Bind kind variables in type synonyms
I wonder if GHC could support the binding of kind-variables in type-synonyms (I am using standalone kind signatures):
type F :: forall a (b :: a -> Type). a -> Type type F @_ @f x = f x
or even (still new to VDQ):
type F :: forall a. forall (b :: a -> Type) -> a -> Type type F @_ f x = f x
This would mirror the term-level after proposals like Binding type variables in lambda-expressions are implemented.