module Test.Data.Function where

import Data.Function as Func
import Test.QuickCheck (TestGroup(..), TestResult, quickCheck)
import Prelude hiding (flip, const, apply, identity, filter)

f :: Int->[Int]
f n = [n]

g :: [Int]->String
g x = show x

f2 :: Int->String->String
f2 n str = (show n) ++ str

compose :: Int->Bool
compose n = (Func.compose g f) n == (\x -> g (f x)) n

composeFlipped :: Int->Bool
composeFlipped n = ((Func.composeFlipped f g) n) == ((Func.compose g f) n)

flip :: Int->String->Bool
flip n str = ((Func.flip f2) str n) == f2 n str

const :: Int -> Int -> Bool
const a b = (Func.const a b) == a

apply :: Int->Bool
apply n = (Func.apply f n) == f n

pipeline :: Int->Bool
pipeline n = (Func.pipeline n f) == (f n)

identity :: Int->Bool
identity n = (Func.identity n == n)

test :: TestGroup (Integer -> IO TestResult)
test = Exe [
    quickCheck "compose" compose
  , quickCheck "composeFlipped" composeFlipped
  , quickCheck "flip" flip
  , quickCheck "const" const
  , quickCheck "apply" apply
  , quickCheck "pipeline" pipeline
  , quickCheck "identity" identity
]