Created
September 17, 2014 11:19
-
-
Save tinkhaven/a31218239d7f2daebac1 to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import Test.QuickCheck | |
import Criterion.Main | |
{- | |
- Alternative using list comprehension | |
-} | |
allButLast :: (a -> a) -> [a] -> [a] | |
allButLast f [] = [] | |
allButLast f l = reverse $ last l : [f x | x <- tail (reverse l)] | |
allButLast2 :: (a -> a) -> [a] -> [a] | |
allButLast2 f [] = [] | |
allButLast2 f l = | |
let (x:xs) = reverse l | |
in reverse $ x : [f x | x <- xs] | |
{- | |
- creds: @Rvion | |
-} | |
mapInit :: (a -> a) -> [a] -> [a] | |
mapInit f l = map f (init l) ++ [last l] | |
{- | |
- creds: @bheklilr | |
-} | |
mapBut1 :: (a -> a) -> [a] -> [a] | |
mapBut1 f [] = [] | |
mapBut1 f [x] = [x] | |
mapBut1 f (x:xs) = f x : mapBut1 f xs | |
{- | |
- Creds: @Will Ness | |
-} | |
mapButLast :: (a -> a) -> [a] -> [a] | |
mapButLast f = para g [] | |
where | |
g x [] r = [x] | |
g x _ r = f x : r | |
para f z (x:xs) = f x xs (para f z xs) | |
para f z [] = z | |
prop_Id_AllButLast xs = allButLast (\x -> x - 1) (allButLast (+ 1) xs) == xs | |
where types = xs::[Int] | |
prop_Id_AllButLast2 xs = allButLast2 (\x -> x - 1) (allButLast2 (+ 1) xs) == xs | |
where types = xs::[Int] | |
prop_Id_MapInit xs = allButLast2 (\x -> x - 1) (allButLast2 (+ 1) xs) == xs | |
where types = xs::[Int] | |
prop_Id_MapBut1 xs = mapBut1 (\x -> x - 1) (mapBut1 (+ 1) xs) == xs | |
where types = xs::[Int] | |
prop_Id_Para xs = mapButLast (\x -> x - 1) (mapButLast (+ 1) xs) == xs | |
where types = xs::[Int] | |
-- Our benchmark harness. | |
main = defaultMain [ | |
bgroup "allbutlast" [ bench "1" $ nf ablplus $ (take 1 [1..] :: [Int]) | |
, bench "10" $ nf ablplus $ (take 10 [1..] :: [Int]) | |
, bench "100" $ nf ablplus $ (take 100 [1..] :: [Int]) | |
, bench "1000" $ nf ablplus $ (take 1000 [1..] :: [Int]) | |
-- , bench "1000000" $ whnf ablplus $ (take 1000000 [1..] :: [Int]) | |
] | |
, | |
bgroup "allbutlast2" [ bench "1" $ nf abl2plus $ (take 1 [1..] :: [Int]) | |
, bench "10" $ nf abl2plus $ (take 10 [1..] :: [Int]) | |
, bench "100" $ nf abl2plus $ (take 100 [1..] :: [Int]) | |
, bench "1000" $ nf abl2plus $ (take 1000 [1..] :: [Int]) | |
-- , bench "1000000" $ nf abl2plus $ (take 1000000 [1..] :: [Int]) | |
] | |
, | |
bgroup "mapInit" [ bench "1" $ nf mapInitplus $ (take 1 [1..] :: [Int]) | |
, bench "10" $ nf mapInitplus $ (take 10 [1..] :: [Int]) | |
, bench "100" $ nf mapInitplus $ (take 100 [1..] :: [Int]) | |
, bench "1000" $ nf mapInitplus $ (take 1000 [1..] :: [Int]) | |
-- , bench "1000000" $ nf mapInitplus $ (take 1000000 [1..] :: [Int]) | |
] | |
, | |
bgroup "mapBut1" [ bench "1" $ nf mapBut1plus $ (take 1 [1..] :: [Int]) | |
, bench "10" $ nf mapBut1plus $ (take 10 [1..] :: [Int]) | |
, bench "100" $ nf mapBut1plus $ (take 100 [1..] :: [Int]) | |
, bench "1000" $ nf mapBut1plus $ (take 1000 [1..] :: [Int]) | |
-- , bench "1000000" $ nf mapBut1plus $ (take 1000000 [1..] :: [Int]) | |
] | |
, | |
bgroup "para" [ bench "1" $ nf mapButLastplus $ (take 1 [1..] :: [Int]) | |
, bench "10" $ nf mapButLastplus $ (take 10 [1..] :: [Int]) | |
, bench "100" $ nf mapButLastplus $ (take 100 [1..] :: [Int]) | |
, bench "1000" $ nf mapButLastplus $ (take 1000 [1..] :: [Int]) | |
-- , bench "1000000" $ nf mapButLastplus $ (take 1000000 [1..] :: [Int]) | |
] | |
] | |
where | |
ablplus :: [Int] -> [Int] | |
ablplus = allButLast (+ 1) | |
abl2plus :: [Int] -> [Int] | |
abl2plus = allButLast2 (+ 1) | |
mapInitplus :: [Int] -> [Int] | |
mapInitplus = mapInit (+ 1) | |
mapBut1plus :: [Int] -> [Int] | |
mapBut1plus = mapBut1 (+ 1) | |
mapButLastplus :: [Int] -> [Int] | |
mapButLastplus = mapButLast (+ 1) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment