buffon-machines 1.0.0.0 → 1.1.0.0

raw patch · 2 files changed

+31/−34 lines, 2 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• Data/Buffon/Machine.hs +30/−33
• buffon-machines.cabal +1/−1

@@ -45,7 +45,7 @@      in Algorithms and Complexity: New Directions and Recent Results,      Academic Press, (1976)  -}-{-# LANGUAGE TupleSections, BangPatterns, DeriveLift #-}+{-# LANGUAGE BangPatterns, DeriveLift #-} module Data.Buffon.Machine     ( -- * Buffon machines and related utilities.       Rand(..), empty, init@@ -61,7 +61,7 @@     , flip, flip'      -- * Bernoulli variable generators.-    , dyadic, rational, real+    , rational, real      -- * Buffon machine combinators.     , repeat, cond, neg@@ -105,9 +105,9 @@  -- | 32-bit buffered random bit generator (RBG). data Rand g =-    Rand { buffer  :: Word32 -- ^ Generator buffer.-         , counter :: Int    -- ^ Number of consumed buffer bits.-         , oracle  :: g      -- ^ Random bit oracle.+    Rand { buffer  :: !Word32 -- ^ Generator buffer.+         , counter :: !Int    -- ^ Number of consumed buffer bits.+         , oracle  :: !g      -- ^ Random bit oracle.          }  -- | Checks if the given RBG is empty or not.@@ -117,10 +117,10 @@  -- | A fresh RBG. init :: RandomGen g => g -> Rand g-init g = let (x, g') = random g-             in Rand { buffer  = x-                     , counter = 0-                     , oracle  = g' }+init g = case random g of+          (x, g') -> Rand { buffer  = x+                          , counter = 0+                          , oracle  = g' }  -- | Computations consuming random bits using RBGs. --   Note that the implementation is essentially a State monad,@@ -136,11 +136,11 @@     (<*>) = ap  instance Monad (BuffonMachine g) where-    return x = BuffonMachine (x,)+    return x = BuffonMachine $ \ !rng -> (x, rng)     (BuffonMachine f) >>= h =-        BuffonMachine $ \rng ->-            let (x, rng') = f rng-             in runR (h x) rng'+        BuffonMachine $ \ !rng ->+            case f rng of+              (x, !rng') -> runR (h x) rng'  -- | Runs the given Buffon machine within the IO monad --    using StdGen as its random bit oracle.@@ -203,7 +203,7 @@ histogramIO m n = runRIO (histogram m n) >>= print  mkFlip :: Rand g -> (Bool, Rand g)-mkFlip rng =+mkFlip !rng =     (testBit (buffer rng) (counter rng), -- test the respective bit.         rng { counter = succ (counter rng) }) @@ -223,7 +223,7 @@ -- | Random coin flip. Note that the implementation --   handles the regeneration of the RBG, see 'Rand'. flip :: RandomGen g => Bern g-flip = BuffonMachine $ \rng ->+flip = BuffonMachine $ \ !rng ->     mkFlip $ if empty rng then init (oracle rng)                           else rng @@ -241,12 +241,6 @@       (True, False) -> return True       _             -> flip' --- | Generates all 2^n boolean strings of length n.-genStream :: Int -> [[Bool]]-genStream 0 = [[]]-genStream !n =  map (False :) (genStream $ pred n)-             ++ map (True :) (genStream $ pred n)- -- | Evaluates the given Bernoulli variable n times --   and returns a list of resulting values. repeat :: RandomGen g@@ -258,13 +252,6 @@     bs <- repeat (pred n) m     return (b : bs) --- | Bernoulli variable machine with dyadic parameter λ = s/(2^t).-dyadic :: RandomGen g => Int -> Int -> Bern g-dyadic s t = do-    let ps = take s (genStream t)-    bs <- repeat t flip-    return $ bs `elem` ps- -- | Given parameters a < b, both positive, returns a Bernoulli --   variable with rational parameter λ = a/b. Note: Implements --   the algorithm 'Bernoulli' described by J. Lumbroso.@@ -639,11 +626,21 @@  -- | Draws a discrete variable according --   to the given decision tree.-choice :: (Num a, Enum a, RandomGen g)+choice :: RandomGen g        => DecisionTree a -> BuffonMachine g a -choice (Decision n) = return n-choice (Toss lt rt) = do+choice !x = do     heads <- flip-    if heads then choice rt-             else choice lt+    choice' heads x++choice' :: RandomGen g+        =>  Bool -> DecisionTree a -> BuffonMachine g a++choice' _ (Decision n) = return n+choice' True (Toss _ rt) = do+    heads <- flip+    choice' heads rt++choice' False (Toss lt _) = do+    heads <- flip+    choice' heads lt

@@ -1,5 +1,5 @@ name:           buffon-machines-version:        1.0.0.0+version:        1.1.0.0 synopsis:       Perfect simulation of discrete random variables description:    Monadic implementation of Buffon machines meant for perfect simulation of discrete random variables homepage:       https://github.com/maciej-bendkowski/buffon-machines#readme