flatten package:relational-query

flatten :: (ProjectableFlattenMaybe a b, ProjectableMaybe p) => p a -> p b

relational-query Database.Relational.Arrow Database.Relational.Projectable

flattenMaybe :: ProjectableMaybe p => p (Maybe (Maybe a)) -> p (Maybe a)

relational-query Database.Relational.Arrow Database.Relational.Projectable

Compose nested Maybe phantom type on record.

flattenPiMaybe :: (PersistableWidth a, ProjectableFlattenMaybe (Maybe b) c) => Record cont (Maybe a) -> Pi a b -> Record cont c

relational-query Database.Relational.Arrow Database.Relational.Projectable

Get narrower record with flatten leaf phantom Maybe types along with projection path.

flattenMaybe :: Record c (Maybe (Maybe a)) -> Record c (Maybe a)

relational-query Database.Relational.Record

Composite nested Maybe on record phantom type.

class ProjectableFlattenMaybe a b

relational-query Database.Relational.Arrow Database.Relational.Projectable

Interface to compose phantom Maybe nested type.