Safe Haskell	None
Language	Haskell2010

Data.Singletons.Bool

Contents

Data.Type.Dec
Data.Type.Bool and .Equality

Description

Additions to Data.Type.Bool.

Synopsis

data SBool (b :: Bool) where
- STrue :: SBool 'True
- SFalse :: SBool 'False
class SBoolI (b :: Bool) where
- sbool :: SBool b
fromSBool :: SBool b -> Bool
withSomeSBool :: Bool -> (forall b. SBool b -> r) -> r
reflectBool :: forall b proxy. SBoolI b => proxy b -> Bool
reifyBool :: forall r. Bool -> (forall b. SBoolI b => Proxy b -> r) -> r
discreteBool :: forall a b. (SBoolI a, SBoolI b) => Dec (a :~: b)
sboolAnd :: SBool a -> SBool b -> SBool (a && b)
sboolOr :: SBool a -> SBool b -> SBool (a || b)
sboolNot :: SBool a -> SBool (Not a)
eqToRefl :: (a == b) ~ 'True => a :~: b
eqCast :: (a == b) ~ 'True => a -> b
sboolEqRefl :: forall k (a :: k) (b :: k). SBoolI (a == b) => Maybe (a :~: b)
trivialRefl :: () :~: ()

Documentation

data SBool (b :: Bool) where Source #

Constructors

STrue :: SBool 'True
SFalse :: SBool 'False

Instances

Instances details

GShow SBool Source #	`>>>` `showsPrec 0 STrue ""`"STrue" Since: 0.1.6
Instance details Defined in Data.Singletons.Bool Methods gshowsPrec :: forall (a :: k). Int -> SBool a -> ShowS #
GRead SBool Source #	`>>>` `readsPrec 0 "Some STrue" :: [(Some SBool, String)]`[(Some STrue,"")] `>>>` `readsPrec 0 "Some SFalse" :: [(Some SBool, String)]`[(Some SFalse,"")] `>>>` `readsPrec 0 "Some Else" :: [(Some SBool, String)]`[] Since: 0.1.6
Instance details Defined in Data.Singletons.Bool Methods greadsPrec :: Int -> GReadS SBool #
GEq SBool Source #	`>>>` `geq STrue STrue`Just Refl `>>>` `geq STrue SFalse`Nothing Since: 0.1.6
Instance details Defined in Data.Singletons.Bool Methods geq :: forall (a :: k) (b :: k). SBool a -> SBool b -> Maybe (a :~: b) #
GCompare SBool Source #	Since: 0.1.6
Instance details Defined in Data.Singletons.Bool Methods gcompare :: forall (a :: k) (b :: k). SBool a -> SBool b -> GOrdering a b #
GNFData SBool Source #	Since: 0.1.6
Instance details Defined in Data.Singletons.Bool Methods grnf :: forall (a :: k). SBool a -> () #
Eq (SBool b) Source #	Since: 0.1.5
Instance details Defined in Data.Singletons.Bool Methods (==) :: SBool b -> SBool b -> Bool # (/=) :: SBool b -> SBool b -> Bool #
Ord (SBool b) Source #	Since: 0.1.5
Instance details Defined in Data.Singletons.Bool Methods compare :: SBool b -> SBool b -> Ordering # (<) :: SBool b -> SBool b -> Bool # (<=) :: SBool b -> SBool b -> Bool # (>) :: SBool b -> SBool b -> Bool # (>=) :: SBool b -> SBool b -> Bool # max :: SBool b -> SBool b -> SBool b # min :: SBool b -> SBool b -> SBool b #
Show (SBool b) Source #	Since: 0.1.5
Instance details Defined in Data.Singletons.Bool Methods showsPrec :: Int -> SBool b -> ShowS # show :: SBool b -> String # showList :: [SBool b] -> ShowS #
SBoolI b => Boring (SBool b) Source #	Since: 0.1.6
Instance details Defined in Data.Singletons.Bool Methods boring :: SBool b #
NFData (SBool b) Source #	Since: 0.1.6
Instance details Defined in Data.Singletons.Bool Methods rnf :: SBool b -> () #

class SBoolI (b :: Bool) where Source #

Methods

sbool :: SBool b Source #

Instances

Instances details

SBoolI 'False Source #
Instance details Defined in Data.Singletons.Bool Methods sbool :: SBool 'False Source #
SBoolI 'True Source #
Instance details Defined in Data.Singletons.Bool Methods sbool :: SBool 'True Source #

fromSBool :: SBool b -> Bool Source #

Convert an SBool to the corresponding Bool.

Since: 0.1.4

withSomeSBool :: Bool -> (forall b. SBool b -> r) -> r Source #

Convert a normal Bool to an SBool, passing it into a continuation.

>>> withSomeSBool True fromSBool
True

Since: 0.1.4

reflectBool :: forall b proxy. SBoolI b => proxy b -> Bool Source #

Reflect to term-level.

>>> reflectBool (Proxy :: Proxy 'True)
True

reifyBool :: forall r. Bool -> (forall b. SBoolI b => Proxy b -> r) -> r Source #

Reify Bool to type-level.

>>> reifyBool True reflectBool
True

Data.Type.Dec

discreteBool is available with base >= 4.7 (GHC-7.8)

discreteBool :: forall a b. (SBoolI a, SBoolI b) => Dec (a :~: b) Source #

Decidable equality.

>>> decShow (discreteBool :: Dec ('True :~: 'True))
"Yes Refl"

Since: 0.1.5

Data.Type.Bool and .Equality

These are only defined with base >= 4.7

sboolAnd :: SBool a -> SBool b -> SBool (a && b) Source #

>>> sboolAnd STrue SFalse
SFalse

sboolOr :: SBool a -> SBool b -> SBool (a || b) Source #

sboolNot :: SBool a -> SBool (Not a) Source #

eqToRefl :: (a == b) ~ 'True => a :~: b Source #

Since: 0.1.1.0

eqCast :: (a == b) ~ 'True => a -> b Source #

Since: 0.1.1.0

sboolEqRefl :: forall k (a :: k) (b :: k). SBoolI (a == b) => Maybe (a :~: b) Source #

Useful combination of sbool and eqToRefl

Since: 0.1.2.0

trivialRefl :: () :~: () Source #

Since: 0.1.1.0