how common is that danger in practice though).

Here's an example of how to use Backpack (instead of rewrite rules) to alternate between "normal" proofs and the ones which use usafeCoerce.

Perhaps Backpack could enable something similar to that?

While being nowhere near programmability, Cabal's common stanzas can be very useful to reduce duplication. An example.

In addition, I am building a Nix library on top of haskell.nix called macaroni.nix that is gamedev-oriented and enables seamless cross-compiling from Linux to Windows. I would say it's the best option for Windows Haskell game x-compilation available today.

We just managed to get our ludum dare game finished, including standalone builds (with a very special thanks to macaroni.dev.) The game is a platformer written in sdl and yampa, with build scripts for releasing static linux and windows builds.

Aside from that, haskell/macaroni.nix make x-compilation work great. I even was able to use the h-raylib bindings with little upstream changes/overlays.

In terms of finished and playable games, it's been Ludum Dare jam games made over a weekend over the years. You can check them out here. They're all Windows-only (x-compiled from NixOS using haskell.nix via macaroni.nix), but you can play them on Linux with Wine64. If you have Nix installed, I have a script that should Just Work.

Also feel free to cut me an issue in my related project, macaroni.nix. The project is focused on x-compiling Haskell games and only supported Windows currently. But brick is a viable gamedev library, and Raspberry Pi is a desired target for gamedev someday. So I'd love to help!