-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/

-- | Fast Splittable PRNG
--   
--   Pure Haskell implementation of SplitMix described in
--   
--   Guy L. Steele, Jr., Doug Lea, and Christine H. Flood. 2014. Fast
--   splittable pseudorandom number generators. In Proceedings of the 2014
--   ACM International Conference on Object Oriented Programming Systems
--   Languages & Applications (OOPSLA '14). ACM, New York, NY, USA,
--   453-472. DOI: https://doi.org/10.1145/2660193.2660195
--   
--   The paper describes a new algorithm SplitMix for
--   splittable pseudorandom number generator that is quite fast: 9
--   64 bit arithmetic/logical operations per 64 bits generated.
--   
--   SplitMix is tested with two standard statistical test suites
--   (DieHarder and TestU01, this implementation only using the former) and
--   it appears to be adequate for "everyday" use, such as Monte Carlo
--   algorithms and randomized data structures where speed is important.
--   
--   In particular, it should not be used for cryptographic or security
--   applications, because generated sequences of pseudorandom values
--   are too predictable (the mixing functions are easily inverted, and two
--   successive outputs suffice to reconstruct the internal state).
@package splitmix
@version 0.0.2

-- | SplitMix is a splittable pseudorandom number generator (PRNG)
--   that is quite fast.
--   
--   Guy L. Steele, Jr., Doug Lea, and Christine H. Flood. 2014. Fast
--   splittable pseudorandom number generators. In Proceedings of the
--   2014 ACM International Conference on Object Oriented Programming
--   Systems Languages & Applications (OOPSLA '13). ACM, New York,
--   NY, USA, 453-472. DOI: https://doi.org/10.1145/2660193.2660195
--   
--   Guy L. Steele, Jr., Doug Lea, and Christine H. Flood. 2014. Fast
--   splittable pseudorandom number generators. In Proceedings of the 2014
--   ACM International Conference on Object Oriented Programming Systems
--   Languages & Applications (OOPSLA '14). ACM, New York, NY, USA,
--   453-472. DOI: https://doi.org/10.1145/2660193.2660195
--   
--   The paper describes a new algorithm SplitMix for
--   splittable pseudorandom number generator that is quite fast: 9
--   64 bit arithmetic/logical operations per 64 bits generated.
--   
--   SplitMix is tested with two standard statistical test suites
--   (DieHarder and TestU01, this implementation only using the former) and
--   it appears to be adequate for "everyday" use, such as Monte Carlo
--   algorithms and randomized data structures where speed is important.
--   
--   In particular, it should not be used for cryptographic or security
--   applications, because generated sequences of pseudorandom values
--   are too predictable (the mixing functions are easily inverted, and two
--   successive outputs suffice to reconstruct the internal state).
--   
--   Note: This module supports all GHCs since GHC-7.0.4, but GHC-7.0 and
--   GHC-7.2 have slow implementation, as there are no native
--   popCount.
module System.Random.SplitMix

-- | SplitMix generator state.
data SMGen

-- | Generate a Word64.
--   
--   
--   >>> take 3 $ map (printf "%x") $ unfoldr (Just . nextWord64) (mkSMGen 1337) :: [String]
--   ["b5c19e300e8b07b3","d600e0e216c0ac76","c54efc3b3cc5af29"]
--   
nextWord64 :: SMGen -> (Word64, SMGen)

-- | Generate an Int.
nextInt :: SMGen -> (Int, SMGen)

-- | Generate a Double in [0, 1) range.
--   
--   
--   >>> take 8 $ map (printf "%0.3f") $ unfoldr (Just . nextDouble) (mkSMGen 1337) :: [String]
--   ["0.710","0.836","0.771","0.409","0.297","0.527","0.589","0.067"]
--   
nextDouble :: SMGen -> (Double, SMGen)

-- | Split a generator into a two uncorrelated generators.
splitSMGen :: SMGen -> (SMGen, SMGen)

-- | Preferred way to deterministically construct SMGen.
--   
--   
--   >>> mkSMGen 42
--   SMGen 9297814886316923340 13679457532755275413
--   
mkSMGen :: Word64 -> SMGen

-- | Initialize SMGen using system time.
initSMGen :: IO SMGen

-- | Derive a new generator instance from the global SMGen using
--   splitSMGen.
newSMGen :: IO SMGen

-- | Create SMGen using seed and gamma.
--   
--   
--   >>> seedSMGen 2 2
--   SMGen 2 3
--   
seedSMGen :: Word64 -> Word64 -> SMGen

-- | Like seedSMGen but takes a pair.
seedSMGen' :: (Word64, Word64) -> SMGen

-- | Extract current state of SMGen.
unseedSMGen :: SMGen -> (Word64, Word64)
instance GHC.Show.Show System.Random.SplitMix.SMGen
instance Control.DeepSeq.NFData System.Random.SplitMix.SMGen
instance GHC.Read.Read System.Random.SplitMix.SMGen
instance System.Random.RandomGen System.Random.SplitMix.SMGen
