random-1.1/0000755000000000000000000000000012406126363011024 5ustar0000000000000000random-1.1/.darcs-boring0000644000000000000000000000010712406126363013375 0ustar0000000000000000^dist(/|$) ^setup(/|$) ^GNUmakefile$ ^Makefile.local$ ^.depend(.bak)?$ random-1.1/.gitignore0000644000000000000000000000014412406126363013013 0ustar0000000000000000*~ Thumbs.db .DS_Store GNUmakefile dist-install/ ghc.mk dist .cabal-sandbox cabal.sandbox.config random-1.1/.travis.yml0000644000000000000000000000005712406126363013137 0ustar0000000000000000language: haskell ghc: - 7.4 - 7.6 - 7.8 random-1.1/CHANGELOG.md0000644000000000000000000000157512406126363012645 0ustar0000000000000000# 1.1 * breaking change to `randomIValInteger` to improve RNG quality and performance see https://github.com/haskell/random/pull/4 and ghc https://ghc.haskell.org/trac/ghc/ticket/8898 * correct documentation about generated range of Int32 sized values of type Int https://github.com/haskell/random/pull/7 * fix memory leaks by using strict fields and strict atomicModifyIORef' https://github.com/haskell/random/pull/8 related to ghc trac tickets #7936 and #4218 * support for base < 4.6 (which doesnt provide strict atomicModifyIORef') and integrating Travis CI support. https://github.com/haskell/random/pull/12 * fix C type in test suite https://github.com/haskell/random/pull/9 # 1.0.1.1 bump for overflow bug fixes # 1.0.1.2 bump for ticket 8704, build fusion # 1.0.1.0 bump for bug fixes, # 1.0.0.4 bumped version for float/double range bugfix random-1.1/LICENSE0000644000000000000000000000556612406126363012045 0ustar0000000000000000This library (libraries/base) is derived from code from two sources: * Code from the GHC project which is largely (c) The University of Glasgow, and distributable under a BSD-style license (see below), * Code from the Haskell 98 Report which is (c) Simon Peyton Jones and freely redistributable (but see the full license for restrictions). The full text of these licenses is reproduced below. Both of the licenses are BSD-style or compatible. ----------------------------------------------------------------------------- The Glasgow Haskell Compiler License Copyright 2004, The University Court of the University of Glasgow. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: - Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. - Neither name of the University nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY COURT OF THE UNIVERSITY OF GLASGOW AND THE CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY COURT OF THE UNIVERSITY OF GLASGOW OR THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ----------------------------------------------------------------------------- Code derived from the document "Report on the Programming Language Haskell 98", is distributed under the following license: Copyright (c) 2002 Simon Peyton Jones The authors intend this Report to belong to the entire Haskell community, and so we grant permission to copy and distribute it for any purpose, provided that it is reproduced in its entirety, including this Notice. Modified versions of this Report may also be copied and distributed for any purpose, provided that the modified version is clearly presented as such, and that it does not claim to be a definition of the Haskell 98 Language. ----------------------------------------------------------------------------- random-1.1/random.cabal0000644000000000000000000000322512406126363013272 0ustar0000000000000000name: random version: 1.1 license: BSD3 license-file: LICENSE maintainer: core-libraries-committee@haskell.org bug-reports: https://github.com/haskell/random/issues synopsis: random number library category: System description: This package provides a basic random number generation library, including the ability to split random number generators. extra-source-files: .travis.yml README.md CHANGELOG.md .gitignore .darcs-boring build-type: Simple -- cabal-version 1.8 needed because "the field 'build-depends: random' refers -- to a library which is defined within the same package" cabal-version: >= 1.8 Library exposed-modules: System.Random extensions: CPP GHC-Options: -O2 build-depends: base >= 3 && < 5, time source-repository head type: git location: http://git.haskell.org/packages/random.git -- To run the Test-Suite: -- $ cabal configure --enable-tests -- $ cabal test --show-details=always --test-options="+RTS -M1M -RTS" Test-Suite T7936 type: exitcode-stdio-1.0 main-is: T7936.hs hs-source-dirs: tests build-depends: base >= 3 && < 5, random ghc-options: -rtsopts -O2 Test-Suite TestRandomRs type: exitcode-stdio-1.0 main-is: TestRandomRs.hs hs-source-dirs: tests build-depends: base >= 3 && < 5, random ghc-options: -rtsopts -O2 -- TODO. Why does the following not work? --test-options: +RTS -M1M -RTS Test-Suite TestRandomIOs type: exitcode-stdio-1.0 main-is: TestRandomIOs.hs hs-source-dirs: tests build-depends: base >= 3 && < 5, random ghc-options: -rtsopts -O2 random-1.1/README.md0000644000000000000000000000163412406126363012307 0ustar0000000000000000The Haskell Standard Library -- Random Number Generation ======================================================== [![Build Status](https://secure.travis-ci.org/haskell/random.svg?branch=master)](http://travis-ci.org/haskell/random) This library provides a basic interface for (splittable) random number generators. The API documentation can be found here: http://hackage.haskell.org/package/random/docs/System-Random.html A module supplying this interface is required for Haskell 98 (but not Haskell 2010). An older [version] (http://www.haskell.org/ghc/docs/latest/html/libraries/haskell98/Random.html) of this library is included with GHC in the haskell98 package. This newer version, with compatible api, is included in the [Haskell Platform] (http://www.haskell.org/platform/contents.html). Please report bugs in the Github [issue tracker] (https://github.com/haskell/random/issues) (no longer in the GHC trac). random-1.1/Setup.hs0000644000000000000000000000012712406126363012460 0ustar0000000000000000module Main (main) where import Distribution.Simple main :: IO () main = defaultMain random-1.1/System/0000755000000000000000000000000012406126363012310 5ustar0000000000000000random-1.1/System/Random.hs0000644000000000000000000005274012406126363014074 0ustar0000000000000000#if __GLASGOW_HASKELL__ >= 701 {-# LANGUAGE Trustworthy #-} #endif ----------------------------------------------------------------------------- -- | -- Module : System.Random -- Copyright : (c) The University of Glasgow 2001 -- License : BSD-style (see the file LICENSE in the 'random' repository) -- -- Maintainer : libraries@haskell.org -- Stability : stable -- Portability : portable -- -- This library deals with the common task of pseudo-random number -- generation. The library makes it possible to generate repeatable -- results, by starting with a specified initial random number generator, -- or to get different results on each run by using the system-initialised -- generator or by supplying a seed from some other source. -- -- The library is split into two layers: -- -- * A core /random number generator/ provides a supply of bits. -- The class 'RandomGen' provides a common interface to such generators. -- The library provides one instance of 'RandomGen', the abstract -- data type 'StdGen'. Programmers may, of course, supply their own -- instances of 'RandomGen'. -- -- * The class 'Random' provides a way to extract values of a particular -- type from a random number generator. For example, the 'Float' -- instance of 'Random' allows one to generate random values of type -- 'Float'. -- -- This implementation uses the Portable Combined Generator of L'Ecuyer -- ["System.Random\#LEcuyer"] for 32-bit computers, transliterated by -- Lennart Augustsson. It has a period of roughly 2.30584e18. -- ----------------------------------------------------------------------------- #include "MachDeps.h" module System.Random ( -- $intro -- * Random number generators #ifdef ENABLE_SPLITTABLEGEN RandomGen(next, genRange) , SplittableGen(split) #else RandomGen(next, genRange, split) #endif -- ** Standard random number generators , StdGen , mkStdGen -- ** The global random number generator -- $globalrng , getStdRandom , getStdGen , setStdGen , newStdGen -- * Random values of various types , Random ( random, randomR, randoms, randomRs, randomIO, randomRIO ) -- * References -- $references ) where import Prelude import Data.Bits import Data.Int import Data.Word import Foreign.C.Types #ifdef __NHC__ import CPUTime ( getCPUTime ) import Foreign.Ptr ( Ptr, nullPtr ) import Foreign.C ( CTime, CUInt ) #else import System.CPUTime ( getCPUTime ) import Data.Time ( getCurrentTime, UTCTime(..) ) import Data.Ratio ( numerator, denominator ) #endif import Data.Char ( isSpace, chr, ord ) import System.IO.Unsafe ( unsafePerformIO ) import Data.IORef ( IORef, newIORef, readIORef, writeIORef ) #if MIN_VERSION_base (4,6,0) import Data.IORef ( atomicModifyIORef' ) #else import Data.IORef ( atomicModifyIORef ) #endif import Numeric ( readDec ) #ifdef __GLASGOW_HASKELL__ import GHC.Exts ( build ) #else -- | A dummy variant of build without fusion. {-# INLINE build #-} build :: ((a -> [a] -> [a]) -> [a] -> [a]) -> [a] build g = g (:) [] #endif #if !MIN_VERSION_base (4,6,0) atomicModifyIORef' :: IORef a -> (a -> (a,b)) -> IO b atomicModifyIORef' ref f = do b <- atomicModifyIORef ref (\x -> let (a, b) = f x in (a, a `seq` b)) b `seq` return b #endif -- The standard nhc98 implementation of Time.ClockTime does not match -- the extended one expected in this module, so we lash-up a quick -- replacement here. #ifdef __NHC__ foreign import ccall "time.h time" readtime :: Ptr CTime -> IO CTime getTime :: IO (Integer, Integer) getTime = do CTime t <- readtime nullPtr; return (toInteger t, 0) #else getTime :: IO (Integer, Integer) getTime = do utc <- getCurrentTime let daytime = toRational $ utctDayTime utc return $ quotRem (numerator daytime) (denominator daytime) #endif -- | The class 'RandomGen' provides a common interface to random number -- generators. -- #ifdef ENABLE_SPLITTABLEGEN -- Minimal complete definition: 'next'. #else -- Minimal complete definition: 'next' and 'split'. #endif class RandomGen g where -- |The 'next' operation returns an 'Int' that is uniformly distributed -- in the range returned by 'genRange' (including both end points), -- and a new generator. next :: g -> (Int, g) -- |The 'genRange' operation yields the range of values returned by -- the generator. -- -- It is required that: -- -- * If @(a,b) = 'genRange' g@, then @a < b@. -- -- * 'genRange' always returns a pair of defined 'Int's. -- -- The second condition ensures that 'genRange' cannot examine its -- argument, and hence the value it returns can be determined only by the -- instance of 'RandomGen'. That in turn allows an implementation to make -- a single call to 'genRange' to establish a generator's range, without -- being concerned that the generator returned by (say) 'next' might have -- a different range to the generator passed to 'next'. -- -- The default definition spans the full range of 'Int'. genRange :: g -> (Int,Int) -- default method genRange _ = (minBound, maxBound) #ifdef ENABLE_SPLITTABLEGEN -- | The class 'SplittableGen' proivides a way to specify a random number -- generator that can be split into two new generators. class SplittableGen g where #endif -- |The 'split' operation allows one to obtain two distinct random number -- generators. This is very useful in functional programs (for example, when -- passing a random number generator down to recursive calls), but very -- little work has been done on statistically robust implementations of -- 'split' (["System.Random\#Burton", "System.Random\#Hellekalek"] -- are the only examples we know of). split :: g -> (g, g) {- | The 'StdGen' instance of 'RandomGen' has a 'genRange' of at least 30 bits. The result of repeatedly using 'next' should be at least as statistically robust as the /Minimal Standard Random Number Generator/ described by ["System.Random\#Park", "System.Random\#Carta"]. Until more is known about implementations of 'split', all we require is that 'split' deliver generators that are (a) not identical and (b) independently robust in the sense just given. The 'Show' and 'Read' instances of 'StdGen' provide a primitive way to save the state of a random number generator. It is required that @'read' ('show' g) == g@. In addition, 'reads' may be used to map an arbitrary string (not necessarily one produced by 'show') onto a value of type 'StdGen'. In general, the 'Read' instance of 'StdGen' has the following properties: * It guarantees to succeed on any string. * It guarantees to consume only a finite portion of the string. * Different argument strings are likely to result in different results. -} data StdGen = StdGen !Int32 !Int32 instance RandomGen StdGen where next = stdNext genRange _ = stdRange #ifdef ENABLE_SPLITTABLEGEN instance SplittableGen StdGen where #endif split = stdSplit instance Show StdGen where showsPrec p (StdGen s1 s2) = showsPrec p s1 . showChar ' ' . showsPrec p s2 instance Read StdGen where readsPrec _p = \ r -> case try_read r of r'@[_] -> r' _ -> [stdFromString r] -- because it shouldn't ever fail. where try_read r = do (s1, r1) <- readDec (dropWhile isSpace r) (s2, r2) <- readDec (dropWhile isSpace r1) return (StdGen s1 s2, r2) {- If we cannot unravel the StdGen from a string, create one based on the string given. -} stdFromString :: String -> (StdGen, String) stdFromString s = (mkStdGen num, rest) where (cs, rest) = splitAt 6 s num = foldl (\a x -> x + 3 * a) 1 (map ord cs) {- | The function 'mkStdGen' provides an alternative way of producing an initial generator, by mapping an 'Int' into a generator. Again, distinct arguments should be likely to produce distinct generators. -} mkStdGen :: Int -> StdGen -- why not Integer ? mkStdGen s = mkStdGen32 $ fromIntegral s {- From ["System.Random\#LEcuyer"]: "The integer variables s1 and s2 ... must be initialized to values in the range [1, 2147483562] and [1, 2147483398] respectively." -} mkStdGen32 :: Int32 -> StdGen mkStdGen32 sMaybeNegative = StdGen (s1+1) (s2+1) where -- We want a non-negative number, but we can't just take the abs -- of sMaybeNegative as -minBound == minBound. s = sMaybeNegative .&. maxBound (q, s1) = s `divMod` 2147483562 s2 = q `mod` 2147483398 createStdGen :: Integer -> StdGen createStdGen s = mkStdGen32 $ fromIntegral s {- | With a source of random number supply in hand, the 'Random' class allows the programmer to extract random values of a variety of types. Minimal complete definition: 'randomR' and 'random'. -} class Random a where -- | Takes a range /(lo,hi)/ and a random number generator -- /g/, and returns a random value uniformly distributed in the closed -- interval /[lo,hi]/, together with a new generator. It is unspecified -- what happens if /lo>hi/. For continuous types there is no requirement -- that the values /lo/ and /hi/ are ever produced, but they may be, -- depending on the implementation and the interval. randomR :: RandomGen g => (a,a) -> g -> (a,g) -- | The same as 'randomR', but using a default range determined by the type: -- -- * For bounded types (instances of 'Bounded', such as 'Char'), -- the range is normally the whole type. -- -- * For fractional types, the range is normally the semi-closed interval -- @[0,1)@. -- -- * For 'Integer', the range is (arbitrarily) the range of 'Int'. random :: RandomGen g => g -> (a, g) -- | Plural variant of 'randomR', producing an infinite list of -- random values instead of returning a new generator. {-# INLINE randomRs #-} randomRs :: RandomGen g => (a,a) -> g -> [a] randomRs ival g = build (\cons _nil -> buildRandoms cons (randomR ival) g) -- | Plural variant of 'random', producing an infinite list of -- random values instead of returning a new generator. {-# INLINE randoms #-} randoms :: RandomGen g => g -> [a] randoms g = build (\cons _nil -> buildRandoms cons random g) -- | A variant of 'randomR' that uses the global random number generator -- (see "System.Random#globalrng"). randomRIO :: (a,a) -> IO a randomRIO range = getStdRandom (randomR range) -- | A variant of 'random' that uses the global random number generator -- (see "System.Random#globalrng"). randomIO :: IO a randomIO = getStdRandom random -- | Produce an infinite list-equivalent of random values. {-# INLINE buildRandoms #-} buildRandoms :: RandomGen g => (a -> as -> as) -- ^ E.g. '(:)' but subject to fusion -> (g -> (a,g)) -- ^ E.g. 'random' -> g -- ^ A 'RandomGen' instance -> as buildRandoms cons rand = go where -- The seq fixes part of #4218 and also makes fused Core simpler. go g = x `seq` (x `cons` go g') where (x,g') = rand g instance Random Integer where randomR ival g = randomIvalInteger ival g random g = randomR (toInteger (minBound::Int), toInteger (maxBound::Int)) g instance Random Int where randomR = randomIvalIntegral; random = randomBounded instance Random Int8 where randomR = randomIvalIntegral; random = randomBounded instance Random Int16 where randomR = randomIvalIntegral; random = randomBounded instance Random Int32 where randomR = randomIvalIntegral; random = randomBounded instance Random Int64 where randomR = randomIvalIntegral; random = randomBounded #ifndef __NHC__ -- Word is a type synonym in nhc98. instance Random Word where randomR = randomIvalIntegral; random = randomBounded #endif instance Random Word8 where randomR = randomIvalIntegral; random = randomBounded instance Random Word16 where randomR = randomIvalIntegral; random = randomBounded instance Random Word32 where randomR = randomIvalIntegral; random = randomBounded instance Random Word64 where randomR = randomIvalIntegral; random = randomBounded instance Random CChar where randomR = randomIvalIntegral; random = randomBounded instance Random CSChar where randomR = randomIvalIntegral; random = randomBounded instance Random CUChar where randomR = randomIvalIntegral; random = randomBounded instance Random CShort where randomR = randomIvalIntegral; random = randomBounded instance Random CUShort where randomR = randomIvalIntegral; random = randomBounded instance Random CInt where randomR = randomIvalIntegral; random = randomBounded instance Random CUInt where randomR = randomIvalIntegral; random = randomBounded instance Random CLong where randomR = randomIvalIntegral; random = randomBounded instance Random CULong where randomR = randomIvalIntegral; random = randomBounded instance Random CPtrdiff where randomR = randomIvalIntegral; random = randomBounded instance Random CSize where randomR = randomIvalIntegral; random = randomBounded instance Random CWchar where randomR = randomIvalIntegral; random = randomBounded instance Random CSigAtomic where randomR = randomIvalIntegral; random = randomBounded instance Random CLLong where randomR = randomIvalIntegral; random = randomBounded instance Random CULLong where randomR = randomIvalIntegral; random = randomBounded instance Random CIntPtr where randomR = randomIvalIntegral; random = randomBounded instance Random CUIntPtr where randomR = randomIvalIntegral; random = randomBounded instance Random CIntMax where randomR = randomIvalIntegral; random = randomBounded instance Random CUIntMax where randomR = randomIvalIntegral; random = randomBounded instance Random Char where randomR (a,b) g = case (randomIvalInteger (toInteger (ord a), toInteger (ord b)) g) of (x,g') -> (chr x, g') random g = randomR (minBound,maxBound) g instance Random Bool where randomR (a,b) g = case (randomIvalInteger (bool2Int a, bool2Int b) g) of (x, g') -> (int2Bool x, g') where bool2Int :: Bool -> Integer bool2Int False = 0 bool2Int True = 1 int2Bool :: Int -> Bool int2Bool 0 = False int2Bool _ = True random g = randomR (minBound,maxBound) g {-# INLINE randomRFloating #-} randomRFloating :: (Fractional a, Num a, Ord a, Random a, RandomGen g) => (a, a) -> g -> (a, g) randomRFloating (l,h) g | l>h = randomRFloating (h,l) g | otherwise = let (coef,g') = random g in (2.0 * (0.5*l + coef * (0.5*h - 0.5*l)), g') -- avoid overflow instance Random Double where randomR = randomRFloating random rng = case random rng of (x,rng') -> -- We use 53 bits of randomness corresponding to the 53 bit significand: ((fromIntegral (mask53 .&. (x::Int64)) :: Double) / fromIntegral twoto53, rng') where twoto53 = (2::Int64) ^ (53::Int64) mask53 = twoto53 - 1 instance Random Float where randomR = randomRFloating random rng = -- TODO: Faster to just use 'next' IF it generates enough bits of randomness. case random rng of (x,rng') -> -- We use 24 bits of randomness corresponding to the 24 bit significand: ((fromIntegral (mask24 .&. (x::Int32)) :: Float) / fromIntegral twoto24, rng') -- Note, encodeFloat is another option, but I'm not seeing slightly -- worse performance with the following [2011.06.25]: -- (encodeFloat rand (-24), rng') where mask24 = twoto24 - 1 twoto24 = (2::Int32) ^ (24::Int32) -- CFloat/CDouble are basically the same as a Float/Double: instance Random CFloat where randomR = randomRFloating random rng = case random rng of (x,rng') -> (realToFrac (x::Float), rng') instance Random CDouble where randomR = randomRFloating -- A MYSTERY: -- Presently, this is showing better performance than the Double instance: -- (And yet, if the Double instance uses randomFrac then its performance is much worse!) random = randomFrac -- random rng = case random rng of -- (x,rng') -> (realToFrac (x::Double), rng') mkStdRNG :: Integer -> IO StdGen mkStdRNG o = do ct <- getCPUTime (sec, psec) <- getTime return (createStdGen (sec * 12345 + psec + ct + o)) randomBounded :: (RandomGen g, Random a, Bounded a) => g -> (a, g) randomBounded = randomR (minBound, maxBound) -- The two integer functions below take an [inclusive,inclusive] range. randomIvalIntegral :: (RandomGen g, Integral a) => (a, a) -> g -> (a, g) randomIvalIntegral (l,h) = randomIvalInteger (toInteger l, toInteger h) {-# SPECIALIZE randomIvalInteger :: (Num a) => (Integer, Integer) -> StdGen -> (a, StdGen) #-} randomIvalInteger :: (RandomGen g, Num a) => (Integer, Integer) -> g -> (a, g) randomIvalInteger (l,h) rng | l > h = randomIvalInteger (h,l) rng | otherwise = case (f 1 0 rng) of (v, rng') -> (fromInteger (l + v `mod` k), rng') where (genlo, genhi) = genRange rng b = fromIntegral genhi - fromIntegral genlo + 1 -- Probabilities of the most likely and least likely result -- will differ at most by a factor of (1 +- 1/q). Assuming the RandomGen -- is uniform, of course -- On average, log q / log b more random values will be generated -- than the minimum q = 1000 k = h - l + 1 magtgt = k * q -- generate random values until we exceed the target magnitude f mag v g | mag >= magtgt = (v, g) | otherwise = v' `seq`f (mag*b) v' g' where (x,g') = next g v' = (v * b + (fromIntegral x - fromIntegral genlo)) -- The continuous functions on the other hand take an [inclusive,exclusive) range. randomFrac :: (RandomGen g, Fractional a) => g -> (a, g) randomFrac = randomIvalDouble (0::Double,1) realToFrac randomIvalDouble :: (RandomGen g, Fractional a) => (Double, Double) -> (Double -> a) -> g -> (a, g) randomIvalDouble (l,h) fromDouble rng | l > h = randomIvalDouble (h,l) fromDouble rng | otherwise = case (randomIvalInteger (toInteger (minBound::Int32), toInteger (maxBound::Int32)) rng) of (x, rng') -> let scaled_x = fromDouble (0.5*l + 0.5*h) + -- previously (l+h)/2, overflowed fromDouble ((0.5*h - 0.5*l) / (0.5 * realToFrac int32Count)) * -- avoid overflow fromIntegral (x::Int32) in (scaled_x, rng') int32Count :: Integer int32Count = toInteger (maxBound::Int32) - toInteger (minBound::Int32) + 1 -- GHC ticket #3982 stdRange :: (Int,Int) stdRange = (1, 2147483562) stdNext :: StdGen -> (Int, StdGen) -- Returns values in the range stdRange stdNext (StdGen s1 s2) = (fromIntegral z', StdGen s1'' s2'') where z' = if z < 1 then z + 2147483562 else z z = s1'' - s2'' k = s1 `quot` 53668 s1' = 40014 * (s1 - k * 53668) - k * 12211 s1'' = if s1' < 0 then s1' + 2147483563 else s1' k' = s2 `quot` 52774 s2' = 40692 * (s2 - k' * 52774) - k' * 3791 s2'' = if s2' < 0 then s2' + 2147483399 else s2' stdSplit :: StdGen -> (StdGen, StdGen) stdSplit std@(StdGen s1 s2) = (left, right) where -- no statistical foundation for this! left = StdGen new_s1 t2 right = StdGen t1 new_s2 new_s1 | s1 == 2147483562 = 1 | otherwise = s1 + 1 new_s2 | s2 == 1 = 2147483398 | otherwise = s2 - 1 StdGen t1 t2 = snd (next std) -- The 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, for example, by using the time of day, or Linux's kernel random number generator. To get deterministic behaviour, use 'setStdGen'. -} -- |Sets the global random number generator. setStdGen :: StdGen -> IO () setStdGen sgen = writeIORef theStdGen sgen -- |Gets the global random number generator. getStdGen :: IO StdGen getStdGen = readIORef theStdGen theStdGen :: IORef StdGen theStdGen = unsafePerformIO $ do rng <- mkStdRNG 0 newIORef rng -- |Applies 'split' to the current global random generator, -- updates it with one of the results, and returns the other. newStdGen :: IO StdGen newStdGen = atomicModifyIORef' theStdGen split {- |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 = getStdRandom (randomR (1,6)) -} getStdRandom :: (StdGen -> (a,StdGen)) -> IO a getStdRandom f = atomicModifyIORef' theStdGen (swap . f) where swap (v,g) = (g,v) {- $references 1. FW #Burton# Burton and RL Page, /Distributed random number generation/, Journal of Functional Programming, 2(2):203-212, April 1992. 2. SK #Park# Park, and KW Miller, /Random number generators - good ones are hard to find/, Comm ACM 31(10), Oct 1988, pp1192-1201. 3. DG #Carta# Carta, /Two fast implementations of the minimal standard random number generator/, Comm ACM, 33(1), Jan 1990, pp87-88. 4. P #Hellekalek# Hellekalek, /Don\'t trust parallel Monte Carlo/, Department of Mathematics, University of Salzburg, , 1998. 5. Pierre #LEcuyer# L'Ecuyer, /Efficient and portable combined random number generators/, Comm ACM, 31(6), Jun 1988, pp742-749. The Web site is a great source of information. -} random-1.1/tests/0000755000000000000000000000000012406126363012166 5ustar0000000000000000random-1.1/tests/T7936.hs0000644000000000000000000000046312406126363013261 0ustar0000000000000000-- Test for ticket #7936: -- https://ghc.haskell.org/trac/ghc/ticket/7936 -- -- Used to fail with: -- -- $ cabal test T7936 --test-options="+RTS -M1M -RTS" -- T7936: Heap exhausted; module Main where import System.Random (newStdGen) import Control.Monad (replicateM_) main = replicateM_ 100000 newStdGen random-1.1/tests/TestRandomIOs.hs0000644000000000000000000000107212406126363015215 0ustar0000000000000000-- Test for ticket #4218 (TestRandomIOs): -- https://ghc.haskell.org/trac/ghc/ticket/4218 -- -- Used to fail with: -- -- $ cabal test TestRandomIOs --test-options="+RTS -M1M -RTS" -- TestRandomIOs: Heap exhausted; module Main where import Control.Monad (replicateM) import System.Random (randomIO) -- Build a list of 5000 random ints in memory (IO Monad is strict), and print -- the last one. -- Should use less than 1Mb of heap space, or we are generating a list of -- unevaluated thunks. main = do rs <- replicateM 5000 randomIO :: IO [Int] print $ last rs random-1.1/tests/TestRandomRs.hs0000644000000000000000000000121012406126363015101 0ustar0000000000000000-- Test for ticket #4218 (TestRandomRs): -- https://ghc.haskell.org/trac/ghc/ticket/4218 -- -- Fixed together with ticket #8704 -- https://ghc.haskell.org/trac/ghc/ticket/8704 -- Commit 4695ffa366f659940369f05e419a4f2249c3a776 -- -- Used to fail with: -- -- $ cabal test TestRandomRs --test-options="+RTS -M1M -RTS" -- TestRandomRs: Heap exhausted; module Main where import Control.Monad (liftM, replicateM) import System.Random (randomRs, getStdGen) -- Return the five-thousandth random number: -- Should run in constant space (< 1Mb heap). main = do n <- (last . take 5000 . randomRs (0, 1000000)) `liftM` getStdGen print (n::Integer)