Test.QuickCheck.Arbitrary

Arbitrary and CoArbitrary classes.

class Arbitrary a where

Random generation and shrinking of values.

Methods

arbitrary :: Gen a

A generator for values of the given type.

shrink :: a -> [a]

Produces a (possibly) empty list of all the possible immediate shrinks of the given value.

Instances

Arbitrary Bool

Arbitrary Char

Arbitrary Double

Arbitrary Float

Arbitrary Int

Arbitrary Integer

Arbitrary ()

Arbitrary OrdC

Arbitrary OrdB

Arbitrary OrdA

Arbitrary C

Arbitrary B

Arbitrary A

Arbitrary a => Arbitrary [a]

(Integral a, Arbitrary a) => Arbitrary (Ratio a)

Arbitrary a => Arbitrary (Maybe a)

(RealFloat a, Arbitrary a) => Arbitrary (Complex a)

Arbitrary a => Arbitrary (Smart a)

Arbitrary a => Arbitrary (Shrink2 a)

(Num a, Ord a, Arbitrary a) => Arbitrary (NonNegative a)

(Num a, Ord a, Arbitrary a) => Arbitrary (NonZero a)

(Num a, Ord a, Arbitrary a) => Arbitrary (Positive a)

Arbitrary a => Arbitrary (NonEmptyList a)

(Ord a, Arbitrary a) => Arbitrary (OrderedList a)

Arbitrary a => Arbitrary (Fixed a)

Arbitrary a => Arbitrary (Blind a)

(CoArbitrary a, Arbitrary b) => Arbitrary (a -> b)

(Arbitrary a, Arbitrary b) => Arbitrary (Either a b)

(Arbitrary a, Arbitrary b) => Arbitrary (a, b)

(Arbitrary a, ShrinkState s a) => Arbitrary (Shrinking s a)

(FunArbitrary a, Arbitrary b) => Arbitrary (Fun a b)

(FunArbitrary a, Arbitrary c) => Arbitrary (:-> a c)

(Arbitrary a, Arbitrary b, Arbitrary c) => Arbitrary (a, b, c)

(Arbitrary a, Arbitrary b, Arbitrary c, Arbitrary d) => Arbitrary (a, b, c, d)

(Arbitrary a, Arbitrary b, Arbitrary c, Arbitrary d, Arbitrary e) => Arbitrary (a, b, c, d, e)

class CoArbitrary a where

Used for random generation of functions.

Methods

coarbitrary :: a -> Gen c -> Gen c

Used to generate a function of type a -> c. The implementation should use the first argument to perturb the random generator given as the second argument. the returned generator is then used to generate the function result. You can often use variant and >< to implement coarbitrary.

Instances

CoArbitrary Bool

CoArbitrary Char

CoArbitrary Double

CoArbitrary Float

CoArbitrary Int

CoArbitrary Integer

CoArbitrary ()

CoArbitrary OrdC

CoArbitrary OrdB

CoArbitrary OrdA

CoArbitrary C

CoArbitrary B

CoArbitrary A

CoArbitrary a => CoArbitrary [a]

(Integral a, CoArbitrary a) => CoArbitrary (Ratio a)

CoArbitrary a => CoArbitrary (Maybe a)

(RealFloat a, CoArbitrary a) => CoArbitrary (Complex a)

(Arbitrary a, CoArbitrary b) => CoArbitrary (a -> b)

(CoArbitrary a, CoArbitrary b) => CoArbitrary (Either a b)

(CoArbitrary a, CoArbitrary b) => CoArbitrary (a, b)

(CoArbitrary a, CoArbitrary b, CoArbitrary c) => CoArbitrary (a, b, c)

(CoArbitrary a, CoArbitrary b, CoArbitrary c, CoArbitrary d) => CoArbitrary (a, b, c, d)

(CoArbitrary a, CoArbitrary b, CoArbitrary c, CoArbitrary d, CoArbitrary e) => CoArbitrary (a, b, c, d, e)

Helper functions for implementing arbitrary

arbitrarySizedIntegral :: Num a => Gen a

Generates an integral number. The number can be positive or negative and its maximum absolute value depends on the size parameter.

arbitrarySizedFractional :: Fractional a => Gen a

Generates a fractional number. The number can be positive or negative and its maximum absolute value depends on the size parameter.

arbitraryBoundedIntegral :: (Bounded a, Integral a) => Gen a

Generates an integral number. The number is chosen from the entire range of the type.

arbitraryBoundedRandom :: (Bounded a, Random a) => Gen a

Generates an element of a bounded type. The element is chosen from the entire range of the type.

Helper functions for implementing shrink

shrinkNothing :: a -> [a]

Returns no shrinking alternatives.

shrinkList :: (a -> [a]) -> [a] -> [[a]]

shrinkIntegral :: Integral a => a -> [a]

Shrink an integral number.

shrinkRealFrac :: RealFrac a => a -> [a]

Shrink a fraction.

Helper functions for implementing coarbitrary

(><) :: (Gen a -> Gen a) -> (Gen a -> Gen a) -> Gen a -> Gen a

Combine two generator perturbing functions, for example the results of calls to variant or coarbitrary.

coarbitraryIntegral :: Integral a => a -> Gen b -> Gen b

A coarbitrary implementation for integral numbers.

coarbitraryReal :: Real a => a -> Gen b -> Gen b

A coarbitrary implementation for real numbers.

coarbitraryShow :: Show a => a -> Gen b -> Gen b

coarbitrary helper for lazy people :-).

Generators which use arbitrary

vector :: Arbitrary a => Int -> Gen [a]

Generates a list of a given length.

orderedList :: (Ord a, Arbitrary a) => Gen [a]

Generates an ordered list of a given length.