base-4.20.0.1: Core data structures and operations
LicenseBSD-style (see the LICENSE file in the distribution)
Maintainerlibraries@haskell.org
Stabilitystable
Portabilitynot portable
Safe HaskellSafe
LanguageHaskell2010

Data.Type.Bool

Description

Basic operations on type-level Booleans.

Since: base-4.7.0.0

Synopsis
  • type family If (cond :: Bool) (tru :: k) (fls :: k) :: k where ...
  • type family (a :: Bool) && (b :: Bool) :: Bool where ...
  • type family (a :: Bool) || (b :: Bool) :: Bool where ...
  • type family Not (a :: Bool) = (res :: Bool) | res -> a where ...

Documentation

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

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 Source #

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 Source #

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 ... Source #

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