Safe Haskell	None
Language	Haskell2010

Random

Description

Library functions about randomness

Synopsis

pick :: RandomGen r => r -> [a] -> (Maybe a, r)
pickM :: RandomGen r => MonadState r m => [a] -> m (Maybe a)
shuffle :: RandomGen r => r -> [a] -> ([a], r)
shuffleM :: RandomGen r => MonadState r m => [a] -> m [a]
oneof :: RandomGen r => MonadState r m => NonEmpty a -> m a
roll :: RandomGen r => MonadState r m => Random p => Ord p => p -> p -> m p

Documentation

pick :: RandomGen r => r -> [a] -> (Maybe a, r) #

Pick one element at random from the second argument, using the given random generator. Returns the updated generator and the picked element (being Just if the list non-empty). See oneof for a variant of this function.

pickM #

Arguments

:: RandomGen r
=> MonadState r m
=> [a]	The elements from which something must be picked
-> m (Maybe a)

Returns a random element from the list, if it is non empty. If you a non-empty list at hand, call oneof instead.

shuffle :: RandomGen r => r -> [a] -> ([a], r) #

Shuffles the second argument with the random generator. Returns the shuffle and the updated generator.

shuffleM :: RandomGen r => MonadState r m => [a] -> m [a] #

Shuffles the given list with a random generator

oneof #

Arguments

:: RandomGen r
=> MonadState r m
=> NonEmpty a	The elements from which something must be picked
-> m a

Returns a random element from the list. If you have a possibly empty list at hand, call pickM instead.

roll #

Arguments

:: RandomGen r
=> MonadState r m
=> Random p
=> Ord p
=> p	The minimum element
-> p	The maximum element
-> m p

'roll min max' returns a value between min (included) and max (included). 'min <= max' should hold.