AFAIK, there's not an easy way in Haskell to inspect at the type level what type a field has in a record.
What I mean is that that there doesn't seem to be a type family like
type FieldType :: Type -> Symbol -> Type
that we could invoke in ghci like
:kind! FieldType Person "age"
Why would I want this? For libraries like servant and rel8 that use parameterized records where the types of the fields vary heavily with the type parameter.
