Data.HTree.Families

generic types and type families used in some of the modules

Documentation

type family All c xs where ...

for all elements of a list, a contraint holds

Equations

All c '[] = ()

All c (x : xs) = (c x, All c xs)

class All c xs => AllC c xs

like All but can be partially applied

Instances

All c xs => AllC (c :: k -> Constraint) (xs :: [k])

Defined in Data.HTree.Families

class AllInv l k

All but inversed: holds if all constraints in the list hold

Instances

AllInv ('[] :: [k1 -> Constraint]) (k2 :: k1)

Defined in Data.HTree.Families

(c k2, AllInv cs k2) => AllInv (c ': cs :: [k1 -> Constraint]) (k2 :: k1)

Defined in Data.HTree.Families

class (c1 a, c2 a) => Both c1 c2 a

product of two classes

Instances

(c1 a, c2 a) => Both (c1 :: k -> Constraint) (c2 :: k -> Constraint) (a :: k)

Defined in Data.HTree.Families

(forall x. Eq x => Eq (f x), Typeable f) => Eq (EList (Has (Both (Typeable :: Type -> Constraint) Eq) f))

Defined in Data.HTree.Existential

Methods

(==) :: EList (Has (Both Typeable Eq) f) -> EList (Has (Both Typeable Eq) f) -> Bool

(/=) :: EList (Has (Both Typeable Eq) f) -> EList (Has (Both Typeable Eq) f) -> Bool

(forall x. Eq x => Eq (f x), Typeable f) => Eq (ETree (Has (Both (Typeable :: Type -> Constraint) Eq) f))

Defined in Data.HTree.Existential

Methods

(==) :: ETree (Has (Both Typeable Eq) f) -> ETree (Has (Both Typeable Eq) f) -> Bool

(/=) :: ETree (Has (Both Typeable Eq) f) -> ETree (Has (Both Typeable Eq) f) -> Bool

type family Not a where ...

like not but on the type level

Equations

Not 'True = 'False

Not 'False = 'True

class Top k

the class that every type has an instance for

Instances

Top (k2 :: k1)

Defined in Data.HTree.Families

type family xs ++ ys where ... infixr 5

like 'Prelude.(++)' on the value level but on the type level

Equations

'[] ++ ys = ys

(x : xs) ++ ys = x : (xs ++ ys)

type family a || b where ...

typelevel Or

Equations

'True || b = 'True

'False || b = b