Data.Monoid.MList

Operator alias for Data.Monoid.MList.Perhaps (non-associative / precedence 5)

Operator alias for Data.Monoid.MList.perhaps (non-associative / precedence 5)

class MList l  where

Type class for heterogeneous monoidal lists, with a single method

Members

• empty :: l

  The /empty/ heterogeneous list of type @l@. Of course, @empty

Instances

• MList Unit
• (MList l) => MList (Perhaps a l)

class Includes l a  where

The relation @l Includes a@ holds when @a@ is the type of an element

Members

• inj :: a -> l

  Inject a value into an otherwise empty heterogeneous list.

• get :: l -> Maybe a

  Get the value of type @a@ from a heterogeneous list, if there

• alt :: (Maybe a -> Maybe a) -> l -> l

  Alter the value of type @a@ by applying the given function to it.

Instances

• (MList t) => Includes (Perhaps a t) a
• (Includes t a) => Includes (Perhaps b t) a

type Perhaps a l = (Maybe a) /\ l

Instances

• (MList l) => MList (Perhaps a l)
• (MList t) => Includes (Perhaps a t) a
• (Includes t a) => Includes (Perhaps b t) a

perhaps :: forall a l. a -> l -> a ::: l

newtype SM m

@SM@, an abbreviation for "single monoid" (as opposed to a

Constructors

• SM m

Instances

• Generic (SM m) _
• (Show m) => Show (SM m)
• (Monoid (SM a)) => Action (SM a) Unit
• (Action a a', Action (SM a) l) => Action (SM a) (Tuple (Maybe a') l)