Feldspar.Data.Validated

Validated values

Validated is similar to Option, with the difference that Validated does not guarantee that invalid values are not evaluated. Therefore, Validated should not be used to guard operations from illegal use (e.g. array bounds checking).

Still, the operations try to defer evaluation of invalid values as much as possible.

Documentation

data Validated a

A value that can be valid or invalid

Constructors

Validated (Data Bool) a

Instances

Monad Validated

Methods

(>>=) :: Validated a -> (a -> Validated b) -> Validated b

(>>) :: Validated a -> Validated b -> Validated b

return :: a -> Validated a

fail :: String -> Validated a

Functor Validated

Methods

fmap :: (a -> b) -> Validated a -> Validated b

(<$) :: a -> Validated b -> Validated a

Applicative Validated

Methods

pure :: a -> Validated a

(<*>) :: Validated (a -> b) -> Validated a -> Validated b

(*>) :: Validated a -> Validated b -> Validated b

(<*) :: Validated a -> Validated b -> Validated a

Syntax a => Syntactic (Validated a)

Associated Types

type Domain (Validated a) :: * -> *

type Internal (Validated a) :: *

Methods

desugar :: Validated a -> ASTF (Domain (Validated a)) (Internal (Validated a))

sugar :: ASTF (Domain (Validated a)) (Internal (Validated a)) -> Validated a

Forcible a => Forcible (Validated a)

toValue will force the value even if it's invalid

Associated Types

type ValueRep (Validated a) :: *

Methods

toValue :: MonadComp m => Validated a -> m (ValueRep (Validated a))

fromValue :: ValueRep (Validated a) -> Validated a

type Internal (Validated a)

type Internal (Validated a) = (Bool, Internal a)

type Domain (Validated a)

type Domain (Validated a) = FeldDomain

type ValueRep (Validated a)

type ValueRep (Validated a) = (Data Bool, ValueRep a)

validWhen :: Data Bool -> a -> Validated a

Create a validated value. Note that the value may get evaluated even if the condition is false.

invalid :: Syntax a => Validated a

Invalid value

validated

Arguments

:: Syntax b

=> b

Invalid case

-> (a -> b)

Valid case

-> Validated a

-> b

Deconstruct an Validated value

caseValidated

Arguments

:: Syntax b

=> Validated a

-> b

Invalid case

-> (a -> b)

Valid case

-> b

Deconstruct an Validated value

fromValidated

Arguments

:: Syntax a

=> Validated a

-> a

Value to return in case the first arg. is invalid

-> a

validatedM

Arguments

:: MonadComp m

=> m ()

Invalid case

-> (a -> m ())

Valid case

-> Validated a

-> m ()

Deconstruct an Validated value

caseValidatedM

Arguments

:: MonadComp m

=> Validated a

-> m ()

Invalid case

-> (a -> m ())

Valid case

-> m ()

Deconstruct an Validated value