{-# OPTIONS_GHC -O2 -fexcess-precision -Wall #-}
{-
ghc -o dist/build/generator-speed -package=synthesizer-core speedtest/Generator.hs

These options achieve only little speedup of the slowest implementation sum0:
 -fvia-C -optc-ffast-math -optc-O3
-}
module Main where

import qualified Synthesizer.State.Signal as SigS
import Control.Monad.Trans.State (runStateT, )


signal :: SigS.T Double
signal =
   SigS.take (100*1000*1000) $
   SigS.iterate (1+) 0

sum0 :: Double
sum0 =
   let recurse acc =
          SigS.switchL acc (\x -> recurse (acc+x))
   in  recurse 0 signal

sum1 :: Double
sum1 =
   case signal of
     SigS.Cons nextAction s ->
       let next = runStateT nextAction
           recurse acc =
              maybe acc (\(x,sn) -> recurse (acc+x) sn) . next
       in  recurse 0 s

sum2 :: Double
sum2 =
   SigS.runViewL signal
     (\next s ->
       let recurse acc =
              maybe acc (\(x,sn) -> recurse (acc+x) sn) . next
       in  recurse 0 s)

sum3 :: Double
sum3 =
   SigS.runSwitchL signal
     (\next s ->
       let recurse acc =
              next acc (\x sn -> recurse (acc+x) sn)
       in  recurse 0 s)

sum4 :: Double
sum4 =
   SigS.foldL (+) 0 signal

main :: IO ()
main = print sum4