Safe Haskell	None
Language	Haskell2010

Data.OpenWitness

Synopsis

data OpenWitness :: * -> forall (k :: *). k -> *
data RealWorld
type IOWitness = OpenWitness RealWorld
newIOWitness :: forall a. IO (IOWitness a)
data OW s a
newOpenWitnessOW :: forall s a. OW s (OpenWitness s a)
runOW :: forall a. (forall s. OW s a) -> a
owToIO :: OW RealWorld a -> IO a
iowitness :: TypeQ -> Q Exp

Documentation

data OpenWitness :: * -> forall (k :: *). k -> * #

A witness type that can witness to any type. But values cannot be constructed; they can only be generated in IO and certain other monads.

Instances

TestEquality (OpenWitness s k :: k -> *) #
Instance details Defined in Data.OpenWitness Methods testEquality :: OpenWitness s k a -> OpenWitness s k b -> Maybe (a :~: b) #
TestHetEquality (OpenWitness s) #
Instance details Defined in Data.OpenWitness Methods testHetEquality :: OpenWitness s ka a -> OpenWitness s kb b -> Maybe (HetEq a b) #
Eq (OpenWitness s k a) #
Instance details Defined in Data.OpenWitness Methods (==) :: OpenWitness s k a -> OpenWitness s k a -> Bool # (/=) :: OpenWitness s k a -> OpenWitness s k a -> Bool #

data RealWorld #

The s type for running OW in IO.

type IOWitness = OpenWitness RealWorld #

An OpenWitness for IO.

newIOWitness :: forall a. IO (IOWitness a) #

Generate a new IOWitness in IO.

data OW s a #

A runnable monad in which OpenWitness values can be generated. The s parameter plays the same role as it does in ST, preventing OpenWitness values from one run being used in another.

Instances

Monad (OW s) #
Instance details Defined in Data.OpenWitness Methods (>>=) :: OW s a -> (a -> OW s b) -> OW s b # (>>) :: OW s a -> OW s b -> OW s b # return :: a -> OW s a # fail :: String -> OW s a #
Functor (OW s) #
Instance details Defined in Data.OpenWitness Methods fmap :: (a -> b) -> OW s a -> OW s b # (<$) :: a -> OW s b -> OW s a #
MonadFix (OW s) #
Instance details Defined in Data.OpenWitness Methods mfix :: (a -> OW s a) -> OW s a #
Applicative (OW s) #
Instance details Defined in Data.OpenWitness Methods pure :: a -> OW s a # (<>) :: OW s (a -> b) -> OW s a -> OW s b # liftA2 :: (a -> b -> c) -> OW s a -> OW s b -> OW s c # (>) :: OW s a -> OW s b -> OW s b # (<*) :: OW s a -> OW s b -> OW s a #

newOpenWitnessOW :: forall s a. OW s (OpenWitness s a) #

Generate a new OpenWitness in OW.

runOW :: forall a. (forall s. OW s a) -> a #

Run an OW computation.

owToIO :: OW RealWorld a -> IO a #

Run an OW computation in IO.

iowitness :: TypeQ -> Q Exp #

Template Haskell function to declare IOWitness values.