ForSyDe.Deep.AbsentExt

The AbstExt is used to extend existing data types with the value 'absent', which models the absence of a value.

Documentation

data AbstExt a

The data type AbstExt has two constructors. The constructor Abst is used to model the absence of a value, while the constructor Prst is used to model present values.

Constructors

Abst

Prst a

Instances

Eq a => Eq (AbstExt a)

Methods

(==) :: AbstExt a -> AbstExt a -> Bool

(/=) :: AbstExt a -> AbstExt a -> Bool

Data a => Data (AbstExt a)

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> AbstExt a -> c (AbstExt a)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (AbstExt a)

toConstr :: AbstExt a -> Constr

dataTypeOf :: AbstExt a -> DataType

dataCast1 :: Typeable (* -> *) t => (forall d. Data d => c (t d)) -> Maybe (c (AbstExt a))

dataCast2 :: Typeable (* -> * -> *) t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (AbstExt a))

gmapT :: (forall b. Data b => b -> b) -> AbstExt a -> AbstExt a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> AbstExt a -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> AbstExt a -> r

gmapQ :: (forall d. Data d => d -> u) -> AbstExt a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> AbstExt a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> AbstExt a -> m (AbstExt a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> AbstExt a -> m (AbstExt a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> AbstExt a -> m (AbstExt a)

Read a => Read (AbstExt a)

Methods

readsPrec :: Int -> ReadS (AbstExt a)

readList :: ReadS [AbstExt a]

readPrec :: ReadPrec (AbstExt a)

readListPrec :: ReadPrec [AbstExt a]

Show a => Show (AbstExt a)

The data type AbstExt is defined as an instance of Show and Read. '_' represents the value Abst while a present value is represented with its value, e.g. Prst 1 is represented as '1'.

Methods

showsPrec :: Int -> AbstExt a -> ShowS

show :: AbstExt a -> String

showList :: [AbstExt a] -> ShowS

Lift a0 => Lift (AbstExt a0)

Methods

lift :: AbstExt a0 -> Q Exp

fromAbstExt

Arguments

:: a

Default value returned if the input is Abst

-> AbstExt a

-> a

The function fromAbstExt extracts the inner value contained in AbstExt

unsafeFromAbstExt :: AbstExt a -> a

Similar to fromAbstExt, but without default value

abstExt :: a -> AbstExt a

The function abstExt converts a usual value to a present value.

psi :: (a -> b) -> AbstExt a -> AbstExt b

The function psi is identical to abstExtFunc and should be used in future.

isAbsent :: AbstExt a -> Bool

The functions isAbsent checks for the absence of a value.

isPresent :: AbstExt a -> Bool

The functions isPresent checks for the presence of a value.

abstExtFunc :: (a -> b) -> AbstExt a -> AbstExt b

The function abstExtFunc extends a function in order to process absent extended values. If the input is ("bottom"), the output will also be ("bottom").