{-# LANGUAGE TemplateHaskell #-}

-- Testing the ADT laws for sets:
module TestSets where

import Test.QuickCheck
--import Sets
--import SetsAsLists
import SetsAsOrdLists
import qualified Data.List (foldr)

type Elem = Int

prop_empty_list :: Elem -> Bool
prop_empty_list x = isElem x empty == False
                    
prop_elem_insert :: Elem -> Set Elem -> Bool
prop_elem_insert x s = isElem x (insert x s) == True

prop_insert_insert :: Elem -> Elem -> Set Elem -> Bool
prop_insert_insert x y s = isElem x (insert y (insert x s)) == True

prop_union :: Elem -> Set Elem -> Set Elem -> Bool
prop_union x s1 s2 = isElem x (union s1 s2) == isElem x s1 || isElem x s2

instance (Eq a, Ord a, Arbitrary a) => Arbitrary (Set a) where
  arbitrary = do s <- arbitrary -- generate an arbitrary list of `a` elements
                 return ((foldr :: (a->b->b) -> b -> [a] -> b) insert empty s)

-- run all property tests:
return []
testAll = $quickCheckAll