mersenne-random 0.1.3 → 1.0

raw patch · 2 files changed

+76/−1 lines, 2 files

Files

• System/Random/Mersenne.hs +71/−0
• mersenne-random.cabal +5/−1

@@ -35,6 +35,11 @@     -- $notes     , MTRandom(..) +    -- $globalrng+    , getStdRandom+    , getStdGen+    , setStdGen+     -- * Miscellaneous     , version @@ -58,6 +63,7 @@ import Data.Int import Data.Bits import Data.Char+import Data.IORef  ------------------------------------------------------------------------ -- $example@@ -187,65 +193,90 @@                 return (x : xs) -} +  -- | A variant of 'random' that uses the global random number generator+  -- (see "System.Random#globalrng").+  -- Essentially a convenience function if you're already in IO.+  --+  -- Note that there are performance penalties calling randomIO in an+  -- inner loop, rather than 'random' applied to a global generator. The+  -- cost comes in retrieving the random gen from an IORef, which is+  -- non-trivial. Expect a 3x slow down in speed of random generation.+  randomIO :: IO a+  randomIO = getStdRandom random+  {-# INLINE randomIO #-}+ ------------------------------------------------------------------------ -- Efficient basic instances  instance MTRandom Word    where     random !_          = randomWord+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalWord g (fromIntegral lo) (fromIntegral hi)  instance MTRandom Word64  where     random !_ = fmap fromIntegral randomWord64+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalWord g (fromIntegral lo) (fromIntegral hi)  instance MTRandom Word32  where     random !_ = fmap fromIntegral randomWord+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalWord g (fromIntegral lo) (fromIntegral hi)  instance MTRandom Word16  where     random !_ = fmap fromIntegral randomWord+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalWord g (fromIntegral lo) (fromIntegral hi)  instance MTRandom Word8   where     random !_          = fmap fromIntegral randomWord+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalWord g (fromIntegral lo) (fromIntegral hi)  ------------------------------------------------------------------------  instance MTRandom Double where     random !_ = randomDouble+    {-# INLINE random #-} --    randomR (lo,hi) g = randomIvalDouble g lo hi id  ------------------------------------------------------------------------  instance MTRandom Int     where     random !_          = randomInt+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalInt g lo hi  instance MTRandom Int64   where     random !_ = fmap fromIntegral randomInt64+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalInt g (fromIntegral lo) (fromIntegral hi)  instance MTRandom Int32   where     random !_ = fmap fromIntegral randomInt+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalInt g (fromIntegral lo) (fromIntegral hi)  instance MTRandom Int16   where     random !_ = fmap fromIntegral randomInt+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalInt g (fromIntegral lo) (fromIntegral hi)  instance MTRandom Int8    where     random !_ = fmap fromIntegral randomInt+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalInt g (fromIntegral lo) (fromIntegral hi)  instance MTRandom Integer where     random !_ = fmap fromIntegral randomInt+    {-# INLINE random #-} --    randomR (lo,hi) !g = randomIvalInt g (fromIntegral lo) (fromIntegral hi)  ------------------------------------------------------------------------  instance MTRandom Bool    where     random !_ = do x <- randomWord; return $! x .&. 1 /= 0+    {-# INLINE random #-}  {-     randomR (a,b) !g = int2Bool `fmap` randomIvalInt g (bool2Int a) (bool2Int b)@@ -327,6 +358,46 @@ intRange :: Integer intRange = toInteger (maxBound::Int) - toInteger (minBound::Int) -}+------------------------------------------------------------------------+--+-- Using a single global random number generator+--++{- $globalrng #globalrng#++There is a single, implicit, global random number generator of type+'StdGen', held in some global variable maintained by the 'IO' monad. It is+initialised automatically in some system-dependent fashion. To get+deterministic behaviour, use 'setStdGen'.+-}++theStdGen :: IORef MTGen+theStdGen  = unsafePerformIO $ do+   rng <- newMTGen Nothing+   newIORef rng+{-# NOINLINE theStdGen #-}++-- |Sets the global random number generator.+setStdGen :: MTGen -> IO ()+setStdGen = writeIORef theStdGen++-- |Gets the global random number generator.+getStdGen :: IO MTGen+getStdGen  = readIORef theStdGen++-- | Uses the supplied function to get a value from the current global+-- random generator, and updates the global generator with the new+-- generator returned by the function. For example, @rollDice@ gets a+-- random integer between 1 and 6:+--+-- >  rollDice :: IO Int+-- >  rollDice = getMTRandom (randomR (1,6))+--+getStdRandom :: (MTGen -> IO a) -> IO a+getStdRandom f = do+    st <- readIORef theStdGen+    f st+{-# INLINE getStdRandom #-}  ------------------------------------------------------------------------ 

@@ -1,5 +1,5 @@ name:            mersenne-random-version:         0.1.3+version:         1.0 homepage:        http://code.haskell.org/~dons/code/mersenne-random synopsis:        Generate high quality pseudorandom numbers using a SIMD Fast Mersenne Twister description:@@ -13,6 +13,10 @@     It is designed to be fast when it runs on 128-bit SIMD. It can be     compiled with either SSE2 and PowerPC AltiVec support, to take     advantage of these instructions.+    .+    > cabal install -fuse_sse2+    .+    On an x86 system, for performance win.     .     By default the period of the function is 2^19937-1, however, you can     compile in other defaults. Note that this algorithm on its own