Data.Random.Source

Documentation

class Monad m => MonadRandom m where

A typeclass for monads with a chosen source of entropy. For example, RVar is such a monad - the source from which it is (eventually) sampled is the only source from which a random variable is permitted to draw, so when directly requesting entropy for a random variable these functions are used.

Minimum implementation is either the internal getRandomPrim or all other functions. Additionally, this class's interface is subject to extension at any time, so it is very, very strongly recommended that the monadRandom Template Haskell function be used to implement this function rather than directly implementing it. That function takes care of choosing default implementations for any missing functions; as long as at least one function is implemented, it will derive sensible implementations of all others.

To use monadRandom, just wrap your instance declaration as follows (and enable the TemplateHaskell and GADTs language extensions):

 $(monadRandom [d|
         instance MonadRandom FooM where
             getRandomDouble = return pi
             getRandomWord16 = return 4
             {- etc... -}
     |])

Methods

getRandomWord8 :: m Word8

Generate a uniformly distributed random Word8

getRandomWord16 :: m Word16

Generate a uniformly distributed random Word16

getRandomWord32 :: m Word32

Generate a uniformly distributed random Word32

getRandomWord64 :: m Word64

Generate a uniformly distributed random Word64

getRandomDouble :: m Double

Generate a uniformly distributed random Double in the range 0 <= U < 1

getRandomNByteInteger :: MonadRandom m => Int -> m Integer

Generate a uniformly distributed random Integer in the range 0 <= U < 256^n

Instances

MonadRandom IO

Monad m0 => MonadRandom (StateT PureMT m0)

Monad m => MonadRandom (StateT StdGen m)

Monad m0 => MonadRandom (StateT PureMT m0)

Monad m => MonadRandom (StateT StdGen m)

class Monad m => RandomSource m s where

A source of entropy which can be used in the given monad.

See also MonadRandom.

Minimum implementation is either the internal getRandomPrimFrom or all other functions. Additionally, this class's interface is subject to extension at any time, so it is very, very strongly recommended that the randomSource Template Haskell function be used to implement this function rather than directly implementing it. That function takes care of choosing default implementations for any missing functions; as long as at least one function is implemented, it will derive sensible implementations of all others.

To use randomSource, just wrap your instance declaration as follows (and enable the TemplateHaskell, MultiParamTypeClasses and GADTs language extensions, as well as any others required by your instances, such as FlexibleInstances):

 $(randomSource [d|
         instance RandomSource FooM Bar where
             {- at least one RandomSource function... -}
     |])

Methods

getRandomWord8From :: s -> m Word8

Generate a uniformly distributed random Word8

getRandomWord16From :: s -> m Word16

Generate a uniformly distributed random Word16

getRandomWord32From :: s -> m Word32

Generate a uniformly distributed random Word32

getRandomWord64From :: s -> m Word64

Generate a uniformly distributed random Word64

getRandomDoubleFrom :: s -> m Double

Generate a uniformly distributed random Double in the range 0 <= U < 1

getRandomNByteIntegerFrom :: s -> Int -> m Integer

Generate a uniformly distributed random Integer in the range 0 <= U < 256^n

Instances

RandomSource IO DevRandom

MonadRandom m => RandomSource m StdRandom

RandomSource IO (Gen RealWorld)

Monad m => RandomSource m (GetPrim m)

(Monad m, ModifyRef (IORef StdGen) m StdGen) => RandomSource m (IORef StdGen)

MonadIO m0 => RandomSource m0 (IORef PureMT)

Monad m0 => RandomSource m0 (m0 Word8)

Monad m0 => RandomSource m0 (m0 Word16)

Monad m0 => RandomSource m0 (m0 Word32)

Monad m0 => RandomSource m0 (m0 Word64)

Monad m0 => RandomSource m0 (m0 Double)

(Monad m, ModifyRef (STRef s StdGen) m StdGen) => RandomSource m (STRef s StdGen)

(Monad m1, ModifyRef (Ref m2 StdGen) m1 StdGen) => RandomSource m1 (Ref m2 StdGen)

(Monad m10, ModifyRef (Ref m20 PureMT) m10 PureMT) => RandomSource m10 (Ref m20 PureMT)

(Monad m0, ModifyRef (STRef s0 PureMT) m0 PureMT) => RandomSource m0 (STRef s0 PureMT)

RandomSource (ST s0) (Gen s0)

monadRandom :: Q [Dec] -> Q [Dec]

Complete a possibly-incomplete MonadRandom implementation. It is recommended that this macro be used even if the implementation is currently complete, as the MonadRandom class may be extended at any time.

To use monadRandom, just wrap your instance declaration as follows (and enable the TemplateHaskell and GADTs language extensions):

 $(monadRandom [d|
         instance MonadRandom FooM where
             getRandomDouble = return pi
             getRandomWord16 = return 4
             {- etc... -}
     |])

randomSource :: Q [Dec] -> Q [Dec]

Complete a possibly-incomplete RandomSource implementation. It is recommended that this macro be used even if the implementation is currently complete, as the RandomSource class may be extended at any time.

To use randomSource, just wrap your instance declaration as follows (and enable the TemplateHaskell, MultiParamTypeClasses and GADTs language extensions, as well as any others required by your instances, such as FlexibleInstances):

 $(randomSource [d|
         instance RandomSource FooM Bar where
             {- at least one RandomSource function... -}
     |])