Ormolu uses -- ^ style to annotate arguments of a data constructor

[mrkkrp]

Ormolu currently transforms this snippet

-- | Foo.
data Foo
  = Foo
      -- | Bar
      Char
      -- | Baz
      Int

into

-- | Foo.
data Foo
  = Foo
      Char
      -- ^ Bar
      Int
      -- ^ Baz

which seems to be at odds with how we format Haddocks in other contexts. The version with pipes (-- |) is accepted by the latest ghc-lib-parser and so it makes sense to migrate to that style someday.

[amesgen]

Just for the record:

-- | Foo.
data Foo
  = Foo
      -- | Bar
      Char
      -- | Baz
      Int

started to parse (in Haddock mode) with GHC 9.0.1. Hence, we probably only should change the style here when GHC <9.0 is not used that much, as making Haddock suddenly fail is probably a bad experience.

[mrkkrp]

Yeah, I think we should wait a little bit and change when 9.4 is out.