How hard will it be to make your patch compatible with the current stylish-haskell head (which supports ghc 9.2)? If it's not so hard, could you also send a PR there?

How hard will it be to make your patch compatible with the current stylish-haskell head (which supports ghc 9.2)? If it's not so hard, could you also send a PR there?

Not easy, I developed based on v0.13.0.0, which has a bunch of different representations, current head has a clean structure with ghc9.2. I'd prefer someone can send this fork to hackage directly and this fork should exist as a branch in haskell/stylish-haskell, because it's just a compat that only works for HLS(Others will choose v0.14 ideally)

Let's take a step back:

• Stylish-haskell uses ghc-lib so it's not directly coupled to the ghc version. Concretely, stylish-haskell-0.13 uses ghc-lib-parser-8.10 and stylish-haskell-0.14 uses ghc-lib-parser-9.2
• Moreover, other HLS plugins also have ghc-lib-parser requirements. Concretely, hlint-3.3.6 requires ghc-lib-9.0 and hlint-3.2.8 requires ghc-lib-parser-8.10.
• ghc-lib-parser versions have ghc requirements themselves. From the project readme:

What this means for HLS

• ghc 8.10.7 We can fallback to hlint-3.2.8 and stylish-haskell-0.13 which both accept ghc-lib-parser-8.10.7
• ghc 9.0 Since ghc-lib-parser-8.10.7 doesn't build with ghc 9.0, we cannot use hlint-3.2.8 nor stylish-haskell-0.13 anymore. We have to choose between hlint-3.3.6 and stylish-haskell-0.14
• ghc 9.2 Since ghc-lib-parser-9.0 doesn't build with ghc 9.2, we cannot use hlint-3.3.6. But stylish-haskell-0.14 is fine.

The future-proof and non-forky thing to do here is to evolve hlint to support ghc 9.2. Once that's available, we can link both stylish-haskell and hlint in all the ghc versions from 8.10.7.

That said, I am not against merging this PR, as it doesn't make anything worse and it means that we can distribute 9.0 binaries which support both plugins.

Relevant hlint issue: ndmitchell/hlint#1359

It's worth closing this and waiting for hlint support before the next hls release.