Control.Monad.LazyRandom

License : BSD3

A lazy monad for random-number generation. This monad allows, for example, computation of infinite random lists.

This monad respects the interface defined by MonadRandom.

A monadic computation is one that consumes random values. The bind operation works like the Gen monad in QuickCheck: it does not thread the random seed; instead it *splits* the random seed.

Documentation

module System.Random

module Control.Monad.Random.Class

evalRand :: RandomGen g => Rand g a -> g -> a

Evaluate a random computation using the generator g. The new g is discarded.

runRand :: RandomGen g => Rand g a -> g -> (a, g)

Run a random computation using the generator g, returning the result and a new generator.

evalRandIO :: Rand StdGen a -> IO a

Evaluate a random computation in the IO monad, using the random number generator supplied by getStdRandom.

data Rand g a

Instances

RandomGen g => MonadSplit g (Rand g)

Methods

getSplit :: Rand g g

RandomGen g => Monad (Rand g)

Methods

(>>=) :: Rand g a -> (a -> Rand g b) -> Rand g b

(>>) :: Rand g a -> Rand g b -> Rand g b

return :: a -> Rand g a

fail :: String -> Rand g a

Functor (Rand g)

A value of type 'Rand g a' is a monadic computation which, when run, consumes random values from an applicative random-number generator of type g and produces a result of type a.

Methods

fmap :: (a -> b) -> Rand g a -> Rand g b

(<$) :: a -> Rand g b -> Rand g a

RandomGen g => Applicative (Rand g)

Methods

pure :: a -> Rand g a

(<*>) :: Rand g (a -> b) -> Rand g a -> Rand g b

(*>) :: Rand g a -> Rand g b -> Rand g b

(<*) :: Rand g a -> Rand g b -> Rand g a

RandomGen g => MonadRandom (Rand g)

Methods

getRandom :: Random a => Rand g a

getRandoms :: Random a => Rand g [a]

getRandomR :: Random a => (a, a) -> Rand g a

getRandomRs :: Random a => (a, a) -> Rand g [a]