diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,30 @@ +Copyright (c)2010, Alexey Khudyakov + +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 the name of Alexey Khudyakov nor the names of other + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 COPYRIGHT +OWNER OR 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. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/System/Random/MWC/Monad.hs b/System/Random/MWC/Monad.hs new file mode 100644 --- /dev/null +++ b/System/Random/MWC/Monad.hs @@ -0,0 +1,127 @@ +module System.Random.MWC.Monad ( -- * Random monad + Rand + , RandIO + , asRandIO + , RandST + , asRandST + , Seed + , runRand + , runWithSeed + , runWithVector + , runWithSystemRandom + -- * Random numbers generation + , toRand + , uniform + , uniformR + , standard + , normal + -- * Seed management + , save + ) where + +import Control.Applicative +import Control.Monad (ap) +import Control.Monad.ST (ST) +import Control.Monad.Primitive (PrimMonad, PrimState) + +import Data.Vector.Unboxed (Vector) +import Data.Word (Word32) + +import qualified System.Random.MWC as MWC +import System.Random.MWC (Gen,Variate,Seed) + +---------------------------------------------------------------- + +-- | Random monad for mwc-random package +newtype Rand m a = Rand { + -- | Run random monad + runRand :: Gen (PrimState m) -> m a + } + +-- | Type synonim for ST-based Rand monad +type RandST s a = Rand (ST s) a + +-- | Fix type of monad to ST +asRandST :: RandST s a -> RandST s a +asRandST = id +{-# INLINE asRandST #-} + +-- | Type synonim for IO-based Rand monad +type RandIO a = Rand IO a + +-- | Fix type of monad to IO +asRandIO :: RandIO a -> RandIO a +asRandIO = id +{-# INLINE asRandIO #-} + +-- | Run monad using fixed seed +runWithCreate :: PrimMonad m => Rand m a -> m a +runWithCreate m = runRand m =<< MWC.create +{-# INLINE runWithCreate #-} + +-- | By creating seed from vector of values +runWithVector :: PrimMonad m => Rand m a -> Vector Word32 -> m a +runWithVector m v = runRand m =<< MWC.initialize v +{-# INLINE runWithVector #-} + +-- | Run monad using seed +runWithSeed :: PrimMonad m => Seed -> Rand m a -> m a +runWithSeed seed m = runRand m =<< MWC.restore seed +{-# INLINE runWithSeed #-} + +-- | Run monad using system random +runWithSystemRandom :: PrimMonad m => Rand m a -> IO a +runWithSystemRandom = MWC.withSystemRandom . runRand +{-# INLINE runWithSystemRandom #-} + +instance PrimMonad m => Functor (Rand m) where + fmap f (Rand rnd) = Rand $ \g -> (return . f) =<< (rnd g) + {-# INLINE fmap #-} + +instance PrimMonad m => Monad (Rand m) where + return x = Rand (\_ -> return x) + (Rand rnd) >>= f = Rand $ \g -> (\x -> runRand (f x) g) =<< rnd g + {-# INLINE return #-} + {-# INLINE (>>=) #-} + +instance (PrimMonad m) => Applicative (Rand m) where + pure = return + (<*>) = ap + {-# INLINE pure #-} + {-# INLINE (<*>) #-} + +---------------------------------------------------------------- + +-- | Convert function to Rand monad +toRand :: PrimMonad m => (Gen (PrimState m) -> m a) -> Rand m a +toRand = Rand +{-# INLINE toRand #-} + +-- | Uniformly distributed values +uniform :: (PrimMonad m, Variate a) => Rand m a +uniform = Rand MWC.uniform +{-# INLINE uniform #-} + +-- | Uniformly distributed values in range +uniformR :: (PrimMonad m, Variate a) => (a,a) -> Rand m a +uniformR rng = Rand (MWC.uniformR rng) +{-# INLINE uniformR #-} + +-- | Normally distributed variables with mean 0 and 1 standard deviation +standard :: PrimMonad m => Rand m Double +standard = Rand MWC.normal +{-# INLINE normal #-} + +-- | Normally distributed variable +normal :: PrimMonad m => + Double -- Mean + -> Double -- Variance + -> Rand m Double +normal m s = (+ m) . (* s) <$> standard +{-# INLINE standard #-} + +---------------------------------------------------------------- + +-- | Save current seed for future reuse +save :: PrimMonad m => Rand m Seed +save = Rand MWC.save diff --git a/mwc-random-monad.cabal b/mwc-random-monad.cabal new file mode 100644 --- /dev/null +++ b/mwc-random-monad.cabal @@ -0,0 +1,23 @@ +Name: mwc-random-monad +Version: 0.1 +Synopsis: Monadic interface for mwc-random +License: BSD3 +License-file: LICENSE +Author: Alexey Khudyakov +Maintainer: Alexey Khudyakov +Category: Math, Statistics +Build-type: Simple +Cabal-version: >=1.6 +Description: + Simple monadit interface for mwc-random. + +Library + build-depends: base >= 3 && < 5, + primitive, + vector >= 0.6.0.2, + mwc-random >= 0.8 + Exposed-modules: System.Random.MWC.Monad + +source-repository head + type: mercurial + location: http://bitbucket.org/Shimuuar/mwc-random-monad