generic-arbitrary-1.0.0: Generic implementation for QuickCheck's Arbitrary
Safe HaskellNone
LanguageHaskell2010

Test.QuickCheck.Arbitrary.Generic

Description

This module is a generic implementation of the arbitrary method. Example usage:

data Foo = Foo
  { _fooX :: X
  , _fooY :: Y
  } deriving (Generic)

instance Arbitrary Foo where
  arbitrary = genericArbitrary
  shrink = genericShrink

This instance can also be derived using DerivingVia language extension

data Foo = Foo
  { _fooX :: X
  , _fooY :: Y
  } deriving (Generic)
    deriving (Arbitrary) via GenericArbitrary Foo

The generated arbitrary method is equivalent to

Foo <$> arbitrary <*> arbitrary

.

It can also handle a recursive types problem. Assuming a type

data R = R R
  deriving Generic

there is no instance

instance Arbitrary R where
  arbitrary = genericArbitrary
  shrink = genericShrink

If you try to compile this you will get a type level error

   • R refers to itself in all constructors

Which means that there is no finite term for R because it is recursive. But, if you correct the definition of R like this.

data R = R R | F
  deriving Generic

Then it will compile. And the arbitrary generated will not hang forever, because it respects the size parameter.

There is a limitation of recursion detection:

data R1 = R1 R2
  deriving (Eq, Ord, Show, Generic)
  deriving anyclass NFData
  deriving Arbitrary via (GenericArbitrary R1)

data R2 = R2 R1
  deriving (Eq, Ord, Show, Generic)
  deriving anyclass NFData
  deriving Arbitrary via (GenericArbitrary R2)

This code will compile and the arbitrary generated will always hang. Yes, there is a problem with mutually recursive types.

Now lets see an example of datatype with parameters

data A a = A a
  deriving (Eq, Ord, Show)
  deriving anyclass NFData
  deriving (Generic)

instance (Arbitrary a) => Arbitrary (A a) where
  arbitrary = genericArbitrary
  shrink = genericShrink

It should work from first glance, but when compile it will throw an error:

    • Could not deduce (Test.QuickCheck.Arbitrary.Generic.GArbitrary
                          (A a)
                          (GHC.Generics.D1
                             ('GHC.Generics.MetaData A ParametersTest "main" 'False)
                             (GHC.Generics.C1
                                ('GHC.Generics.MetaCons A 'GHC.Generics.PrefixI 'False)
                                (GHC.Generics.S1
                                   ('GHC.Generics.MetaSel
                                      'Nothing
                                      'GHC.Generics.NoSourceUnpackedness
                                      'GHC.Generics.NoSourceStrictness
                                      'GHC.Generics.DecidedLazy)
                                   (GHC.Generics.Rec0 a))))
                          (TypesDiffer (A a) a))
        arising from a use of ‘genericArbitrary’

Here the TypesDiffer is a type familty dealing with recursive types and helping us to eliminate inproper instances. To convince the compiller, that the a parameter is not an A a we must fix the instance with additional constraint

instance (Arg (A a) a, Arbitrary a) => Arbitrary (A a) where
  arbitrary = genericArbitrary
  shrink = genericShrink

Now everything compiles and works as expected.

Synopsis

Main

genericArbitrary :: forall a ga some. (Generic a, GArbitrary a ga some, ga ~ Rep a) => Gen a Source #

newtype GenericArbitrary a Source #

Newtype for DerivingVia

Usage:

data Foo = Foo
  { _fooX :: X
  , _fooY :: Y
  } deriving (Generic)
    deriving (Arbitrary) via GenericArbitrary Foo

Since: 1.0.0

Constructors

GenericArbitrary 

Fields

type Arg self field = TypesDiffer self field ~ 'True Source #

Constraint helper for types with parameters

Usage:

data A a = A a
  deriving (Generic)
instance (Arg (A a) a, Arbitrary a) => Arbitrary (A a) where
  arbitrary = genericArbitrary
  shrink = genericShrink

Since: 1.0.0

Internal

class Finite self a ~ finite => GArbitrary self a (finite :: Bool) Source #

Generic arbitrary.

Parameters are: * self: the ADT we generating instance for * a: some part of the `Rep self` * finite: Is a finite? Infinite type has no finite values (like Stream)

Minimal complete definition

gArbitrary

Instances

Instances details
GArbitrary self (U1 :: Type -> Type) 'True Source #

Unit type instance

Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen (U1 x)

(GArbitrary self a af, GArbitrary self b bf, KnownNat (SumLen a), KnownNat (SumLen b), (af || bf) ~ some) => GArbitrary self (a :+: b) some Source #

Any sum inside of declaration

Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen ((a :+: b) x)

(GArbitrary self a af, GArbitrary self b bf, (af && bf) ~ some) => GArbitrary self (a :*: b) some Source #

Product

Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen ((a :*: b) x)

(Arbitrary t, Finite self (K1 R t :: Type -> Type) ~ some) => GArbitrary self (K1 R t :: Type -> Type) some Source #

Data of the constructor field

Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen (K1 R t x)

(TypeError ('ShowType self :<>: 'Text " refers to itself in all constructors") :: Constraint, (Finite self a || Finite self b) ~ 'False) => GArbitrary self (M1 D t (a :+: b)) 'False Source # 
Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen (M1 D t (a :+: b) x)

(FiniteSum self a b af bf, GArbitrary self (a :+: b) 'True) => GArbitrary self (M1 D t (a :+: b)) 'True Source #

ADT declaration with multiple constructors

Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen (M1 D t (a :+: b) x)

(TypeError ('ShowType self :<>: 'Text " refers to itself in all constructors") :: Constraint, AllFieldsFinal self f ~ 'False) => GArbitrary self (M1 D t (M1 C c f)) 'False Source # 
Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen (M1 D t (M1 C c f) x)

GArbitrary self f some => GArbitrary self (M1 S t f) some Source #

Constructor field meta information

Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen (M1 S t f x)

(GArbitrary self f some, KnownNat (ArgumentsCount f), AllFieldsFinal self f ~ some) => GArbitrary self (M1 C c f) some Source #

The constructor meta information

Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen (M1 C c f x)

GArbitrary self (M1 C c f) 'True => GArbitrary self (M1 D t (M1 C c f)) 'True Source # 
Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

gArbitrary :: Proxy self -> Gen (M1 D t (M1 C c f) x)

class (Finite self a ~ af, Finite self b ~ bf) => FiniteSum self (a :: * -> *) (b :: * -> *) af bf Source #

Minimal complete definition

finiteSum

Instances

Instances details
(FiniteSumElem self b, Finite self a ~ 'False, Finite self b ~ 'True) => FiniteSum self a b 'False 'True Source # 
Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

finiteSum :: Proxy self -> [Gen ((a :+: b) p)]

(FiniteSumElem self a, Finite self a ~ 'True, Finite self b ~ 'False) => FiniteSum self a b 'True 'False Source # 
Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

finiteSum :: Proxy self -> [Gen ((a :+: b) p)]

(FiniteSumElem self a, FiniteSumElem self b, Finite self a ~ 'True, Finite self b ~ 'True) => FiniteSum self a b 'True 'True Source # 
Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

finiteSum :: Proxy self -> [Gen ((a :+: b) p)]

class FiniteSumElem self a Source #

Minimal complete definition

finiteElem

Instances

Instances details
FiniteSum self a b af bf => FiniteSumElem (self :: Type) (a :+: b :: Type -> Type) Source # 
Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

finiteElem :: forall (p :: k). Proxy self -> [Gen ((a :+: b) p)]

GArbitrary self (M1 C c f) 'True => FiniteSumElem (self :: Type) (M1 C c f :: Type -> Type) Source # 
Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Methods

finiteElem :: forall (p :: k). Proxy self -> [Gen (M1 C c f p)]

type family Finite self (a :: * -> *) :: Bool where ... Source #

Equations

Finite self U1 = 'True 
Finite self (K1 R field) = TypesDiffer self field 
Finite self (a :*: b) = Finite self a && Finite self b 
Finite self (M1 D t f) = Finite self f 
Finite self (a :+: b) = Finite self a || Finite self b 
Finite self (M1 C c f) = AllFieldsFinal self f 
Finite self (M1 S s f) = Finite self f 

type family AllFieldsFinal self (a :: * -> *) :: Bool where ... Source #

Equations

AllFieldsFinal self U1 = 'True 
AllFieldsFinal self (a :*: b) = AllFieldsFinal self a && AllFieldsFinal self b 
AllFieldsFinal self (M1 S t (K1 R field)) = TypesDiffer self field 

type family TypesDiffer a b where ... Source #

Equations

TypesDiffer a a = 'False 
TypesDiffer a b = 'True 

type family ArgumentsCount (a :: * -> *) :: Nat where ... Source #

type family SumLen a :: Nat where ... Source #

Calculates count of constructors encoded by particular :+:. Internal use only.

Equations

SumLen (a :+: b) = SumLen a + SumLen b 
SumLen a = 1 

Reexports

class Arbitrary a where #

Random generation and shrinking of values.

QuickCheck provides Arbitrary instances for most types in base, except those which incur extra dependencies. For a wider range of Arbitrary instances see the quickcheck-instances package.

Minimal complete definition

arbitrary

Methods

arbitrary :: Gen a #

A generator for values of the given type.

It is worth spending time thinking about what sort of test data you want - good generators are often the difference between finding bugs and not finding them. You can use sample, label and classify to check the quality of your test data.

There is no generic arbitrary implementation included because we don't know how to make a high-quality one. If you want one, consider using the testing-feat or generic-random packages.

The QuickCheck manual goes into detail on how to write good generators. Make sure to look at it, especially if your type is recursive!

shrink :: a -> [a] #

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

The default implementation returns the empty list, so will not try to shrink the value. If your data type has no special invariants, you can enable shrinking by defining shrink = genericShrink, but by customising the behaviour of shrink you can often get simpler counterexamples.

Most implementations of shrink should try at least three things:

  1. Shrink a term to any of its immediate subterms. You can use subterms to do this.
  2. Recursively apply shrink to all immediate subterms. You can use recursivelyShrink to do this.
  3. Type-specific shrinkings such as replacing a constructor by a simpler constructor.

For example, suppose we have the following implementation of binary trees:

data Tree a = Nil | Branch a (Tree a) (Tree a)

We can then define shrink as follows:

shrink Nil = []
shrink (Branch x l r) =
  -- shrink Branch to Nil
  [Nil] ++
  -- shrink to subterms
  [l, r] ++
  -- recursively shrink subterms
  [Branch x' l' r' | (x', l', r') <- shrink (x, l, r)]

There are a couple of subtleties here:

  • QuickCheck tries the shrinking candidates in the order they appear in the list, so we put more aggressive shrinking steps (such as replacing the whole tree by Nil) before smaller ones (such as recursively shrinking the subtrees).
  • It is tempting to write the last line as [Branch x' l' r' | x' <- shrink x, l' <- shrink l, r' <- shrink r] but this is the wrong thing! It will force QuickCheck to shrink x, l and r in tandem, and shrinking will stop once one of the three is fully shrunk.

There is a fair bit of boilerplate in the code above. We can avoid it with the help of some generic functions. The function genericShrink tries shrinking a term to all of its subterms and, failing that, recursively shrinks the subterms. Using it, we can define shrink as:

shrink x = shrinkToNil x ++ genericShrink x
  where
    shrinkToNil Nil = []
    shrinkToNil (Branch _ l r) = [Nil]

genericShrink is a combination of subterms, which shrinks a term to any of its subterms, and recursivelyShrink, which shrinks all subterms of a term. These may be useful if you need a bit more control over shrinking than genericShrink gives you.

A final gotcha: we cannot define shrink as simply shrink x = Nil:genericShrink x as this shrinks Nil to Nil, and shrinking will go into an infinite loop.

If all this leaves you bewildered, you might try shrink = genericShrink to begin with, after deriving Generic for your type. However, if your data type has any special invariants, you will need to check that genericShrink can't break those invariants.

Instances

Instances details
Arbitrary Bool 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Bool #

shrink :: Bool -> [Bool] #

Arbitrary Char 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Char #

shrink :: Char -> [Char] #

Arbitrary Double 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary Float 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Float #

shrink :: Float -> [Float] #

Arbitrary Int 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Int #

shrink :: Int -> [Int] #

Arbitrary Int8 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Int8 #

shrink :: Int8 -> [Int8] #

Arbitrary Int16 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Int16 #

shrink :: Int16 -> [Int16] #

Arbitrary Int32 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Int32 #

shrink :: Int32 -> [Int32] #

Arbitrary Int64 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Int64 #

shrink :: Int64 -> [Int64] #

Arbitrary Integer 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary Ordering 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary Word 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Word #

shrink :: Word -> [Word] #

Arbitrary Word8 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Word8 #

shrink :: Word8 -> [Word8] #

Arbitrary Word16 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary Word32 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary Word64 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary () 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen () #

shrink :: () -> [()] #

Arbitrary Version

Generates Version with non-empty non-negative versionBranch, and empty versionTags

Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary QCGen 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen QCGen #

shrink :: QCGen -> [QCGen] #

Arbitrary ASCIIString 
Instance details

Defined in Test.QuickCheck.Modifiers

Arbitrary UnicodeString 
Instance details

Defined in Test.QuickCheck.Modifiers

Arbitrary PrintableString 
Instance details

Defined in Test.QuickCheck.Modifiers

Arbitrary ExitCode 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary All 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen All #

shrink :: All -> [All] #

Arbitrary Any 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen Any #

shrink :: Any -> [Any] #

Arbitrary CChar 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen CChar #

shrink :: CChar -> [CChar] #

Arbitrary CSChar 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CUChar 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CShort 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CUShort 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CInt 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen CInt #

shrink :: CInt -> [CInt] #

Arbitrary CUInt 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen CUInt #

shrink :: CUInt -> [CUInt] #

Arbitrary CLong 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen CLong #

shrink :: CLong -> [CLong] #

Arbitrary CULong 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CLLong 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CULLong 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CFloat 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CDouble 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CPtrdiff 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CSize 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen CSize #

shrink :: CSize -> [CSize] #

Arbitrary CWchar 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CSigAtomic 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CClock 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CTime 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen CTime #

shrink :: CTime -> [CTime] #

Arbitrary CUSeconds 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CSUSeconds 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CIntPtr 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CUIntPtr 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CIntMax 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary CUIntMax 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary IntSet 
Instance details

Defined in Test.QuickCheck.Arbitrary

Arbitrary a => Arbitrary [a] 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen [a] #

shrink :: [a] -> [[a]] #

Arbitrary a => Arbitrary (Maybe a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Maybe a) #

shrink :: Maybe a -> [Maybe a] #

Integral a => Arbitrary (Ratio a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Ratio a) #

shrink :: Ratio a -> [Ratio a] #

Arbitrary a => Arbitrary (Blind a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Blind a) #

shrink :: Blind a -> [Blind a] #

Arbitrary a => Arbitrary (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Fixed a) #

shrink :: Fixed a -> [Fixed a] #

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

Defined in Test.QuickCheck.Modifiers

Arbitrary a => Arbitrary (NonEmptyList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Arbitrary a => Arbitrary (InfiniteList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

(Arbitrary a, Ord a) => Arbitrary (SortedList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

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

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Positive a) #

shrink :: Positive a -> [Positive a] #

(Num a, Ord a, Arbitrary a) => Arbitrary (Negative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Negative a) #

shrink :: Negative a -> [Negative a] #

(Num a, Eq a, Arbitrary a) => Arbitrary (NonZero a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (NonZero a) #

shrink :: NonZero a -> [NonZero a] #

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

Defined in Test.QuickCheck.Modifiers

(Num a, Ord a, Arbitrary a) => Arbitrary (NonPositive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

(Integral a, Bounded a) => Arbitrary (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Large a) #

shrink :: Large a -> [Large a] #

Integral a => Arbitrary (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Small a) #

shrink :: Small a -> [Small a] #

Arbitrary a => Arbitrary (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Shrink2 a) #

shrink :: Shrink2 a -> [Shrink2 a] #

Arbitrary a => Arbitrary (Smart a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Smart a) #

shrink :: Smart a -> [Smart a] #

Arbitrary a => Arbitrary (Complex a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Complex a) #

shrink :: Complex a -> [Complex a] #

Arbitrary a => Arbitrary (ZipList a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (ZipList a) #

shrink :: ZipList a -> [ZipList a] #

Arbitrary a => Arbitrary (Identity a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Identity a) #

shrink :: Identity a -> [Identity a] #

Arbitrary a => Arbitrary (First a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (First a) #

shrink :: First a -> [First a] #

Arbitrary a => Arbitrary (Last a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Last a) #

shrink :: Last a -> [Last a] #

Arbitrary a => Arbitrary (Dual a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Dual a) #

shrink :: Dual a -> [Dual a] #

(Arbitrary a, CoArbitrary a) => Arbitrary (Endo a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Endo a) #

shrink :: Endo a -> [Endo a] #

Arbitrary a => Arbitrary (Sum a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Sum a) #

shrink :: Sum a -> [Sum a] #

Arbitrary a => Arbitrary (Product a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Product a) #

shrink :: Product a -> [Product a] #

Arbitrary a => Arbitrary (IntMap a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (IntMap a) #

shrink :: IntMap a -> [IntMap a] #

Arbitrary a => Arbitrary (Tree a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Tree a) #

shrink :: Tree a -> [Tree a] #

Arbitrary a => Arbitrary (Seq a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Seq a) #

shrink :: Seq a -> [Seq a] #

(Ord a, Arbitrary a) => Arbitrary (Set a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Set a) #

shrink :: Set a -> [Set a] #

(Generic a, GArbitrary a (Rep a) some, RecursivelyShrink (Rep a), GSubterms (Rep a) a) => Arbitrary (GenericArbitrary a) Source # 
Instance details

Defined in Test.QuickCheck.Arbitrary.Generic

Arbitrary a => Arbitrary (InfiniteListInternalData a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (InfiniteListInternalData a) #

shrink :: InfiniteListInternalData a -> [InfiniteListInternalData a] #

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

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a -> b) #

shrink :: (a -> b) -> [a -> b] #

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

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Either a b) #

shrink :: Either a b -> [Either a b] #

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

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a, b) #

shrink :: (a, b) -> [(a, b)] #

(Function a, CoArbitrary a, Arbitrary b) => Arbitrary (a :-> b) 
Instance details

Defined in Test.QuickCheck.Function

Methods

arbitrary :: Gen (a :-> b) #

shrink :: (a :-> b) -> [a :-> b] #

(Function a, CoArbitrary a, Arbitrary b) => Arbitrary (Fun a b) 
Instance details

Defined in Test.QuickCheck.Function

Methods

arbitrary :: Gen (Fun a b) #

shrink :: Fun a b -> [Fun a b] #

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

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Shrinking s a) #

shrink :: Shrinking s a -> [Shrinking s a] #

HasResolution a => Arbitrary (Fixed a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Fixed a) #

shrink :: Fixed a -> [Fixed a] #

Arbitrary (m a) => Arbitrary (WrappedMonad m a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (WrappedMonad m a) #

shrink :: WrappedMonad m a -> [WrappedMonad m a] #

(Ord k, Arbitrary k, Arbitrary v) => Arbitrary (Map k v) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Map k v) #

shrink :: Map k v -> [Map k v] #

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

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a, b, c) #

shrink :: (a, b, c) -> [(a, b, c)] #

Arbitrary (a b c) => Arbitrary (WrappedArrow a b c) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (WrappedArrow a b c) #

shrink :: WrappedArrow a b c -> [WrappedArrow a b c] #

Arbitrary a => Arbitrary (Const a b) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Const a b) #

shrink :: Const a b -> [Const a b] #

Arbitrary (f a) => Arbitrary (Alt f a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Alt f a) #

shrink :: Alt f a -> [Alt f a] #

Arbitrary a => Arbitrary (Constant a b) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Constant a b) #

shrink :: Constant a b -> [Constant a b] #

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

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a, b, c, d) #

shrink :: (a, b, c, d) -> [(a, b, c, d)] #

(Arbitrary1 f, Arbitrary1 g, Arbitrary a) => Arbitrary (Product f g a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Product f g a) #

shrink :: Product f g a -> [Product f g a] #

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

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a, b, c, d, e) #

shrink :: (a, b, c, d, e) -> [(a, b, c, d, e)] #

(Arbitrary1 f, Arbitrary1 g, Arbitrary a) => Arbitrary (Compose f g a) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (Compose f g a) #

shrink :: Compose f g a -> [Compose f g a] #

(Arbitrary a, Arbitrary b, Arbitrary c, Arbitrary d, Arbitrary e, Arbitrary f) => Arbitrary (a, b, c, d, e, f) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a, b, c, d, e, f) #

shrink :: (a, b, c, d, e, f) -> [(a, b, c, d, e, f)] #

(Arbitrary a, Arbitrary b, Arbitrary c, Arbitrary d, Arbitrary e, Arbitrary f, Arbitrary g) => Arbitrary (a, b, c, d, e, f, g) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a, b, c, d, e, f, g) #

shrink :: (a, b, c, d, e, f, g) -> [(a, b, c, d, e, f, g)] #

(Arbitrary a, Arbitrary b, Arbitrary c, Arbitrary d, Arbitrary e, Arbitrary f, Arbitrary g, Arbitrary h) => Arbitrary (a, b, c, d, e, f, g, h) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a, b, c, d, e, f, g, h) #

shrink :: (a, b, c, d, e, f, g, h) -> [(a, b, c, d, e, f, g, h)] #

(Arbitrary a, Arbitrary b, Arbitrary c, Arbitrary d, Arbitrary e, Arbitrary f, Arbitrary g, Arbitrary h, Arbitrary i) => Arbitrary (a, b, c, d, e, f, g, h, i) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a, b, c, d, e, f, g, h, i) #

shrink :: (a, b, c, d, e, f, g, h, i) -> [(a, b, c, d, e, f, g, h, i)] #

(Arbitrary a, Arbitrary b, Arbitrary c, Arbitrary d, Arbitrary e, Arbitrary f, Arbitrary g, Arbitrary h, Arbitrary i, Arbitrary j) => Arbitrary (a, b, c, d, e, f, g, h, i, j) 
Instance details

Defined in Test.QuickCheck.Arbitrary

Methods

arbitrary :: Gen (a, b, c, d, e, f, g, h, i, j) #

shrink :: (a, b, c, d, e, f, g, h, i, j) -> [(a, b, c, d, e, f, g, h, i, j)] #

genericShrink :: (Generic a, RecursivelyShrink (Rep a), GSubterms (Rep a) a) => a -> [a] #

Shrink a term to any of its immediate subterms, and also recursively shrink all subterms.