*Main> quickCheck prop_sorted
*** Failed! Falsified (after 6 tests and 4 shrinks):
[0,-1]

*Main> quickCheck prop_quick_sort 
+++ OK, passed 100 tests.

*Main> prop1 [3, 5, 1,2 ]
False

*Main> quickCheck prop_quick_sort
*** Failed! Exception: 'Prelude.tail: empty list' (after 1 test):
[]
*Main> prop1 []
*** Exception: Prelude.tail: empty list

*Main> quickCheck prop_quick_sort
+++ OK, passed 100 tests; 16 discarded.
*Main> :t arbitrary
arbitrary :: Arbitrary a => Gen a
*Main> :t generate 
generate :: Gen a -> IO a
*Main> generate (arbitrary :: Gen Integer)
-26
*Main> generate (arbitrary :: Gen String)
"\r"
*Main> generate (arbitrary :: Gen String)
"'1Mo\SYN\170244\1064495Q\DC3"
*Main> :t choose 
choose :: random-1.1:System.Random.Random a => (a, a) -> Gen a
*Main> generate (choose (1, 2) :: Gen Int) 
1
*Main> generate (choose (1, 2) :: Gen Int) 
1
*Main> generate (choose (1, 2) :: Gen Int) 
1
*Main> generate (choose (1, 2) :: Gen Int) 
2
*Main> generate (choose (1, -2) :: Gen Int) 
0
*Main> generate (choose (1, -2) :: Gen Int) 
-1
*Main> generate (choose (1, -2) :: Gen Int) 
-1
*Main> generate (choose (1, -2) :: Gen Int) 
-1
*Main> generate (choose (1, -2) :: Gen Int) 
-2
*Main> generate (choose (1, 1) :: Gen Int) 
1
*Main> generate (choose (1, 1) :: Gen Int) 
1
*Main> generate (choose (1, 1) :: Gen Int) 
1
*Main> :t elements
elements :: [a] -> Gen a
*Main> generate $ elements ['a','e','i','o','u'] 
'u'
*Main> generate $ elements ['a','e','i','o','u'] 
'u'
*Main> generate $ elements ['a','e','i','o','u'] 
'a'
*Main> generate $ elements ['a','e','i','o','u'] 
'e'

*Main> :t vector
vector :: Arbitrary a => Int -> Gen [a]
*Main> generate $ (vector 100 :: Gen [Int]) 
[-4,26,20,-21,17,9,-8,-12,-8,8,-26,-22,6,8,-12,16,4,25,25,-7,6,2,30,-2,20,-17,-8,-18,-4,-27,-16,-10,-5,0,-8,-14,29,16,2,20,-23,6,3,-20,21,-27,-17,-4,-29,-22,20,11,-8,-16,-27,29,-2,-25,15,-26,-4,27,-23,-15,1,-25,-18,9,-11,-21,-10,13,26,-16,19,-23,-29,-25,25,7,-7,-12,21,-22,26,4,11,4,13,-20,-23,21,-29,-2,5,-17,-9,-16,3,-23]
*Main> generate $ (vector 7 :: Gen [Int]) 
[-17,24,14,-22,10,-29,-25]

*Main> :t frequency
frequency :: [(Int, Gen a)] -> Gen a
*Main> generate $ frequency [(1, elements ['e', 'f', 'g']), (1, elements ['a', 'b', 'c']), (1, vector 10 :: Gen [Char ])]

<interactive>:82:89: error:
    • Couldn't match type ‘[Char]’ with ‘Char’
      Expected type: Gen Char
        Actual type: Gen [Char]
    • In the expression: vector 10 :: Gen [Char]
      In the expression: (1, vector 10 :: Gen [Char])
      In the first argument of ‘frequency’, namely
        ‘[(1, elements ['e', 'f', ....]), (1, elements ['a', 'b', ....]),
          (1, vector 10 :: Gen [Char])]’

*Main> generate $ frequency [(1, elements ["e", "f", "g"]), (1, elements ["a", "b", "c"]), (1, vector 10 :: Gen [Char ])]
"g"
*Main> generate $ frequency [(1, elements ["e", "f", "g"]), (1, elements ["a", "b", "c"]), (1, vector 10 :: Gen [Char ])]
"\11604Nt\GS[\66673\DC4\US\\\55147"
*Main> generate $ frequency [(1, elements ["e", "f", "g"]), (1, elements ["a", "b", "c"]), (1, vector 10 :: Gen [Char ])]
"(]\ESCp\1096670\1045825\EM\STXy|"
*Main> generate $ frequency [(1, elements ["e", "f", "g"]), (1, elements ["a", "b", "c"]), (1, vector 10 :: Gen [Char ])]
"g"
*Main> generate $ frequency [(1, elements ["e", "f", "g"]), (1, elements ["a", "b", "c"]), (1, vector 10 :: Gen [Char ])]
"g"
*Main> generate $ frequency [(1, elements ["e", "f", "g"]), (1, elements ["a", "b", "c"]), (1, vector 10 :: Gen [Char ])]
"f"
*Main> generate $ frequency [(1, elements ["e", "f", "g"]), (1, elements ["a", "b", "c"]), (1, vector 10 :: Gen [Char ])]
"a"

*Main> generate (arbitrary :: Gen Color)
Red
*Main> generate (arbitrary :: Gen Color)
Blue
*Main> :t forAll 
forAll
  :: (Show a, Testable prop) => Gen a -> (a -> prop) -> Property

*Main> quickCheck prop_replicate'' 
*** Failed! Exception: 'Prelude.!!: index too large' (after 1 test):
0
0
0