@hackage parametric-functor0.1.0.0

A known-parametric Functor typeclass

As Oleg Grenrus argued in 2019, Functors should be parametric, and in particular should:

  • Satisfy fmap coerce = coerce

  • Have a ∀ a b. Coercible a b ⇒ Coercible (f a) (f b) super-constraint

Until this change gets adopted in base, this package can be used for a variant of Functor which satisfies these requirements.