Get rid of Samplable

generic-boltzmann-brain.cabal

@@ -26,7 +26,7 @@ source-repository head
 
 library
   exposed-modules:
-      Data.Boltzmann.Samplable
+      Data.Boltzmann.Distribution
       Data.Boltzmann.Sampler
       Data.Boltzmann.Sampler.TH
       Data.Boltzmann.System
@@ -140,7 +140,7 @@ test-suite generic-boltzmann-brain-test
   type: exitcode-stdio-1.0
   main-is: Spec.hs
   other-modules:
-      Test.Unit.Samplable
+      Test.Unit.Distribution
       Paths_generic_boltzmann_brain
   hs-source-dirs:
       test

src/Data/Boltzmann/Distribution.hs

@@ -1,7 +1,6 @@
 {-# LANGUAGE TemplateHaskell #-}
 
-module Data.Boltzmann.Samplable (
-  Samplable (..),
+module Data.Boltzmann.Distribution (
   Distribution (..),
   choice,
 ) where
@@ -13,11 +12,7 @@ import System.Random (RandomGen, StdGen)
 import System.Random.SplitMix (SMGen)
 import Prelude hiding (null)
 
-class Samplable a where
-  distribution :: Distribution a
-  weight :: a -> Int
-
-newtype Distribution a = Distribution {unDistribution :: Vector Int}
+newtype Distribution = Distribution {unDistribution :: Vector Int}
   deriving stock (Show)
 
 deriveLift ''Distribution
@@ -25,18 +20,18 @@ deriveLift ''Distribution
 -- |
 --  Given a compact discrete distribution generating tree (in vector form)
 --  computes a discrete random variable following that distribution.
-choice :: RandomGen g => Distribution a -> Discrete g
+choice :: RandomGen g => Distribution -> Discrete g
 choice enc
-  | null (unDistribution enc) = return 0
+  | null (unDistribution enc) = pure 0
   | otherwise = choice' enc 0
-{-# SPECIALIZE choice :: Distribution a -> Discrete SMGen #-}
-{-# SPECIALIZE choice :: Distribution a -> Discrete StdGen #-}
+{-# SPECIALIZE choice :: Distribution -> Discrete SMGen #-}
+{-# SPECIALIZE choice :: Distribution -> Discrete StdGen #-}
 
-choice' :: RandomGen g => Distribution a -> Int -> Discrete g
+choice' :: RandomGen g => Distribution -> Int -> Discrete g
 choice' enc c = do
   h <- getBit
   let b = fromEnum h
   let c' = unDistribution enc ! (c + b)
   if unDistribution enc ! c' < 0
-    then return $ -(1 + unDistribution enc ! c')
+    then pure $ -(1 + unDistribution enc ! c')
     else choice' enc c'

src/Data/Boltzmann/Sampler/TH.hs

@@ -19,7 +19,7 @@ import Data.Map (Map)
 import qualified Data.Map.Strict as Map
 
 import Control.Monad (forM)
-import Data.Boltzmann.Samplable (Distribution)
+import Data.Boltzmann.Distribution (Distribution)
 import Data.Boltzmann.System (
   Distributions (Distributions, listTypeDdgs, regTypeDdgs),
   System (targetType, weights),
@@ -72,7 +72,7 @@ idResolver :: SynonymResolver
 idResolver = MkSynonymResolver $ pure . coerce
 
 newtype TypeDistributions a = MkTypeDistributions
-  { unTypeDistributions :: TypeName -> Q (Distribution a)
+  { unTypeDistributions :: TypeName -> Q Distribution
   }
 
 mkTypeDistributions :: Distributions a -> TypeDistributions a
@@ -85,7 +85,7 @@ mkTypeDistributions Distributions {regTypeDdgs} =
           "Missing type constructor distribution for " ++ show n
 
 newtype ListTypeDistributions a = MkListTypeDistributions
-  { unListTypeDistributions :: TypeName -> Q (Distribution a)
+  { unListTypeDistributions :: TypeName -> Q Distribution
   }
 
 mkListTypeDistributions :: Distributions a -> ListTypeDistributions a

src/Data/Boltzmann/System.hs

@@ -10,7 +10,7 @@ module Data.Boltzmann.System (
 import Language.Haskell.TH.Syntax (Name, Type (AppT, ConT, ListT))
 
 import Control.Monad (foldM, forM, replicateM)
-import Data.Boltzmann.Samplable (Distribution (Distribution))
+import Data.Boltzmann.Distribution (Distribution (Distribution))
 import qualified Data.Map as Map
 import Data.Map.Strict (Map)
 import Data.Maybe (fromJust, fromMaybe)
@@ -122,7 +122,7 @@ mkMarkingVariables sys = do
     mapM
       ( \(cons, freq) -> do
           x <- variable' $ fromIntegral freq
-          return (cons, x)
+          pure (cons, x)
       )
       (frequencies sys)
 
@@ -172,8 +172,8 @@ defaults Nothing = 1
 defaults (Just (Let x)) = x
 
 data Distributions a = Distributions
-  { regTypeDdgs :: Map Name (Distribution a)
-  , listTypeDdgs :: Map Name (Distribution a)
+  { regTypeDdgs :: Map Name Distribution
+  , listTypeDdgs :: Map Name Distribution
   }
   deriving stock (Show)
 

src/Data/Boltzmann/System/TH.hs

@@ -9,7 +9,7 @@ import qualified Data.Set as Set
 import Control.Monad (forM, guard)
 import Control.Monad.Trans (MonadTrans (lift))
 import Control.Monad.Trans.Reader (ReaderT (runReaderT), asks)
-import Data.Boltzmann.Samplable (Distribution, choice)
+import Data.Boltzmann.Distribution (Distribution, choice)
 import Data.Boltzmann.Sampler.TH (
   ConstructorName (MkConstructorName),
   ListTypeDistributions (unListTypeDistributions),
@@ -66,7 +66,7 @@ findTypeSyn = \case
   Plain tn -> getSynonym tn <&> ConT . coerce
   List tn -> getSynonym tn <&> AppT ListT . ConT . coerce
 
-getDistribution :: TypeVariant -> SamplerGen (Distribution ())
+getDistribution :: TypeVariant -> SamplerGen Distribution
 getDistribution = \case
   Plain tn -> do
     distributions <- asks typeDistributions

test/Spec.hs

@@ -1,5 +1,5 @@
 import Test.Tasty (TestTree, defaultMain, testGroup)
-import qualified Test.Unit.Samplable as Samplable
+import qualified Test.Unit.Distribution as Distribution
 
 main :: IO ()
 main = defaultMain tests
@@ -9,4 +9,4 @@ tests = testGroup "Unit tests" unitTests
 
 unitTests :: [TestTree]
 unitTests =
-  [Samplable.unitTests]
+  [Distribution.unitTests]

test/Test/Unit/Distribution.hs

@@ -1,7 +1,7 @@
-module Test.Unit.Samplable (unitTests) where
+module Test.Unit.Distribution (unitTests) where
 
 import Control.Monad (replicateM)
-import Data.Boltzmann.Samplable (Distribution (..), choice)
+import Data.Boltzmann.Distribution (Distribution (..), choice)
 import Data.BuffonMachine (evalIO)
 import qualified Data.Map as Map
 import Data.Vector (fromList)
@@ -46,25 +46,25 @@ choiceTests =
     ]
 
 -- [1/2, 1/2]
-distributionA :: Distribution a
+distributionA :: Distribution
 distributionA = Distribution $ fromList [2, 3, -2, -1]
 
 -- [1/3, 1/3, 1/3]
-distributionB :: Distribution a
+distributionB :: Distribution
 distributionB = Distribution $ fromList [2, 138, 4, 137, 6, 133, 8, 132, 10, 128, 12, 127, 14, 123, 16, 122, 18, 118, 20, 117, 22, 113, 24, 112, 26, 108, 28, 107, 30, 103, 32, 102, 34, 98, 36, 97, 38, 93, 40, 92, 42, 88, 44, 87, 46, 83, 48, 82, 50, 78, 52, 77, 54, 73, 56, 72, 58, 68, 60, 67, 62, 66, 64, 65, -2, -1, -3, -3, 70, 71, -2, -1, -3, 75, 76, -2, -1, -3, 80, 81, -2, -1, -3, 85, 86, -2, -1, -3, 90, 91, -2, -1, -3, 95, 96, -2, -1, -3, 100, 101, -2, -1, -3, 105, 106, -2, -1, -3, 110, 111, -2, -1, -3, 115, 116, -2, -1, -3, 120, 121, -2, -1, -3, 125, 126, -2, -1, -3, 130, 131, -2, -1, -3, 135, 136, -2, -1, -3, 140, 141, -2, -1]
 
 -- [1/7, 4/7, 2/7]
-distributionC :: Distribution a
+distributionC :: Distribution
 distributionC = Distribution $ fromList [2, 96, 4, 95, 6, 94, 8, 93, 10, 92, 12, 91, 14, 90, 16, 89, 18, 88, 20, 87, 22, 86, 24, 85, 26, 84, 28, 83, 30, 82, 32, 81, 34, 80, 36, 79, 38, 78, 40, 77, 42, 76, 44, 75, 46, 74, 48, 73, 50, 72, 52, 71, 54, 70, 56, 69, 58, 68, 60, 67, 62, 66, 64, 65, -3, -1, -2, -1, -3, -2, -1, -3, -2, -1, -3, -2, -1, -3, -2, -1, -3, -2, -1, -3, -2, -1, -3, -2, -1, -3, -2, -1, -3, -2, -1, -3, -2]
 
-distributionD :: Distribution a
+distributionD :: Distribution
 distributionD = Distribution $ fromList []
 
-choiceTest :: Distribution a -> Int -> IO [(Int, Double)]
+choiceTest :: Distribution -> Int -> IO [(Int, Double)]
 choiceTest dist n = evalIO $ do
   sam <- replicateM n (choice @SMGen dist)
   let groups = frequency sam
-  return $ map (\(k, s) -> (k, fromIntegral s / fromIntegral n)) groups
+  pure $ map (\(k, s) -> (k, fromIntegral s / fromIntegral n)) groups
 
 frequency :: (Ord a) => [a] -> [(a, Int)]
 frequency xs = Map.toList (Map.fromListWith (+) [(x, 1) | x <- xs])