Data.Type.Bool

Basic operations on type-level Booleans.

Since: base-4.7.0.0

Documentation

type family If (cond :: Bool) (tru :: k) (fls :: k) :: k where ...

Type-level If. If True a b ==> a; If False a b ==> b

Equations

If 'True (tru :: k) (fls :: k) = tru

If 'False (tru :: k) (fls :: k) = fls

type family (a :: Bool) && (b :: Bool) :: Bool where ... infixr 3

Type-level "and"

Equations

'False && a = 'False

'True && a = a

a && 'False = 'False

a && 'True = a

a && a = a

type family (a :: Bool) || (b :: Bool) :: Bool where ... infixr 2

Type-level "or"

Equations

'False || a = a

'True || a = 'True

a || 'False = a

a || 'True = 'True

a || a = a

type family Not (a :: Bool) = (res :: Bool) | res -> a where ...

Type-level "not". An injective type family since 4.10.0.0.

Since: base-4.7.0.0

Equations

Not 'False = 'True

Not 'True = 'False