Transition to EIO and Cstruct

[vog]

I'd like to make these great ZStandard binding more suitable to modern OCaml 5 development. In particular, I'd like to change the following details of the current implementation:

• Remove dependency on the Core library
• Transfer data between C and OCaml via Cstruct rather than Bigarray
• Add facilities for direct usage via Eio.Flow (perhaps via a second package for OCaml 4 compatibility, and to not enforce EIO dependencies on everyone using this library)

In preparation, I would like to have your advice on this:

• Do you think the above changes make sense and would be an improvement to the library?
• Does it make sense to strive for backwards compatibility, and if so, would you accept such deep changes (given interface backwards compatibility) as a Pull Request?
• Or would you rather recommend a fork on this library? Or some way in between?

[vog]

Do you have any opinion / advice for me?

[lpw25]

I'm not one of the maintainers of this specific library, but I think we aren't likely to want to move in this direction. We prefer using Bigarray directly rather than using cstruct, and over time I expect us to move towards using slice types based on some of our ongoing OxCaml work instead. We don't use eio and don't intend to, although we do plan to build on top of something along the lines of Picos, which should allow interoperability with eio.

I could be missing something, but I would have thought you could write a shallow wrapper around this library that presented the API that you want. I think that is probably a better direction to go in.