DList benchmarks

DList.hs

{-# OPTIONS_GHC -O2 #-}
import Control.Monad
import Control.Exception
import System.Time.Extra

import Criterion.Main

type DList a = [a] -> [a]

dTo f = f []
dSnoc f x = f . (x:)

data DType a = Nil | Snoc (DType a) a

tTo x = f x []
    where f Nil x = x
          f (Snoc xs x) acc = f xs (x:acc)
tSnoc f x = Snoc f x

build nil snoc i = f i
    where f 0 = nil
          f i = snoc (build nil snoc (i-1)) i 

count = 1000 :: Int

main = defaultMain [
  bgroup "dlist" [ bench "dlist"  $ nf (dTo . build id dSnoc) count
               , bench "snoc"  $ nf (tTo . build Nil tSnoc) count
               , bench "reverse"  $ nf (reverse . build [] (flip (:))) count
               ]
  ]