ModuleQuickCheck-2.15.0.1Haskell2010

Test.QuickCheck.Function

Generation of random shrinkable, showable functions. See the paper "Shrinking and showing functions" by Koen Claessen.

Note: most of the contents of this module are re-exported by Test.QuickCheck. You probably do not need to import it directly.

Example of use:

Example5 expressions

>>> :{>>> let prop :: Fun String Integer -> Bool>>>     prop (Fun _ f) = f "monkey" == f "banana" || f "banana" == f "elephant">>> :}>>> quickCheck prop*** Failed! Falsified (after 3 tests and 134 shrinks):{"elephant"->1, "monkey"->1, _->0}

To generate random values of type Fun a b, you must have an instance Function a. If your type has a Show instance, you can use functionShow to write the instance; otherwise, use functionMap to give a bijection between your type and a type that is already an instance of Function. See the Function [a] instance for an example of the latter.

2 types
1 class
14 values

PackageQuickCheck-2.15.0.1
Exports20
LanguageHaskell2010
LicenceBSD-3-Clause
SourceFunction.hs

datadata Fun a b

Generation of random shrinkable, showable functions.

To generate random values of type Fun a b, you must have an instance Function a.

See also applyFun, and Fn with GHC >= 7.8.

Constructors

Fun (a :-> b, b, Shrunk) (a -> b)

Instances3Functor, Show, Arbitrary

Functor (Fun a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Show a, Show b) => Show (Fun a b)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Function a, CoArbitrary a, Arbitrary b) => Arbitrary (Fun a b)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function

valueapplyFun :: Fun a b -> a -> b

Extracts the value of a function.

Fn is the pattern equivalent of this function.

prop :: Fun String Integer -> Bool
prop f = applyFun f "banana" == applyFun f "monkey"
      || applyFun f "banana" == applyFun f "elephant"

valueapply :: Fun a b -> a -> b

Alias to applyFun.

valueapplyFun2 :: Fun (a, b) c -> a -> b -> c

Extracts the value of a binary function.

Fn2 is the pattern equivalent of this function.

prop_zipWith :: Fun (Int, Bool) Char -> [Int] -> [Bool] -> Bool
prop_zipWith f xs ys = zipWith (applyFun2 f) xs ys == [ applyFun2 f x y | (x, y) <- zip xs ys]

valueapplyFun3 :: Fun (a, b, c) d -> a -> b -> c -> d

Extracts the value of a ternary function. Fn3 is the pattern equivalent of this function.

datadata (:->) a c where

The type of possibly partial concrete functions

Instances3Functor, Show, Arbitrary

Functor ((:->) a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Show a, Show b) => Show (a :-> b)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Function a, CoArbitrary a, Arbitrary b) => Arbitrary (a :-> b)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function

classclass Function a where

The class Function a is used for random generation of showable functions of type a -> b.

There is a default implementation for function, which you can use if your type has structural equality. Otherwise, you can normally use functionMap or functionShow.

Methods

function :: (a -> b) -> a :-> b

Instances53Function, …

Function ADefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function BDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function CDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function OrdADefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function OrdBDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function OrdCDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function IntSetDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function IntegerDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function AllDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function AnyDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function NewlineDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function NewlineModeDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function Int16Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function Int32Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function Int64Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function Int8Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function Word16Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function Word32Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function Word64Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function Word8Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function BoolDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function CharDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function DoubleDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function FloatDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function IntDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function OrderingDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function WordDefined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function ()Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (IntMap a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (Seq a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (Tree a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (Identity a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (First a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (Last a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (Dual a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (Product a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (Sum a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (Maybe a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function [a]Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(RealFloat a, Function a) => Function (Complex a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Integral a, Function a) => Function (Ratio a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Ord a, Function a) => Function (Set a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
HasResolution a => Function (Fixed a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Function a, Function b) => Function (Either a b)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Function a, Function b) => Function (a, b)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Ord a, Function a, Function b) => Function (Map a b)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function (f a) => Function (Alt f a)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
Function a => Function (Const a b)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Function a, Function b, Function c) => Function (a, b, c)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Function a, Function b, Function c, Function d) => Function (a, b, c, d)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Function a, Function b, Function c, Function d, Function e) => Function (a, b, c, d, e)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Function a, Function b, Function c, Function d, Function e, Function f) => Function (a, b, c, d, e, f)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function
(Function a, Function b, Function c, Function d, Function e, Function f, Function g) => Function (a, b, c, d, e, f, g)Defined in QuickCheck-2.15.0.1 · Test.QuickCheck.Function

valuefunctionMap :: Function b => (a -> b) -> (b -> a) -> (a -> c) -> a :-> c

The basic building block for Function instances. Provides a Function instance by mapping to and from a type that already has a Function instance.

valuefunctionShow :: (Show a, Read a) => (a -> c) -> a :-> c

Provides a Function instance for types with Show and Read.

valuefunctionIntegral :: Integral a => (a -> b) -> a :-> b

Provides a Function instance for types with Integral.

valuefunctionRealFrac :: RealFrac a => (a -> b) -> a :-> b

Provides a Function instance for types with RealFrac.

valuefunctionBoundedEnum :: (Eq a, Bounded a, Enum a) => (a -> b) -> a :-> b

Provides a Function instance for types with Bounded and Enum. Use only for small types (i.e. not integers): creates the list [minBound..maxBound]!

valuefunctionElements :: Eq a => [a] -> (a -> b) -> a :-> b

Provides a Function instance for small finite types.

valuefunctionVoid :: (forall b. void -> b) -> void :-> c

Provides a Function instance for types isomorphic to Void.

An actual Function Void instance is defined in quickcheck-instances.

valuefunctionMapWith

:: (b -> c) -> b :-> c
-> a -> b
-> b -> a
-> a -> c
-> a :-> c

valuefunctionEitherWith

:: (a -> c) -> a :-> c
-> (b -> c) -> b :-> c
-> Either a b -> c
-> Either a b :-> c

valuefunctionPairWith

:: (a -> b -> c) -> a :-> (b -> c)
-> (b -> c) -> b :-> c
-> (a, b) -> c
-> (a, b) :-> c

patternpattern Fn :: (a -> b) -> Fun a b

A modifier for testing functions.

prop :: Fun String Integer -> Bool
prop (Fn f) = f "banana" == f "monkey"
           || f "banana" == f "elephant"

patternpattern Fn2 :: (a -> b -> c) -> Fun (a, b) c

A modifier for testing binary functions.

prop_zipWith :: Fun (Int, Bool) Char -> [Int] -> [Bool] -> Bool
prop_zipWith (Fn2 f) xs ys = zipWith f xs ys == [ f x y | (x, y) <- zip xs ys]

patternpattern Fn3 :: (a -> b -> c -> d) -> Fun (a, b, c) d

A modifier for testing ternary functions.