1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
{-# LANGUAGE TypeFamilies #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Main (main) where
import Control.Applicative hiding (Const)
import Data.Reify
import System.CPUTime
import Prelude
data List a b = Nil | Cons a b
deriving Show
instance MuRef [a] where
type DeRef [a] = List a
mapDeRef f (x:xs) = Cons x <$> f xs
mapDeRef _ [] = pure Nil
instance Functor (List a) where
fmap _ Nil = Nil
fmap f (Cons a b) = Cons a (f b)
main :: IO ()
main = do
let g1 :: [Int]
g1 = [1..10]
reifyGraph g1 >>= print
let g2 :: [Int]
g2 = [1..10] ++ g2
reifyGraph g2 >>= print
-- now, some timings.
ns <- sequence [ timeme n | n <- take 8 (iterate (*2) 1024) ]
print $ reverse $ take 4 $ reverse [ n2 / n1 | (n1,n2) <- zip ns (tail ns) ]
timeme :: Int -> IO Float
timeme n = do
i <- getCPUTime
let g3 = [1..n] ++ g3
reifyGraph g3 >>= \ (Graph xs _) -> putStr $ show (length xs)
j <- getCPUTime
let n' :: Float
n' = fromIntegral ((j - i) `div` 1000000000)
putStrLn $ " ==> " ++ show (n' / 1000)
return n'
|
