Commits on Jun 18, 2024

1. Give Compose's instances explicit kind signatures …

   Previously, the promoted versions of certain `Compose` instances (`Functor`,
   `Foldable`, etc.) would be overly general due to the fact that `singletons-th`
   omits instance contexts during promotion. For example, the promoted `Functor`
   instance for `Compose` was:
   
   ```hs
   instance PFunctor (Compose (f :: k -> Type) (g :: Type -> k)) where ...
   ```
   
   But this was too general, as `f` and `g` should both be of kind `Type -> Type`
   instead. The defunctionalization symbols associated with the instances also had
   a similar problem.
   
   This patch annotates each instance with an explicit kind (e.g., `Functor
   (Compose (f :: Type -> Type) g)` to ensure that the promoted instances also
   have the intended kind. This is very much in the same spirit as the situation
   described in `Note [Using standalone kind signatures not present in the base
   library]` in `Control.Monad.Singletons.Internal`, but for instance declarations
   instead of class declarations.
   
   Resolves the "Overly polymorphic instance methods" section of #601.

   

   RyanGlScott committed Jun 18, 2024
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