itemsEqual.hs

import Data.List
import qualified Data.Set as Set
import Criterion.Main

itemsEqualOnDiff :: (Eq a) => [a] -> [a] -> Bool
itemsEqualOnDiff [] [] = True
itemsEqualOnDiff [] _ = False
itemsEqualOnDiff _ [] = False
itemsEqualOnDiff (aHead:aTail) b = itemsEqualOnDiff aTail $ delete aHead b

itemsEqualOnSort :: (Eq a, Ord a) => [a] -> [a] -> Bool
itemsEqualOnSort a b = sort a == sort b

-- Note: produces incorrect results for lists with duplicate items
itemsEqualOnSet :: (Eq a, Ord a) => [a] -> [a] -> Bool
itemsEqualOnSet a b = Set.fromList a == Set.fromList b

shuf1 :: [Int]
shuf1 = [84,91,16,32,29,19,77,89,38,86,17,9,94,81,21,35,22,53,66,98,28,40,1,23,97,74,80,67,30,82,76,27,79,90,54,20,58,87,75,42,73,61,60,6,7,96,10,69,5,8,50,85,11,37,43,68,56,62,78,12,83,51,46,41,63,14,65,64,72,100,2,33,26,13,57,88,18,49,39,34,47,25,70,3,95,93,59,15,44,48,99,92,71,45,55,31,4,24,36,52]

shuf2 :: [Int]
shuf2 = [53,36,29,80,35,4,81,88,72,59,15,48,94,50,24,5,62,90,85,87,43,18,21,75,96,91,65,52,39,6,23,74,89,44,69,3,79,60,67,10,1,45,51,41,68,55,7,28,33,34,13,37,63,31,66,46,93,98,8,84,58,99,16,11,77,71,25,64,42,27,95,30,32,73,49,100,57,9,14,54,19,92,40,17,82,83,97,12,38,61,26,78,70,56,47,76,22,2,86,20]

main =
  defaultMain [
    bgroup "[1,1,4,2,3,5] [3,4,1,5,2,1]" [
      bench "itemsEqualOnDiff"
        $ nf (itemsEqualOnDiff [1,1,4,2,3,5]) [3,4,1,5,2,1],
      bench "itemsEqualOnSort"
        $ nf (itemsEqualOnSort [1,1,4,2,3,5]) [3,4,1,5,2,1],
      bench "itemsEqualOnSet"
        $ nf (itemsEqualOnSet [1,1,4,2,3,5]) [3,4,1,5,2,1]
    ],
    bgroup "(shuffle [0..100]) (shuffle [0..100])" [
      bench "itemsEqualOnDiff"
        $ nf (itemsEqualOnDiff shuf1) shuf2,
      bench "itemsEqualOnSort"
        $ nf (itemsEqualOnSort shuf1) shuf2,
      bench "itemsEqualOnSet"
        $ nf (itemsEqualOnSet shuf1) shuf2
    ]
  ]