{-# LANGUAGE AllowAmbiguousTypes #-} module Pandora.Paradigm.Structure.Ability.Focusable where import Pandora.Pattern.Category ((.)) import Pandora.Pattern.Functor.Covariant (comap) import Pandora.Pattern.Functor.Extractable (extract) import Pandora.Paradigm.Inventory.Optics (type (:-.)) import Pandora.Paradigm.Primary.Functor.Tagged (Tagged (Tag)) class Focusable f t where type Focusing (f :: * -> k) (t :: * -> *) a focusing :: Tagged f (t a) :-. Focusing f t a focus :: forall f t a . Focusable f t => t a :-. Focusing f t a focus :: t a :-. Focusing f t a focus = (Tagged f (t a) -> t a) -> Store (Focusing f t a) (Tagged f (t a)) -> Store (Focusing f t a) (t a) forall (t :: * -> *) a b. Covariant t => (a -> b) -> t a -> t b comap Tagged f (t a) -> t a forall (t :: * -> *) a. Extractable t => a <:= t extract (Store (Focusing f t a) (Tagged f (t a)) -> Store (Focusing f t a) (t a)) -> (t a -> Store (Focusing f t a) (Tagged f (t a))) -> t a :-. Focusing f t a forall (m :: * -> * -> *) b c a. Category m => m b c -> m a b -> m a c . Tagged f (t a) :-. Focusing f t a forall k (f :: * -> k) (t :: * -> *) a. Focusable f t => Tagged f (t a) :-. Focusing f t a focusing (Tagged f (t a) :-. Focusing f t a) -> (t a -> Tagged f (t a)) -> t a -> Store (Focusing f t a) (Tagged f (t a)) forall (m :: * -> * -> *) b c a. Category m => m b c -> m a b -> m a c . forall a. a -> Tagged f a forall k (tag :: k) a. a -> Tagged tag a Tag @f data Location a = Root a | Head a