polysemy/bench/countDown.hs

{-# LANGUAGE DataKinds, DeriveFunctor, FlexibleContexts, GADTs, TypeOperators #-}
module Main (main) where

import Control.Monad (replicateM_)

import qualified Control.Monad.Except as MTL
import qualified Control.Monad.State as MTL
import qualified Control.Monad.Free as Free

import Criterion (bench, bgroup, whnf)
import Criterion.Main (defaultMain)

import Control.Monad.Freer (Member, Eff, run, send)
import Control.Monad.Freer.Internal (Eff(..), decomp, qApp, tsingleton)
import Control.Monad.Freer.Error (runError, throwError)
import Control.Monad.Freer.State (get, put, runState)

import qualified Poly as P

--------------------------------------------------------------------------------
                        -- State Benchmarks --
--------------------------------------------------------------------------------

oneGet :: Int -> (Int, Int)
oneGet n = run (runState n get)

oneGetMTL :: Int -> (Int, Int)
oneGetMTL = MTL.runState MTL.get

countDown :: Int -> (Int, Int)
countDown start = run (runState start go)
  where go = get >>= (\n -> if n <= 0 then pure n else put (n-1) >> go)

countDownMTL :: Int -> (Int, Int)
countDownMTL = MTL.runState go
  where go = MTL.get >>= (\n -> if n <= 0 then pure n else MTL.put (n-1) >> go)

--------------------------------------------------------------------------------
                       -- Exception + State --
--------------------------------------------------------------------------------
countDownExc :: Int -> Either String (Int,Int)
countDownExc start = run $ runError (runState start go)
  where go = get >>= (\n -> if n <= (0 :: Int) then throwError "wat" else put (n-1) >> go)

countDownExcMTL :: Int -> Either String (Int,Int)
countDownExcMTL = MTL.runStateT go
  where go = MTL.get >>= (\n -> if n <= (0 :: Int) then MTL.throwError "wat" else MTL.put (n-1) >> go)

--------------------------------------------------------------------------------
                          -- Freer: Interpreter --
--------------------------------------------------------------------------------
data Http out where
  Open :: String -> Http ()
  Close :: Http ()
  Post  :: String -> Http String
  Get   :: Http String

open' :: Member Http r => String -> Eff r ()
open'  = send . Open

close' :: Member Http r => Eff r ()
close' = send Close

post' :: Member Http r => String -> Eff r String
post' = send . Post

get' :: Member Http r => Eff r String
get' = send Get

runHttp :: Eff (Http ': r) w -> Eff r w
runHttp (Val x) = pure x
runHttp (E u q) = case decomp u of
  Right (Open _) -> runHttp (qApp q ())
  Right Close    -> runHttp (qApp q ())
  Right (Post d) -> runHttp (qApp q d)
  Right Get      -> runHttp (qApp q "")
  Left u'        -> E u' (tsingleton (runHttp . qApp q ))

--------------------------------------------------------------------------------
                          -- Free: Interpreter --
--------------------------------------------------------------------------------
data FHttpT x
  = FOpen String x
  | FClose x
  | FPost String (String -> x)
  | FGet (String -> x)
    deriving Functor

type FHttp = Free.Free FHttpT

fopen' :: String -> FHttp ()
fopen' s = Free.liftF $ FOpen s ()

fclose' :: FHttp ()
fclose' = Free.liftF $ FClose ()

fpost' :: String -> FHttp String
fpost' s = Free.liftF $ FPost s id

fget' :: FHttp String
fget' = Free.liftF $ FGet id

runFHttp :: FHttp a -> Maybe a
runFHttp (Free.Pure x) = pure x
runFHttp (Free.Free (FOpen _ n)) = runFHttp n
runFHttp (Free.Free (FClose n))  = runFHttp n
runFHttp (Free.Free (FPost s n)) = pure s  >>= runFHttp . n
runFHttp (Free.Free (FGet n))    = pure "" >>= runFHttp . n

--------------------------------------------------------------------------------
                        -- Benchmark Suite --
--------------------------------------------------------------------------------
prog :: Member Http r => Eff r ()
prog = open' "cats" >> get' >> post' "cats" >> close'

prog' :: FHttp ()
prog' = fopen' "cats" >> fget' >> fpost' "cats" >> fclose'

p :: Member Http r => Int -> Eff r ()
p count   =  open' "cats" >> replicateM_ count (get' >> post' "cats") >>  close'

p' :: Int -> FHttp ()
p' count  = fopen' "cats" >> replicateM_ count (fget' >> fpost' "cats") >> fclose'

main :: IO ()
main =
  defaultMain [
    bgroup "Countdown Bench" [
        bench "discount"          $ whnf P.countDown 10000
      , bench "freer-simple"      $ whnf countDown 10000
      , bench "mtl"               $ whnf countDownMTL 10000
    ]
  ]