-- |
-- Module : Benchmarks.StreamlyPure
-- Copyright : (c) 2018 Harendra Kumar
--
-- License : MIT
-- Maintainer : harendra.kumar@gmail.com
{-# LANGUAGE CPP #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE ScopedTypeVariables #-}
module Benchmarks.StreamlyPure where
import Benchmarks.Common (value, maxValue, appendValue)
import Data.Functor.Identity (Identity, runIdentity)
import Prelude
(Int, (+), ($), (.), even, (>), (<=),
subtract, undefined, Maybe(..), foldMap, maxBound)
import qualified Prelude as P
import qualified Streamly.Prelude as S
-------------------------------------------------------------------------------
-- Stream generation
-------------------------------------------------------------------------------
type Stream = S.SerialT Identity
{-# INLINE source #-}
source :: Int -> Stream Int
source n = S.unfoldr step n
where
step cnt =
if cnt > n + value
then Nothing
else (Just (cnt, cnt + 1))
{-# INLINE sourceN #-}
sourceN :: Int -> Int -> Stream Int
sourceN count begin = S.unfoldr step begin
where
step i =
if i > begin + count
then Nothing
else (Just (i, i + 1))
-------------------------------------------------------------------------------
-- Append
-------------------------------------------------------------------------------
{-# INLINE appendSourceR #-}
appendSourceR :: Int -> Stream Int
appendSourceR n = foldMap S.fromPure [n..n+appendValue]
{-# INLINE appendSourceL #-}
appendSourceL :: Int -> Stream Int
appendSourceL n = P.foldl (P.<>) S.nil (P.map S.fromPure [n..n+appendValue])
-------------------------------------------------------------------------------
-- Elimination
-------------------------------------------------------------------------------
-- Using NFData for evaluation may be fraught with problems because of a
-- non-optimal implementation of NFData instance. So we just evaluate each
-- element of the stream using a fold.
{-# INLINE eval #-}
eval :: Stream a -> ()
eval = runIdentity . S.foldrM P.seq (P.return ())
-- eval foldable
{-# INLINE evalF #-}
evalF :: P.Foldable t => t a -> ()
evalF = P.foldr P.seq ()
{-# INLINE toNull #-}
toNull :: Stream Int -> ()
toNull = eval
{-# INLINE toList #-}
toList :: Stream Int -> ()
toList = evalF . runIdentity . S.toList
{-# INLINE foldl #-}
foldl :: Stream Int -> Int
foldl = runIdentity . S.foldl' (+) 0
{-# INLINE last #-}
last :: Stream Int -> Maybe Int
last = runIdentity . S.last
-------------------------------------------------------------------------------
-- Transformation
-------------------------------------------------------------------------------
{-# INLINE transform #-}
transform :: Stream a -> ()
transform = eval
{-# INLINE composeN #-}
composeN :: Int -> (Stream Int -> Stream Int) -> Stream Int -> ()
composeN n f =
case n of
1 -> transform . f
2 -> transform . f . f
3 -> transform . f . f . f
4 -> transform . f . f . f . f
_ -> undefined
{-# INLINE scan #-}
{-# INLINE map #-}
{-# INLINE mapM #-}
{-# INLINE filterEven #-}
{-# INLINE filterAllOut #-}
{-# INLINE filterAllIn #-}
{-# INLINE takeOne #-}
{-# INLINE takeAll #-}
{-# INLINE takeWhileTrue #-}
{-# INLINE dropOne #-}
{-# INLINE dropAll #-}
{-# INLINE dropWhileTrue #-}
{-# INLINE dropWhileFalse #-}
scan, map, mapM,
filterEven, filterAllOut, filterAllIn,
takeOne, takeAll, takeWhileTrue,
dropOne, dropAll, dropWhileTrue, dropWhileFalse
:: Int -> Stream Int -> ()
scan n = composeN n $ S.scanl' (+) 0
map n = composeN n $ S.map (+1)
mapM = map
filterEven n = composeN n $ S.filter even
filterAllOut n = composeN n $ S.filter (> maxValue)
filterAllIn n = composeN n $ S.filter (<= maxValue)
takeOne n = composeN n $ S.take 1
takeAll n = composeN n $ S.take maxValue
takeWhileTrue n = composeN n $ S.takeWhile (<= maxValue)
dropOne n = composeN n $ S.drop 1
dropAll n = composeN n $ S.drop maxValue
dropWhileFalse n = composeN n $ S.dropWhile (> maxValue)
dropWhileTrue n = composeN n $ S.dropWhile (<= maxValue)
-------------------------------------------------------------------------------
-- Iteration
-------------------------------------------------------------------------------
iterStreamLen, maxIters :: Int
iterStreamLen = 10
maxIters = 100000
{-# INLINE iterateSource #-}
iterateSource :: (Stream Int -> Stream Int) -> Int -> Int -> Stream Int
iterateSource g i n = f i (sourceN iterStreamLen n)
where
f (0 :: Int) m = g m
f x m = g (f (x P.- 1) m)
{-# INLINE iterateScan #-}
{-# INLINE iterateFilterEven #-}
{-# INLINE iterateTakeAll #-}
{-# INLINE iterateDropOne #-}
{-# INLINE iterateDropWhileFalse #-}
{-# INLINE iterateDropWhileTrue #-}
iterateScan, iterateFilterEven, iterateTakeAll, iterateDropOne,
iterateDropWhileFalse, iterateDropWhileTrue :: Int -> Stream Int
-- this is quadratic
iterateScan n = iterateSource (S.scanl' (+) 0) (maxIters `P.div` 100) n
iterateDropWhileFalse n =
iterateSource (S.dropWhile (> maxValue)) (maxIters `P.div` 100) n
iterateFilterEven n = iterateSource (S.filter even) maxIters n
iterateTakeAll n = iterateSource (S.take maxValue) maxIters n
iterateDropOne n = iterateSource (S.drop 1) maxIters n
iterateDropWhileTrue n = iterateSource (S.dropWhile (<= maxValue)) maxIters n
-------------------------------------------------------------------------------
-- Mixed Composition
-------------------------------------------------------------------------------
{-# INLINE scanMap #-}
{-# INLINE dropMap #-}
{-# INLINE dropScan #-}
{-# INLINE takeDrop #-}
{-# INLINE takeScan #-}
{-# INLINE takeMap #-}
{-# INLINE filterDrop #-}
{-# INLINE filterTake #-}
{-# INLINE filterScan #-}
{-# INLINE filterMap #-}
scanMap, dropMap, dropScan, takeDrop, takeScan, takeMap, filterDrop,
filterTake, filterScan, filterMap
:: Int -> Stream Int -> ()
scanMap n = composeN n $ S.map (subtract 1) . S.scanl' (+) 0
dropMap n = composeN n $ S.map (subtract 1) . S.drop 1
dropScan n = composeN n $ S.scanl' (+) 0 . S.drop 1
takeDrop n = composeN n $ S.drop 1 . S.take maxValue
takeScan n = composeN n $ S.scanl' (+) 0 . S.take maxValue
takeMap n = composeN n $ S.map (subtract 1) . S.take maxValue
filterDrop n = composeN n $ S.drop 1 . S.filter (<= maxValue)
filterTake n = composeN n $ S.take maxValue . S.filter (<= maxValue)
filterScan n = composeN n $ S.scanl' (+) 0 . S.filter (<= maxBound)
filterMap n = composeN n $ S.map (subtract 1) . S.filter (<= maxValue)
-------------------------------------------------------------------------------
-- Zipping and concat
-------------------------------------------------------------------------------
-- {-# INLINE zip #-}
-- zip :: Stream Int -> ()
-- zip src = runIdentity $ S.foldr (\(x,y) xs -> P.seq x (P.seq y xs)) ()
-- $ S.zipWith (,) src src
{-# INLINE concatMap #-}
concatMap :: Stream Int -> ()
concatMap src = transform $ (S.concatMap (S.replicate 3) src)