Generics.MultiRec.HFunctor

The definition of functorial map.

Generic map

class HFunctor phi f where

Methods

hmapA :: Applicative a => (forall ix. phi ix -> r ix -> a (r' ix)) -> phi ix -> f r ix -> a (f r' ix)

Instances

HFunctor phi U

HFunctor phi (K x)

El phi xi => HFunctor phi (I xi)

(Constructor c, HFunctor phi f) => HFunctor phi (C c f)

(Traversable f, HFunctor phi g) => HFunctor phi (:.: f g)

HFunctor phi f => HFunctor phi (:>: f ix)

(HFunctor phi f, HFunctor phi g) => HFunctor phi (:*: f g)

(HFunctor phi f, HFunctor phi g) => HFunctor phi (:+: f g)

hmap :: HFunctor phi f => (forall ix. phi ix -> r ix -> r' ix) -> phi ix -> f r ix -> f r' ix

The function hmap takes a functor f. All the recursive instances in that functor are wrapped by an application of r. The argument to hmap takes a function that transformes r occurrences into r' occurrences, for every ix. In order to associate the index ix with the correct family phi, the argument to hmap is additionally parameterized by a witness of type phi ix.

hmapM :: (HFunctor phi f, Monad m) => (forall ix. phi ix -> r ix -> m (r' ix)) -> phi ix -> f r ix -> m (f r' ix)

Monadic version of hmap.