{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
module Main ( main ) where

import Control.Eff
import Control.Eff.State.Strict
import Control.Applicative
import Control.DeepSeq
import Control.Exception ( evaluate )
import Control.Monad

import Criterion
import Criterion.Config
import Criterion.Main

import System.Random.Effect

fastIntDist :: Member (State Random) r
            => Int
            -> Int
            -> Eff r Int
fastIntDist a' b' = do
  let a = min a' b'
      b = max a' b'
      range = b - a

  x <- randomInt
  return (x `rem` range + a)
{-# NOINLINE fastIntDist #-}

instance NFData a => Benchmarkable (Eff (State Random :> ()) a) where
  run eff n = do
    let res = Control.Eff.run $ runRandomState (mkRandom 0) $ do
                last <$> replicateM n eff

    _ <- evaluate (rnf res)
    return ()

main :: IO ()
main =
  defaultMainWith config (return ()) [
      bcompare [
        bench "fastIntDist"    (fastIntDist    1 1000 :: Eff (State Random :> ()) Int)
      , bench "uniformIntDist" (uniformIntDist 1 1000 :: Eff (State Random :> ()) Integer)
      ]
    ]
  where
    config = defaultConfig {
    --  cfgPerformGC = ljust True
     cfgConfInterval = ljust 0.99
    }