> Even Bartosz said that Adjoints aren't that interesting in Haskell because every functor is an endofunctor. Every functor (in the standard library) is an end

> Even Bartosz said that Adjoints aren't that interesting in Haskell because every functor is an endofunctor. Every functor (in the standard library) is an endofunctor, but is also a functor to a specific flavor of full subcategory in Hask. It might be useful to support other flavors of subcategory, and I think there's some ongoing work on this in the SubHask module.