Safe Haskell | None |
---|---|
Language | Haskell98 |
Data.Random.Source
Contents
- class Monad m => MonadRandom m where
- class Monad m => RandomSource m s where
- monadRandom :: Q [Dec] -> Q [Dec]
- randomSource :: Q [Dec] -> Q [Dec]
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
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 # | |
Monad m => RandomSource m (GetPrim m) # | |
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... -} |])
Orphan instances
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) # | |