massiv-test-0.1.3: Library that contains generators, properties and tests for Massiv Array Library.

Safe HaskellNone
LanguageHaskell2010

Test.Massiv.Utils

Synopsis

Documentation

showsType :: forall t. Typeable t => ShowS Source #

Use Typeable to show the type.

showsArrayType :: forall r ix e. (Typeable r, Typeable ix, Typeable e) => ShowS Source #

Use Typeable to show the array type

assertException Source #

Arguments

:: (Testable b, NFData a, Exception exc) 
=> (exc -> b)

Return True if that is the exception that was expected

-> a

Value that should throw an exception, when fully evaluated

-> Property 

assertExceptionIO Source #

Arguments

:: (Testable b, NFData a, Exception exc) 
=> (exc -> b)

Return True if that is the exception that was expected

-> IO a

IO Action that should throw an exception

-> Property 

applyFun2Compat :: Fun (a, b) c -> a -> b -> c Source #

guard :: Alternative f => Bool -> f () #

Conditional failure of Alternative computations. Defined by

guard True  = pure ()
guard False = empty

Examples

Expand

Common uses of guard include conditionally signaling an error in an error monad and conditionally rejecting the current choice in an Alternative-based parser.

As an example of signaling an error in the error monad Maybe, consider a safe division function safeDiv x y that returns Nothing when the denominator y is zero and Just (x `div` y) otherwise. For example:

>>> safeDiv 4 0
Nothing
>>> safeDiv 4 2
Just 2

A definition of safeDiv using guards, but not guard:

safeDiv :: Int -> Int -> Maybe Int
safeDiv x y | y /= 0    = Just (x `div` y)
            | otherwise = Nothing

A definition of safeDiv using guard and Monad do-notation:

safeDiv :: Int -> Int -> Maybe Int
safeDiv x y = do
  guard (y /= 0)
  return (x `div` y)

join :: Monad m => m (m a) -> m a #

The join function is the conventional monad join operator. It is used to remove one level of monadic structure, projecting its bound argument into the outer level.

Examples

Expand

A common use of join is to run an IO computation returned from an STM transaction, since STM transactions can't perform IO directly. Recall that

atomically :: STM a -> IO a

is used to run STM transactions atomically. So, by specializing the types of atomically and join to

atomically :: STM (IO b) -> IO (IO b)
join       :: IO (IO b)  -> IO b

we can compose them as

join . atomically :: STM (IO b) -> IO b

to run an STM transaction and the IO action it returns.

class Applicative m => Monad (m :: Type -> Type) where #

The Monad class defines the basic operations over a monad, a concept from a branch of mathematics known as category theory. From the perspective of a Haskell programmer, however, it is best to think of a monad as an abstract datatype of actions. Haskell's do expressions provide a convenient syntax for writing monadic expressions.

Instances of Monad should satisfy the following laws:

Furthermore, the Monad and Applicative operations should relate as follows:

The above laws imply:

and that pure and (<*>) satisfy the applicative functor laws.

The instances of Monad for lists, Maybe and IO defined in the Prelude satisfy these laws.

Minimal complete definition

(>>=)

Methods

(>>=) :: m a -> (a -> m b) -> m b infixl 1 #

Sequentially compose two actions, passing any value produced by the first as an argument to the second.

(>>) :: m a -> m b -> m b infixl 1 #

Sequentially compose two actions, discarding any value produced by the first, like sequencing operators (such as the semicolon) in imperative languages.

return :: a -> m a #

Inject a value into the monadic type.

fail :: String -> m a #

Fail with a message. This operation is not part of the mathematical definition of a monad, but is invoked on pattern-match failure in a do expression.

As part of the MonadFail proposal (MFP), this function is moved to its own class MonadFail (see Control.Monad.Fail for more details). The definition here will be removed in a future release.

Instances
Monad []

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

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

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

return :: a -> [a] #

fail :: String -> [a] #

Monad Maybe

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

(>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b #

(>>) :: Maybe a -> Maybe b -> Maybe b #

return :: a -> Maybe a #

fail :: String -> Maybe a #

Monad IO

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

(>>=) :: IO a -> (a -> IO b) -> IO b #

(>>) :: IO a -> IO b -> IO b #

return :: a -> IO a #

fail :: String -> IO a #

Monad Par1

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(>>=) :: Par1 a -> (a -> Par1 b) -> Par1 b #

(>>) :: Par1 a -> Par1 b -> Par1 b #

return :: a -> Par1 a #

fail :: String -> Par1 a #

Monad Q 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

(>>=) :: Q a -> (a -> Q b) -> Q b #

(>>) :: Q a -> Q b -> Q b #

return :: a -> Q a #

fail :: String -> Q a #

Monad Rose 
Instance details

Defined in Test.QuickCheck.Property

Methods

(>>=) :: Rose a -> (a -> Rose b) -> Rose b #

(>>) :: Rose a -> Rose b -> Rose b #

return :: a -> Rose a #

fail :: String -> Rose a #

Monad Gen 
Instance details

Defined in Test.QuickCheck.Gen

Methods

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

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

return :: a -> Gen a #

fail :: String -> Gen a #

Monad Complex

Since: base-4.9.0.0

Instance details

Defined in Data.Complex

Methods

(>>=) :: Complex a -> (a -> Complex b) -> Complex b #

(>>) :: Complex a -> Complex b -> Complex b #

return :: a -> Complex a #

fail :: String -> Complex a #

Monad Min

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(>>=) :: Min a -> (a -> Min b) -> Min b #

(>>) :: Min a -> Min b -> Min b #

return :: a -> Min a #

fail :: String -> Min a #

Monad Max

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(>>=) :: Max a -> (a -> Max b) -> Max b #

(>>) :: Max a -> Max b -> Max b #

return :: a -> Max a #

fail :: String -> Max a #

Monad First

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(>>=) :: First a -> (a -> First b) -> First b #

(>>) :: First a -> First b -> First b #

return :: a -> First a #

fail :: String -> First a #

Monad Last

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(>>=) :: Last a -> (a -> Last b) -> Last b #

(>>) :: Last a -> Last b -> Last b #

return :: a -> Last a #

fail :: String -> Last a #

Monad Option

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(>>=) :: Option a -> (a -> Option b) -> Option b #

(>>) :: Option a -> Option b -> Option b #

return :: a -> Option a #

fail :: String -> Option a #

Monad Identity

Since: base-4.8.0.0

Instance details

Defined in Data.Functor.Identity

Methods

(>>=) :: Identity a -> (a -> Identity b) -> Identity b #

(>>) :: Identity a -> Identity b -> Identity b #

return :: a -> Identity a #

fail :: String -> Identity a #

Monad STM

Since: base-4.3.0.0

Instance details

Defined in GHC.Conc.Sync

Methods

(>>=) :: STM a -> (a -> STM b) -> STM b #

(>>) :: STM a -> STM b -> STM b #

return :: a -> STM a #

fail :: String -> STM a #

Monad First

Since: base-4.8.0.0

Instance details

Defined in Data.Monoid

Methods

(>>=) :: First a -> (a -> First b) -> First b #

(>>) :: First a -> First b -> First b #

return :: a -> First a #

fail :: String -> First a #

Monad Last

Since: base-4.8.0.0

Instance details

Defined in Data.Monoid

Methods

(>>=) :: Last a -> (a -> Last b) -> Last b #

(>>) :: Last a -> Last b -> Last b #

return :: a -> Last a #

fail :: String -> Last a #

Monad Dual

Since: base-4.8.0.0

Instance details

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Dual a -> (a -> Dual b) -> Dual b #

(>>) :: Dual a -> Dual b -> Dual b #

return :: a -> Dual a #

fail :: String -> Dual a #

Monad Sum

Since: base-4.8.0.0

Instance details

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Sum a -> (a -> Sum b) -> Sum b #

(>>) :: Sum a -> Sum b -> Sum b #

return :: a -> Sum a #

fail :: String -> Sum a #

Monad Product

Since: base-4.8.0.0

Instance details

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Product a -> (a -> Product b) -> Product b #

(>>) :: Product a -> Product b -> Product b #

return :: a -> Product a #

fail :: String -> Product a #

Monad Down

Since: base-4.11.0.0

Instance details

Defined in Data.Ord

Methods

(>>=) :: Down a -> (a -> Down b) -> Down b #

(>>) :: Down a -> Down b -> Down b #

return :: a -> Down a #

fail :: String -> Down a #

Monad ReadP

Since: base-2.1

Instance details

Defined in Text.ParserCombinators.ReadP

Methods

(>>=) :: ReadP a -> (a -> ReadP b) -> ReadP b #

(>>) :: ReadP a -> ReadP b -> ReadP b #

return :: a -> ReadP a #

fail :: String -> ReadP a #

Monad NonEmpty

Since: base-4.9.0.0

Instance details

Defined in GHC.Base

Methods

(>>=) :: NonEmpty a -> (a -> NonEmpty b) -> NonEmpty b #

(>>) :: NonEmpty a -> NonEmpty b -> NonEmpty b #

return :: a -> NonEmpty a #

fail :: String -> NonEmpty a #

Monad Tree 
Instance details

Defined in Data.Tree

Methods

(>>=) :: Tree a -> (a -> Tree b) -> Tree b #

(>>) :: Tree a -> Tree b -> Tree b #

return :: a -> Tree a #

fail :: String -> Tree a #

Monad Seq 
Instance details

Defined in Data.Sequence.Internal

Methods

(>>=) :: Seq a -> (a -> Seq b) -> Seq b #

(>>) :: Seq a -> Seq b -> Seq b #

return :: a -> Seq a #

fail :: String -> Seq a #

Monad Vector 
Instance details

Defined in Data.Vector

Methods

(>>=) :: Vector a -> (a -> Vector b) -> Vector b #

(>>) :: Vector a -> Vector b -> Vector b #

return :: a -> Vector a #

fail :: String -> Vector a #

Monad Box 
Instance details

Defined in Data.Vector.Fusion.Util

Methods

(>>=) :: Box a -> (a -> Box b) -> Box b #

(>>) :: Box a -> Box b -> Box b #

return :: a -> Box a #

fail :: String -> Box a #

Monad Id 
Instance details

Defined in Data.Vector.Fusion.Util

Methods

(>>=) :: Id a -> (a -> Id b) -> Id b #

(>>) :: Id a -> Id b -> Id b #

return :: a -> Id a #

fail :: String -> Id a #

Monad SmallArray 
Instance details

Defined in Data.Primitive.SmallArray

Methods

(>>=) :: SmallArray a -> (a -> SmallArray b) -> SmallArray b #

(>>) :: SmallArray a -> SmallArray b -> SmallArray b #

return :: a -> SmallArray a #

fail :: String -> SmallArray a #

Monad Array 
Instance details

Defined in Data.Primitive.Array

Methods

(>>=) :: Array a -> (a -> Array b) -> Array b #

(>>) :: Array a -> Array b -> Array b #

return :: a -> Array a #

fail :: String -> Array a #

Monad P

Since: base-2.1

Instance details

Defined in Text.ParserCombinators.ReadP

Methods

(>>=) :: P a -> (a -> P b) -> P b #

(>>) :: P a -> P b -> P b #

return :: a -> P a #

fail :: String -> P a #

Monad (Either e)

Since: base-4.4.0.0

Instance details

Defined in Data.Either

Methods

(>>=) :: Either e a -> (a -> Either e b) -> Either e b #

(>>) :: Either e a -> Either e b -> Either e b #

return :: a -> Either e a #

fail :: String -> Either e a #

Monad (U1 :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(>>=) :: U1 a -> (a -> U1 b) -> U1 b #

(>>) :: U1 a -> U1 b -> U1 b #

return :: a -> U1 a #

fail :: String -> U1 a #

Monoid a => Monad ((,) a)

Since: base-4.9.0.0

Instance details

Defined in GHC.Base

Methods

(>>=) :: (a, a0) -> (a0 -> (a, b)) -> (a, b) #

(>>) :: (a, a0) -> (a, b) -> (a, b) #

return :: a0 -> (a, a0) #

fail :: String -> (a, a0) #

Monad (ST s)

Since: base-2.1

Instance details

Defined in GHC.ST

Methods

(>>=) :: ST s a -> (a -> ST s b) -> ST s b #

(>>) :: ST s a -> ST s b -> ST s b #

return :: a -> ST s a #

fail :: String -> ST s a #

Monad m => Monad (PropertyM m) 
Instance details

Defined in Test.QuickCheck.Monadic

Methods

(>>=) :: PropertyM m a -> (a -> PropertyM m b) -> PropertyM m b #

(>>) :: PropertyM m a -> PropertyM m b -> PropertyM m b #

return :: a -> PropertyM m a #

fail :: String -> PropertyM m a #

Monad m => Monad (WrappedMonad m)

Since: base-4.7.0.0

Instance details

Defined in Control.Applicative

Methods

(>>=) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b #

(>>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b #

return :: a -> WrappedMonad m a #

fail :: String -> WrappedMonad m a #

ArrowApply a => Monad (ArrowMonad a)

Since: base-2.1

Instance details

Defined in Control.Arrow

Methods

(>>=) :: ArrowMonad a a0 -> (a0 -> ArrowMonad a b) -> ArrowMonad a b #

(>>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b #

return :: a0 -> ArrowMonad a a0 #

fail :: String -> ArrowMonad a a0 #

Monad (Proxy :: Type -> Type)

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

(>>=) :: Proxy a -> (a -> Proxy b) -> Proxy b #

(>>) :: Proxy a -> Proxy b -> Proxy b #

return :: a -> Proxy a #

fail :: String -> Proxy a #

Monad m => Monad (MaybeT m) 
Instance details

Defined in Control.Monad.Trans.Maybe

Methods

(>>=) :: MaybeT m a -> (a -> MaybeT m b) -> MaybeT m b #

(>>) :: MaybeT m a -> MaybeT m b -> MaybeT m b #

return :: a -> MaybeT m a #

fail :: String -> MaybeT m a #

Monad (SpecM a) 
Instance details

Defined in Test.Hspec.Core.Spec.Monad

Methods

(>>=) :: SpecM a a0 -> (a0 -> SpecM a b) -> SpecM a b #

(>>) :: SpecM a a0 -> SpecM a b -> SpecM a b #

return :: a0 -> SpecM a a0 #

fail :: String -> SpecM a a0 #

Monad m => Monad (ListT m) 
Instance details

Defined in Control.Monad.Trans.List

Methods

(>>=) :: ListT m a -> (a -> ListT m b) -> ListT m b #

(>>) :: ListT m a -> ListT m b -> ListT m b #

return :: a -> ListT m a #

fail :: String -> ListT m a #

Monad f => Monad (Rec1 f)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(>>=) :: Rec1 f a -> (a -> Rec1 f b) -> Rec1 f b #

(>>) :: Rec1 f a -> Rec1 f b -> Rec1 f b #

return :: a -> Rec1 f a #

fail :: String -> Rec1 f a #

Monad f => Monad (Ap f)

Since: base-4.12.0.0

Instance details

Defined in Data.Monoid

Methods

(>>=) :: Ap f a -> (a -> Ap f b) -> Ap f b #

(>>) :: Ap f a -> Ap f b -> Ap f b #

return :: a -> Ap f a #

fail :: String -> Ap f a #

Monad f => Monad (Alt f)

Since: base-4.8.0.0

Instance details

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Alt f a -> (a -> Alt f b) -> Alt f b #

(>>) :: Alt f a -> Alt f b -> Alt f b #

return :: a -> Alt f a #

fail :: String -> Alt f a #

(Applicative f, Monad f) => Monad (WhenMissing f x)

Equivalent to ReaderT k (ReaderT x (MaybeT f)).

Since: containers-0.5.9

Instance details

Defined in Data.IntMap.Internal

Methods

(>>=) :: WhenMissing f x a -> (a -> WhenMissing f x b) -> WhenMissing f x b #

(>>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b #

return :: a -> WhenMissing f x a #

fail :: String -> WhenMissing f x a #

Monad m => Monad (ExceptT e m) 
Instance details

Defined in Control.Monad.Trans.Except

Methods

(>>=) :: ExceptT e m a -> (a -> ExceptT e m b) -> ExceptT e m b #

(>>) :: ExceptT e m a -> ExceptT e m b -> ExceptT e m b #

return :: a -> ExceptT e m a #

fail :: String -> ExceptT e m a #

Monad (Array DS Ix1) 
Instance details

Defined in Data.Massiv.Array.Delayed.Stream

Methods

(>>=) :: Array DS Ix1 a -> (a -> Array DS Ix1 b) -> Array DS Ix1 b #

(>>) :: Array DS Ix1 a -> Array DS Ix1 b -> Array DS Ix1 b #

return :: a -> Array DS Ix1 a #

fail :: String -> Array DS Ix1 a #

Monad m => Monad (IdentityT m) 
Instance details

Defined in Control.Monad.Trans.Identity

Methods

(>>=) :: IdentityT m a -> (a -> IdentityT m b) -> IdentityT m b #

(>>) :: IdentityT m a -> IdentityT m b -> IdentityT m b #

return :: a -> IdentityT m a #

fail :: String -> IdentityT m a #

(Monad m, Error e) => Monad (ErrorT e m) 
Instance details

Defined in Control.Monad.Trans.Error

Methods

(>>=) :: ErrorT e m a -> (a -> ErrorT e m b) -> ErrorT e m b #

(>>) :: ErrorT e m a -> ErrorT e m b -> ErrorT e m b #

return :: a -> ErrorT e m a #

fail :: String -> ErrorT e m a #

Monad m => Monad (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

(>>=) :: StateT s m a -> (a -> StateT s m b) -> StateT s m b #

(>>) :: StateT s m a -> StateT s m b -> StateT s m b #

return :: a -> StateT s m a #

fail :: String -> StateT s m a #

Monad m => Monad (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

(>>=) :: StateT s m a -> (a -> StateT s m b) -> StateT s m b #

(>>) :: StateT s m a -> StateT s m b -> StateT s m b #

return :: a -> StateT s m a #

fail :: String -> StateT s m a #

(Monoid w, Monad m) => Monad (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Lazy

Methods

(>>=) :: WriterT w m a -> (a -> WriterT w m b) -> WriterT w m b #

(>>) :: WriterT w m a -> WriterT w m b -> WriterT w m b #

return :: a -> WriterT w m a #

fail :: String -> WriterT w m a #

(Monoid w, Monad m) => Monad (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Strict

Methods

(>>=) :: WriterT w m a -> (a -> WriterT w m b) -> WriterT w m b #

(>>) :: WriterT w m a -> WriterT w m b -> WriterT w m b #

return :: a -> WriterT w m a #

fail :: String -> WriterT w m a #

(Monoid w, Functor m, Monad m) => Monad (AccumT w m) 
Instance details

Defined in Control.Monad.Trans.Accum

Methods

(>>=) :: AccumT w m a -> (a -> AccumT w m b) -> AccumT w m b #

(>>) :: AccumT w m a -> AccumT w m b -> AccumT w m b #

return :: a -> AccumT w m a #

fail :: String -> AccumT w m a #

Monad m => Monad (SelectT r m) 
Instance details

Defined in Control.Monad.Trans.Select

Methods

(>>=) :: SelectT r m a -> (a -> SelectT r m b) -> SelectT r m b #

(>>) :: SelectT r m a -> SelectT r m b -> SelectT r m b #

return :: a -> SelectT r m a #

fail :: String -> SelectT r m a #

Monad ((->) r :: Type -> Type)

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

(>>=) :: (r -> a) -> (a -> r -> b) -> r -> b #

(>>) :: (r -> a) -> (r -> b) -> r -> b #

return :: a -> r -> a #

fail :: String -> r -> a #

(Monad f, Monad g) => Monad (f :*: g)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(>>=) :: (f :*: g) a -> (a -> (f :*: g) b) -> (f :*: g) b #

(>>) :: (f :*: g) a -> (f :*: g) b -> (f :*: g) b #

return :: a -> (f :*: g) a #

fail :: String -> (f :*: g) a #

(Monad f, Monad g) => Monad (Product f g)

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Product

Methods

(>>=) :: Product f g a -> (a -> Product f g b) -> Product f g b #

(>>) :: Product f g a -> Product f g b -> Product f g b #

return :: a -> Product f g a #

fail :: String -> Product f g a #

(Monad f, Applicative f) => Monad (WhenMatched f x y)

Equivalent to ReaderT Key (ReaderT x (ReaderT y (MaybeT f)))

Since: containers-0.5.9

Instance details

Defined in Data.IntMap.Internal

Methods

(>>=) :: WhenMatched f x y a -> (a -> WhenMatched f x y b) -> WhenMatched f x y b #

(>>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b #

return :: a -> WhenMatched f x y a #

fail :: String -> WhenMatched f x y a #

(Applicative f, Monad f) => Monad (WhenMissing f k x)

Equivalent to ReaderT k (ReaderT x (MaybeT f)) .

Since: containers-0.5.9

Instance details

Defined in Data.Map.Internal

Methods

(>>=) :: WhenMissing f k x a -> (a -> WhenMissing f k x b) -> WhenMissing f k x b #

(>>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b #

return :: a -> WhenMissing f k x a #

fail :: String -> WhenMissing f k x a #

Monad (ContT r m) 
Instance details

Defined in Control.Monad.Trans.Cont

Methods

(>>=) :: ContT r m a -> (a -> ContT r m b) -> ContT r m b #

(>>) :: ContT r m a -> ContT r m b -> ContT r m b #

return :: a -> ContT r m a #

fail :: String -> ContT r m a #

Monad m => Monad (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

(>>=) :: ReaderT r m a -> (a -> ReaderT r m b) -> ReaderT r m b #

(>>) :: ReaderT r m a -> ReaderT r m b -> ReaderT r m b #

return :: a -> ReaderT r m a #

fail :: String -> ReaderT r m a #

Monad f => Monad (M1 i c f)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(>>=) :: M1 i c f a -> (a -> M1 i c f b) -> M1 i c f b #

(>>) :: M1 i c f a -> M1 i c f b -> M1 i c f b #

return :: a -> M1 i c f a #

fail :: String -> M1 i c f a #

(Monad f, Applicative f) => Monad (WhenMatched f k x y)

Equivalent to ReaderT k (ReaderT x (ReaderT y (MaybeT f)))

Since: containers-0.5.9

Instance details

Defined in Data.Map.Internal

Methods

(>>=) :: WhenMatched f k x y a -> (a -> WhenMatched f k x y b) -> WhenMatched f k x y b #

(>>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b #

return :: a -> WhenMatched f k x y a #

fail :: String -> WhenMatched f k x y a #

(Monoid w, Monad m) => Monad (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Lazy

Methods

(>>=) :: RWST r w s m a -> (a -> RWST r w s m b) -> RWST r w s m b #

(>>) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m b #

return :: a -> RWST r w s m a #

fail :: String -> RWST r w s m a #

(Monoid w, Monad m) => Monad (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Strict

Methods

(>>=) :: RWST r w s m a -> (a -> RWST r w s m b) -> RWST r w s m b #

(>>) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m b #

return :: a -> RWST r w s m a #

fail :: String -> RWST r w s m a #

class Functor (f :: Type -> Type) where #

The Functor class is used for types that can be mapped over. Instances of Functor should satisfy the following laws:

fmap id  ==  id
fmap (f . g)  ==  fmap f . fmap g

The instances of Functor for lists, Maybe and IO satisfy these laws.

Methods

fmap :: (a -> b) -> f a -> f b #

Instances
Functor []

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

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

(<$) :: a -> [b] -> [a] #

Functor Maybe

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> Maybe a -> Maybe b #

(<$) :: a -> Maybe b -> Maybe a #

Functor IO

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> IO a -> IO b #

(<$) :: a -> IO b -> IO a #

Functor Par1

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> Par1 a -> Par1 b #

(<$) :: a -> Par1 b -> Par1 a #

Functor Q 
Instance details

Defined in Language.Haskell.TH.Syntax

Methods

fmap :: (a -> b) -> Q a -> Q b #

(<$) :: a -> Q b -> Q a #

Functor Rose 
Instance details

Defined in Test.QuickCheck.Property

Methods

fmap :: (a -> b) -> Rose a -> Rose b #

(<$) :: a -> Rose b -> Rose a #

Functor Blind 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Blind a -> Blind b #

(<$) :: a -> Blind b -> Blind a #

Functor Fixed 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Fixed a -> Fixed b #

(<$) :: a -> Fixed b -> Fixed a #

Functor OrderedList 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> OrderedList a -> OrderedList b #

(<$) :: a -> OrderedList b -> OrderedList a #

Functor NonEmptyList 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> NonEmptyList a -> NonEmptyList b #

(<$) :: a -> NonEmptyList b -> NonEmptyList a #

Functor SortedList 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> SortedList a -> SortedList b #

(<$) :: a -> SortedList b -> SortedList a #

Functor Positive 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Positive a -> Positive b #

(<$) :: a -> Positive b -> Positive a #

Functor Negative 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Negative a -> Negative b #

(<$) :: a -> Negative b -> Negative a #

Functor NonZero 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> NonZero a -> NonZero b #

(<$) :: a -> NonZero b -> NonZero a #

Functor NonNegative 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> NonNegative a -> NonNegative b #

(<$) :: a -> NonNegative b -> NonNegative a #

Functor NonPositive 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> NonPositive a -> NonPositive b #

(<$) :: a -> NonPositive b -> NonPositive a #

Functor Large 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Large a -> Large b #

(<$) :: a -> Large b -> Large a #

Functor Small 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Small a -> Small b #

(<$) :: a -> Small b -> Small a #

Functor Shrink2 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Shrink2 a -> Shrink2 b #

(<$) :: a -> Shrink2 b -> Shrink2 a #

Functor Smart 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Smart a -> Smart b #

(<$) :: a -> Smart b -> Smart a #

Functor Gen 
Instance details

Defined in Test.QuickCheck.Gen

Methods

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

(<$) :: a -> Gen b -> Gen a #

Functor Async 
Instance details

Defined in Control.Concurrent.Async

Methods

fmap :: (a -> b) -> Async a -> Async b #

(<$) :: a -> Async b -> Async a #

Functor Concurrently 
Instance details

Defined in Control.Concurrent.Async

Methods

fmap :: (a -> b) -> Concurrently a -> Concurrently b #

(<$) :: a -> Concurrently b -> Concurrently a #

Functor Complex

Since: base-4.9.0.0

Instance details

Defined in Data.Complex

Methods

fmap :: (a -> b) -> Complex a -> Complex b #

(<$) :: a -> Complex b -> Complex a #

Functor Min

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Min a -> Min b #

(<$) :: a -> Min b -> Min a #

Functor Max

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Max a -> Max b #

(<$) :: a -> Max b -> Max a #

Functor First

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> First a -> First b #

(<$) :: a -> First b -> First a #

Functor Last

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Last a -> Last b #

(<$) :: a -> Last b -> Last a #

Functor Option

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Option a -> Option b #

(<$) :: a -> Option b -> Option a #

Functor ZipList

Since: base-2.1

Instance details

Defined in Control.Applicative

Methods

fmap :: (a -> b) -> ZipList a -> ZipList b #

(<$) :: a -> ZipList b -> ZipList a #

Functor Identity

Since: base-4.8.0.0

Instance details

Defined in Data.Functor.Identity

Methods

fmap :: (a -> b) -> Identity a -> Identity b #

(<$) :: a -> Identity b -> Identity a #

Functor Handler

Since: base-4.6.0.0

Instance details

Defined in Control.Exception

Methods

fmap :: (a -> b) -> Handler a -> Handler b #

(<$) :: a -> Handler b -> Handler a #

Functor STM

Since: base-4.3.0.0

Instance details

Defined in GHC.Conc.Sync

Methods

fmap :: (a -> b) -> STM a -> STM b #

(<$) :: a -> STM b -> STM a #

Functor First

Since: base-4.8.0.0

Instance details

Defined in Data.Monoid

Methods

fmap :: (a -> b) -> First a -> First b #

(<$) :: a -> First b -> First a #

Functor Last

Since: base-4.8.0.0

Instance details

Defined in Data.Monoid

Methods

fmap :: (a -> b) -> Last a -> Last b #

(<$) :: a -> Last b -> Last a #

Functor Dual

Since: base-4.8.0.0

Instance details

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Dual a -> Dual b #

(<$) :: a -> Dual b -> Dual a #

Functor Sum

Since: base-4.8.0.0

Instance details

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Sum a -> Sum b #

(<$) :: a -> Sum b -> Sum a #

Functor Product

Since: base-4.8.0.0

Instance details

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Product a -> Product b #

(<$) :: a -> Product b -> Product a #

Functor Down

Since: base-4.11.0.0

Instance details

Defined in Data.Ord

Methods

fmap :: (a -> b) -> Down a -> Down b #

(<$) :: a -> Down b -> Down a #

Functor ReadP

Since: base-2.1

Instance details

Defined in Text.ParserCombinators.ReadP

Methods

fmap :: (a -> b) -> ReadP a -> ReadP b #

(<$) :: a -> ReadP b -> ReadP a #

Functor NonEmpty

Since: base-4.9.0.0

Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> NonEmpty a -> NonEmpty b #

(<$) :: a -> NonEmpty b -> NonEmpty a #

Functor IntMap 
Instance details

Defined in Data.IntMap.Internal

Methods

fmap :: (a -> b) -> IntMap a -> IntMap b #

(<$) :: a -> IntMap b -> IntMap a #

Functor Tree 
Instance details

Defined in Data.Tree

Methods

fmap :: (a -> b) -> Tree a -> Tree b #

(<$) :: a -> Tree b -> Tree a #

Functor Seq 
Instance details

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> Seq a -> Seq b #

(<$) :: a -> Seq b -> Seq a #

Functor FingerTree 
Instance details

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> FingerTree a -> FingerTree b #

(<$) :: a -> FingerTree b -> FingerTree a #

Functor Digit 
Instance details

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> Digit a -> Digit b #

(<$) :: a -> Digit b -> Digit a #

Functor Node 
Instance details

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> Node a -> Node b #

(<$) :: a -> Node b -> Node a #

Functor Elem 
Instance details

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> Elem a -> Elem b #

(<$) :: a -> Elem b -> Elem a #

Functor ViewL 
Instance details

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> ViewL a -> ViewL b #

(<$) :: a -> ViewL b -> ViewL a #

Functor ViewR 
Instance details

Defined in Data.Sequence.Internal

Methods

fmap :: (a -> b) -> ViewR a -> ViewR b #

(<$) :: a -> ViewR b -> ViewR a #

Functor Vector 
Instance details

Defined in Data.Vector

Methods

fmap :: (a -> b) -> Vector a -> Vector b #

(<$) :: a -> Vector b -> Vector a #

Functor Box 
Instance details

Defined in Data.Vector.Fusion.Util

Methods

fmap :: (a -> b) -> Box a -> Box b #

(<$) :: a -> Box b -> Box a #

Functor Id 
Instance details

Defined in Data.Vector.Fusion.Util

Methods

fmap :: (a -> b) -> Id a -> Id b #

(<$) :: a -> Id b -> Id a #

Functor Value 
Instance details

Defined in Data.Massiv.Array.Stencil.Internal

Methods

fmap :: (a -> b) -> Value a -> Value b #

(<$) :: a -> Value b -> Value a #

Functor Doc 
Instance details

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

fmap :: (a -> b) -> Doc a -> Doc b #

(<$) :: a -> Doc b -> Doc a #

Functor AnnotDetails 
Instance details

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

fmap :: (a -> b) -> AnnotDetails a -> AnnotDetails b #

(<$) :: a -> AnnotDetails b -> AnnotDetails a #

Functor Span 
Instance details

Defined in Text.PrettyPrint.Annotated.HughesPJ

Methods

fmap :: (a -> b) -> Span a -> Span b #

(<$) :: a -> Span b -> Span a #

Functor SmallArray 
Instance details

Defined in Data.Primitive.SmallArray

Methods

fmap :: (a -> b) -> SmallArray a -> SmallArray b #

(<$) :: a -> SmallArray b -> SmallArray a #

Functor Array 
Instance details

Defined in Data.Primitive.Array

Methods

fmap :: (a -> b) -> Array a -> Array b #

(<$) :: a -> Array b -> Array a #

Functor Results 
Instance details

Defined in Control.Scheduler.Internal

Methods

fmap :: (a -> b) -> Results a -> Results b #

(<$) :: a -> Results b -> Results a #

Functor Flat 
Instance details

Defined in UnliftIO.Internals.Async

Methods

fmap :: (a -> b) -> Flat a -> Flat b #

(<$) :: a -> Flat b -> Flat a #

Functor FlatApp 
Instance details

Defined in UnliftIO.Internals.Async

Methods

fmap :: (a -> b) -> FlatApp a -> FlatApp b #

(<$) :: a -> FlatApp b -> FlatApp a #

Functor P

Since: base-4.8.0.0

Instance details

Defined in Text.ParserCombinators.ReadP

Methods

fmap :: (a -> b) -> P a -> P b #

(<$) :: a -> P b -> P a #

Functor (Either a)

Since: base-3.0

Instance details

Defined in Data.Either

Methods

fmap :: (a0 -> b) -> Either a a0 -> Either a b #

(<$) :: a0 -> Either a b -> Either a a0 #

Functor (V1 :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> V1 a -> V1 b #

(<$) :: a -> V1 b -> V1 a #

Functor (U1 :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> U1 a -> U1 b #

(<$) :: a -> U1 b -> U1 a #

Functor ((,) a)

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

fmap :: (a0 -> b) -> (a, a0) -> (a, b) #

(<$) :: a0 -> (a, b) -> (a, a0) #

Functor (ST s)

Since: base-2.1

Instance details

Defined in GHC.ST

Methods

fmap :: (a -> b) -> ST s a -> ST s b #

(<$) :: a -> ST s b -> ST s a #

Functor (PropertyM m) 
Instance details

Defined in Test.QuickCheck.Monadic

Methods

fmap :: (a -> b) -> PropertyM m a -> PropertyM m b #

(<$) :: a -> PropertyM m b -> PropertyM m a #

Functor ((:->) a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

fmap :: (a0 -> b) -> (a :-> a0) -> a :-> b #

(<$) :: a0 -> (a :-> b) -> a :-> a0 #

Functor (Fun a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

fmap :: (a0 -> b) -> Fun a a0 -> Fun a b #

(<$) :: a0 -> Fun a b -> Fun a a0 #

Functor (Shrinking s) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Shrinking s a -> Shrinking s b #

(<$) :: a -> Shrinking s b -> Shrinking s a #

Functor (Array i)

Since: base-2.1

Instance details

Defined in GHC.Arr

Methods

fmap :: (a -> b) -> Array i a -> Array i b #

(<$) :: a -> Array i b -> Array i a #

Functor (Arg a)

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

fmap :: (a0 -> b) -> Arg a a0 -> Arg a b #

(<$) :: a0 -> Arg a b -> Arg a a0 #

Monad m => Functor (WrappedMonad m)

Since: base-2.1

Instance details

Defined in Control.Applicative

Methods

fmap :: (a -> b) -> WrappedMonad m a -> WrappedMonad m b #

(<$) :: a -> WrappedMonad m b -> WrappedMonad m a #

Arrow a => Functor (ArrowMonad a)

Since: base-4.6.0.0

Instance details

Defined in Control.Arrow

Methods

fmap :: (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b #

(<$) :: a0 -> ArrowMonad a b -> ArrowMonad a a0 #

Functor (Proxy :: Type -> Type)

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

fmap :: (a -> b) -> Proxy a -> Proxy b #

(<$) :: a -> Proxy b -> Proxy a #

Functor (Map k) 
Instance details

Defined in Data.Map.Internal

Methods

fmap :: (a -> b) -> Map k a -> Map k b #

(<$) :: a -> Map k b -> Map k a #

Functor m => Functor (MaybeT m) 
Instance details

Defined in Control.Monad.Trans.Maybe

Methods

fmap :: (a -> b) -> MaybeT m a -> MaybeT m b #

(<$) :: a -> MaybeT m b -> MaybeT m a #

Monad m => Functor (Handler m) 
Instance details

Defined in Control.Monad.Catch

Methods

fmap :: (a -> b) -> Handler m a -> Handler m b #

(<$) :: a -> Handler m b -> Handler m a #

Functor (SpecM a) 
Instance details

Defined in Test.Hspec.Core.Spec.Monad

Methods

fmap :: (a0 -> b) -> SpecM a a0 -> SpecM a b #

(<$) :: a0 -> SpecM a b -> SpecM a a0 #

Functor (Window ix) 
Instance details

Defined in Data.Massiv.Array.Delayed.Windowed

Methods

fmap :: (a -> b) -> Window ix a -> Window ix b #

(<$) :: a -> Window ix b -> Window ix a #

Functor m => Functor (ListT m) 
Instance details

Defined in Control.Monad.Trans.List

Methods

fmap :: (a -> b) -> ListT m a -> ListT m b #

(<$) :: a -> ListT m b -> ListT m a #

Monad m => Functor (Concurrently m)

Since: unliftio-0.1.0.0

Instance details

Defined in UnliftIO.Internals.Async

Methods

fmap :: (a -> b) -> Concurrently m a -> Concurrently m b #

(<$) :: a -> Concurrently m b -> Concurrently m a #

Functor m => Functor (Conc m) 
Instance details

Defined in UnliftIO.Internals.Async

Methods

fmap :: (a -> b) -> Conc m a -> Conc m b #

(<$) :: a -> Conc m b -> Conc m a #

Functor (Step s) 
Instance details

Defined in Data.Vector.Fusion.Stream.Monadic

Methods

fmap :: (a -> b) -> Step s a -> Step s b #

(<$) :: a -> Step s b -> Step s a #

Monad m => Functor (Stream m) 
Instance details

Defined in Data.Vector.Fusion.Stream.Monadic

Methods

fmap :: (a -> b) -> Stream m a -> Stream m b #

(<$) :: a -> Stream m b -> Stream m a #

Functor f => Functor (Rec1 f)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> Rec1 f a -> Rec1 f b #

(<$) :: a -> Rec1 f b -> Rec1 f a #

Functor (URec Char :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Char a -> URec Char b #

(<$) :: a -> URec Char b -> URec Char a #

Functor (URec Double :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Double a -> URec Double b #

(<$) :: a -> URec Double b -> URec Double a #

Functor (URec Float :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Float a -> URec Float b #

(<$) :: a -> URec Float b -> URec Float a #

Functor (URec Int :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Int a -> URec Int b #

(<$) :: a -> URec Int b -> URec Int a #

Functor (URec Word :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Word a -> URec Word b #

(<$) :: a -> URec Word b -> URec Word a #

Functor (URec (Ptr ()) :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec (Ptr ()) a -> URec (Ptr ()) b #

(<$) :: a -> URec (Ptr ()) b -> URec (Ptr ()) a #

Arrow a => Functor (WrappedArrow a b)

Since: base-2.1

Instance details

Defined in Control.Applicative

Methods

fmap :: (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 #

(<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 #

Functor (Const m :: Type -> Type)

Since: base-2.1

Instance details

Defined in Data.Functor.Const

Methods

fmap :: (a -> b) -> Const m a -> Const m b #

(<$) :: a -> Const m b -> Const m a #

Functor f => Functor (Ap f)

Since: base-4.12.0.0

Instance details

Defined in Data.Monoid

Methods

fmap :: (a -> b) -> Ap f a -> Ap f b #

(<$) :: a -> Ap f b -> Ap f a #

Functor f => Functor (Alt f)

Since: base-4.8.0.0

Instance details

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Alt f a -> Alt f b #

(<$) :: a -> Alt f b -> Alt f a #

(Applicative f, Monad f) => Functor (WhenMissing f x)

Since: containers-0.5.9

Instance details

Defined in Data.IntMap.Internal

Methods

fmap :: (a -> b) -> WhenMissing f x a -> WhenMissing f x b #

(<$) :: a -> WhenMissing f x b -> WhenMissing f x a #

Functor m => Functor (ExceptT e m) 
Instance details

Defined in Control.Monad.Trans.Except

Methods

fmap :: (a -> b) -> ExceptT e m a -> ExceptT e m b #

(<$) :: a -> ExceptT e m b -> ExceptT e m a #

Functor (Stencil ix e) 
Instance details

Defined in Data.Massiv.Array.Stencil.Internal

Methods

fmap :: (a -> b) -> Stencil ix e a -> Stencil ix e b #

(<$) :: a -> Stencil ix e b -> Stencil ix e a #

Functor (Array DI ix) 
Instance details

Defined in Data.Massiv.Array.Delayed.Interleaved

Methods

fmap :: (a -> b) -> Array DI ix a -> Array DI ix b #

(<$) :: a -> Array DI ix b -> Array DI ix a #

Functor (Array DW ix) 
Instance details

Defined in Data.Massiv.Array.Delayed.Windowed

Methods

fmap :: (a -> b) -> Array DW ix a -> Array DW ix b #

(<$) :: a -> Array DW ix b -> Array DW ix a #

Index ix => Functor (Array B ix) 
Instance details

Defined in Data.Massiv.Array.Manifest.Boxed

Methods

fmap :: (a -> b) -> Array B ix a -> Array B ix b #

(<$) :: a -> Array B ix b -> Array B ix a #

Functor (Array DS Ix1) 
Instance details

Defined in Data.Massiv.Array.Delayed.Stream

Methods

fmap :: (a -> b) -> Array DS Ix1 a -> Array DS Ix1 b #

(<$) :: a -> Array DS Ix1 b -> Array DS Ix1 a #

Functor (Array D ix) 
Instance details

Defined in Data.Massiv.Array.Delayed.Pull

Methods

fmap :: (a -> b) -> Array D ix a -> Array D ix b #

(<$) :: a -> Array D ix b -> Array D ix a #

Functor (Array DL ix) 
Instance details

Defined in Data.Massiv.Array.Delayed.Push

Methods

fmap :: (a -> b) -> Array DL ix a -> Array DL ix b #

(<$) :: a -> Array DL ix b -> Array DL ix a #

Functor m => Functor (IdentityT m) 
Instance details

Defined in Control.Monad.Trans.Identity

Methods

fmap :: (a -> b) -> IdentityT m a -> IdentityT m b #

(<$) :: a -> IdentityT m b -> IdentityT m a #

Functor m => Functor (ErrorT e m) 
Instance details

Defined in Control.Monad.Trans.Error

Methods

fmap :: (a -> b) -> ErrorT e m a -> ErrorT e m b #

(<$) :: a -> ErrorT e m b -> ErrorT e m a #

Functor m => Functor (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Lazy

Methods

fmap :: (a -> b) -> StateT s m a -> StateT s m b #

(<$) :: a -> StateT s m b -> StateT s m a #

Functor m => Functor (StateT s m) 
Instance details

Defined in Control.Monad.Trans.State.Strict

Methods

fmap :: (a -> b) -> StateT s m a -> StateT s m b #

(<$) :: a -> StateT s m b -> StateT s m a #

Functor m => Functor (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Lazy

Methods

fmap :: (a -> b) -> WriterT w m a -> WriterT w m b #

(<$) :: a -> WriterT w m b -> WriterT w m a #

Functor m => Functor (WriterT w m) 
Instance details

Defined in Control.Monad.Trans.Writer.Strict

Methods

fmap :: (a -> b) -> WriterT w m a -> WriterT w m b #

(<$) :: a -> WriterT w m b -> WriterT w m a #

Functor (Constant a :: Type -> Type) 
Instance details

Defined in Data.Functor.Constant

Methods

fmap :: (a0 -> b) -> Constant a a0 -> Constant a b #

(<$) :: a0 -> Constant a b -> Constant a a0 #

Functor m => Functor (AccumT w m) 
Instance details

Defined in Control.Monad.Trans.Accum

Methods

fmap :: (a -> b) -> AccumT w m a -> AccumT w m b #

(<$) :: a -> AccumT w m b -> AccumT w m a #

Functor m => Functor (SelectT r m) 
Instance details

Defined in Control.Monad.Trans.Select

Methods

fmap :: (a -> b) -> SelectT r m a -> SelectT r m b #

(<$) :: a -> SelectT r m b -> SelectT r m a #

Monad m => Functor (Bundle m v) 
Instance details

Defined in Data.Vector.Fusion.Bundle.Monadic

Methods

fmap :: (a -> b) -> Bundle m v a -> Bundle m v b #

(<$) :: a -> Bundle m v b -> Bundle m v a #

Functor ((->) r :: Type -> Type)

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> (r -> a) -> r -> b #

(<$) :: a -> (r -> b) -> r -> a #

Functor (K1 i c :: Type -> Type)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> K1 i c a -> K1 i c b #

(<$) :: a -> K1 i c b -> K1 i c a #

(Functor f, Functor g) => Functor (f :+: g)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> (f :+: g) a -> (f :+: g) b #

(<$) :: a -> (f :+: g) b -> (f :+: g) a #

(Functor f, Functor g) => Functor (f :*: g)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> (f :*: g) a -> (f :*: g) b #

(<$) :: a -> (f :*: g) b -> (f :*: g) a #

(Functor f, Functor g) => Functor (Product f g)

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Product

Methods

fmap :: (a -> b) -> Product f g a -> Product f g b #

(<$) :: a -> Product f g b -> Product f g a #

(Functor f, Functor g) => Functor (Sum f g)

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Sum

Methods

fmap :: (a -> b) -> Sum f g a -> Sum f g b #

(<$) :: a -> Sum f g b -> Sum f g a #

Functor f => Functor (WhenMatched f x y)

Since: containers-0.5.9

Instance details

Defined in Data.IntMap.Internal

Methods

fmap :: (a -> b) -> WhenMatched f x y a -> WhenMatched f x y b #

(<$) :: a -> WhenMatched f x y b -> WhenMatched f x y a #

(Applicative f, Monad f) => Functor (WhenMissing f k x)

Since: containers-0.5.9

Instance details

Defined in Data.Map.Internal

Methods

fmap :: (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b #

(<$) :: a -> WhenMissing f k x b -> WhenMissing f k x a #

Functor (ContT r m) 
Instance details

Defined in Control.Monad.Trans.Cont

Methods

fmap :: (a -> b) -> ContT r m a -> ContT r m b #

(<$) :: a -> ContT r m b -> ContT r m a #

Functor m => Functor (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

fmap :: (a -> b) -> ReaderT r m a -> ReaderT r m b #

(<$) :: a -> ReaderT r m b -> ReaderT r m a #

Functor f => Functor (M1 i c f)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> M1 i c f a -> M1 i c f b #

(<$) :: a -> M1 i c f b -> M1 i c f a #

(Functor f, Functor g) => Functor (f :.: g)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> (f :.: g) a -> (f :.: g) b #

(<$) :: a -> (f :.: g) b -> (f :.: g) a #

(Functor f, Functor g) => Functor (Compose f g)

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Compose

Methods

fmap :: (a -> b) -> Compose f g a -> Compose f g b #

(<$) :: a -> Compose f g b -> Compose f g a #

Functor f => Functor (WhenMatched f k x y)

Since: containers-0.5.9

Instance details

Defined in Data.Map.Internal

Methods

fmap :: (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b #

(<$) :: a -> WhenMatched f k x y b -> WhenMatched f k x y a #

Functor m => Functor (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Lazy

Methods

fmap :: (a -> b) -> RWST r w s m a -> RWST r w s m b #

(<$) :: a -> RWST r w s m b -> RWST r w s m a #

Functor m => Functor (RWST r w s m) 
Instance details

Defined in Control.Monad.Trans.RWS.Strict

Methods

fmap :: (a -> b) -> RWST r w s m a -> RWST r w s m b #

(<$) :: a -> RWST r w s m b -> RWST r w s m a #

class Typeable (a :: k) #

The class Typeable allows a concrete representation of a type to be calculated.

Minimal complete definition

typeRep#

mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b) #

Map each element of a structure to a monadic action, evaluate these actions from left to right, and collect the results. For a version that ignores the results see mapM_.

sequence :: (Traversable t, Monad m) => t (m a) -> m (t a) #

Evaluate each monadic action in the structure from left to right, and collect the results. For a version that ignores the results see sequence_.

data RealWorld :: Type #

RealWorld is deeply magical. It is primitive, but it is not unlifted (hence ptrArg). We never manipulate values of type RealWorld; it's only used in the type system, to parameterise State#.

data TyCon #

Instances
Eq TyCon 
Instance details

Defined in GHC.Classes

Methods

(==) :: TyCon -> TyCon -> Bool #

(/=) :: TyCon -> TyCon -> Bool #

Ord TyCon 
Instance details

Defined in GHC.Classes

Methods

compare :: TyCon -> TyCon -> Ordering #

(<) :: TyCon -> TyCon -> Bool #

(<=) :: TyCon -> TyCon -> Bool #

(>) :: TyCon -> TyCon -> Bool #

(>=) :: TyCon -> TyCon -> Bool #

max :: TyCon -> TyCon -> TyCon #

min :: TyCon -> TyCon -> TyCon #

Show TyCon

Since: base-2.1

Instance details

Defined in GHC.Show

Methods

showsPrec :: Int -> TyCon -> ShowS #

show :: TyCon -> String #

showList :: [TyCon] -> ShowS #

NFData TyCon

NOTE: Prior to deepseq-1.4.4.0 this instance was only defined for base-4.8.0.0 and later.

Since: deepseq-1.4.0.0

Instance details

Defined in Control.DeepSeq

Methods

rnf :: TyCon -> () #

data ST s a #

The strict state-transformer monad. A computation of type ST s a transforms an internal state indexed by s, and returns a value of type a. The s parameter is either

  • an uninstantiated type variable (inside invocations of runST), or
  • RealWorld (inside invocations of stToIO).

It serves to keep the internal states of different invocations of runST separate from each other and from invocations of stToIO.

The >>= and >> operations are strict in the state (though not in values stored in the state). For example,

runST (writeSTRef _|_ v >>= f) = _|_
Instances
Monad (ST s)

Since: base-2.1

Instance details

Defined in GHC.ST

Methods

(>>=) :: ST s a -> (a -> ST s b) -> ST s b #

(>>) :: ST s a -> ST s b -> ST s b #

return :: a -> ST s a #

fail :: String -> ST s a #

Functor (ST s)

Since: base-2.1

Instance details

Defined in GHC.ST

Methods

fmap :: (a -> b) -> ST s a -> ST s b #

(<$) :: a -> ST s b -> ST s a #

MonadFail (ST s)

Since: base-4.11.0.0

Instance details

Defined in GHC.ST

Methods

fail :: String -> ST s a #

Applicative (ST s)

Since: base-4.4.0.0

Instance details

Defined in GHC.ST

Methods

pure :: a -> ST s a #

(<*>) :: ST s (a -> b) -> ST s a -> ST s b #

liftA2 :: (a -> b -> c) -> ST s a -> ST s b -> ST s c #

(*>) :: ST s a -> ST s b -> ST s b #

(<*) :: ST s a -> ST s b -> ST s a #

MonadThrow (ST s) 
Instance details

Defined in Control.Monad.Catch

Methods

throwM :: Exception e => e -> ST s a #

PrimMonad (ST s) 
Instance details

Defined in Control.Monad.Primitive

Associated Types

type PrimState (ST s) :: Type #

Methods

primitive :: (State# (PrimState (ST s)) -> (#State# (PrimState (ST s)), a#)) -> ST s a #

PrimBase (ST s) 
Instance details

Defined in Control.Monad.Primitive

Methods

internal :: ST s a -> State# (PrimState (ST s)) -> (#State# (PrimState (ST s)), a#) #

Show (ST s a)

Since: base-2.1

Instance details

Defined in GHC.ST

Methods

showsPrec :: Int -> ST s a -> ShowS #

show :: ST s a -> String #

showList :: [ST s a] -> ShowS #

Semigroup a => Semigroup (ST s a)

Since: base-4.11.0.0

Instance details

Defined in GHC.ST

Methods

(<>) :: ST s a -> ST s a -> ST s a #

sconcat :: NonEmpty (ST s a) -> ST s a #

stimes :: Integral b => b -> ST s a -> ST s a #

Monoid a => Monoid (ST s a)

Since: base-4.11.0.0

Instance details

Defined in GHC.ST

Methods

mempty :: ST s a #

mappend :: ST s a -> ST s a -> ST s a #

mconcat :: [ST s a] -> ST s a #

type PrimState (ST s) 
Instance details

Defined in Control.Monad.Primitive

type PrimState (ST s) = s

labelledExamplesWithResult :: Testable prop => Args -> prop -> IO Result #

A variant of labelledExamples that takes test arguments and returns a result.

labelledExamplesResult :: Testable prop => prop -> IO Result #

A variant of labelledExamples that returns a result.

labelledExamplesWith :: Testable prop => Args -> prop -> IO () #

A variant of labelledExamples that takes test arguments.

labelledExamples :: Testable prop => prop -> IO () #

Given a property, which must use label, collect, classify or cover to associate labels with test cases, find an example test case for each possible label. The example test cases are minimised using shrinking.

For example, suppose we test delete x xs and record the number of times that x occurs in xs:

prop_delete :: Int -> [Int] -> Property
prop_delete x xs =
  classify (count x xs == 0) "count x xs == 0" $
  classify (count x xs == 1) "count x xs == 1" $
  classify (count x xs >= 2) "count x xs >= 2" $
  counterexample (show (delete x xs)) $
  count x (delete x xs) == max 0 (count x xs-1)
  where count x xs = length (filter (== x) xs)

labelledExamples generates three example test cases, one for each label:

>>> labelledExamples prop_delete
*** Found example of count x xs == 0
0
[]
[]

*** Found example of count x xs == 1
0
[0]
[]

*** Found example of count x xs >= 2
5
[5,5]
[5]

+++ OK, passed 100 tests:
78% count x xs == 0
21% count x xs == 1
 1% count x xs >= 2

verboseCheckAll :: Q Exp #

Test all properties in the current module. This is just a convenience function that combines quickCheckAll and verbose.

verboseCheckAll has the same issue with scoping as quickCheckAll: see the note there about return [].

quickCheckAll :: Q Exp #

Test all properties in the current module. The name of the property must begin with prop_. Polymorphic properties will be defaulted to Integer. Returns True if all tests succeeded, False otherwise.

To use quickCheckAll, add a definition to your module along the lines of

return []
runTests = $quickCheckAll

and then execute runTests.

Note: the bizarre return [] in the example above is needed on GHC 7.8 and later; without it, quickCheckAll will not be able to find any of the properties. For the curious, the return [] is a Template Haskell splice that makes GHC insert the empty list of declarations at that point in the program; GHC typechecks everything before the return [] before it starts on the rest of the module, which means that the later call to quickCheckAll can see everything that was defined before the return []. Yikes!

allProperties :: Q Exp #

List all properties in the current module.

$allProperties has type [(String, Property)].

allProperties has the same issue with scoping as quickCheckAll: see the note there about return [].

forAllProperties :: Q Exp #

Test all properties in the current module, using a custom quickCheck function. The same caveats as with quickCheckAll apply.

$forAllProperties has type (Property -> IO Result) -> IO Bool. An example invocation is $forAllProperties quickCheckResult, which does the same thing as $quickCheckAll.

forAllProperties has the same issue with scoping as quickCheckAll: see the note there about return [].

monomorphic :: Name -> ExpQ #

Monomorphise an arbitrary property by defaulting all type variables to Integer.

For example, if f has type Ord a => [a] -> [a] then $(monomorphic 'f) has type [Integer] -> [Integer].

If you want to use monomorphic in the same file where you defined the property, the same scoping problems pop up as in quickCheckAll: see the note there about return [].

polyVerboseCheck :: Name -> ExpQ #

Test a polymorphic property, defaulting all type variables to Integer. This is just a convenience function that combines verboseCheck and monomorphic.

If you want to use polyVerboseCheck in the same file where you defined the property, the same scoping problems pop up as in quickCheckAll: see the note there about return [].

polyQuickCheck :: Name -> ExpQ #

Test a polymorphic property, defaulting all type variables to Integer.

Invoke as $(polyQuickCheck 'prop), where prop is a property. Note that just evaluating quickCheck prop in GHCi will seem to work, but will silently default all type variables to ()!

$(polyQuickCheck 'prop) means the same as quickCheck $(monomorphic 'prop). If you want to supply custom arguments to polyQuickCheck, you will have to combine quickCheckWith and monomorphic yourself.

If you want to use polyQuickCheck in the same file where you defined the property, the same scoping problems pop up as in quickCheckAll: see the note there about return [].

runSTGen :: (forall s. Gen (ST s a)) -> Gen a #

monadicST :: Testable a => (forall s. PropertyM (ST s) a) -> Property #

Runs the property monad for ST-computations.

-- Your mutable sorting algorithm here
sortST :: Ord a => [a] -> ST s (MVector s a)
sortST = thaw . fromList . sort

prop_sortST xs = monadicST $ do
  sorted  <- run (freeze =<< sortST xs)
  assert (toList sorted == sort xs)
>>> quickCheck prop_sortST
+++ OK, passed 100 tests.

monadicIO :: Testable a => PropertyM IO a -> Property #

Runs the property monad for IO-computations.

prop_cat msg = monadicIO $ do
  (exitCode, stdout, _) <- run (readProcessWithExitCode "cat" [] msg)

  pre (ExitSuccess == exitCode)

  assert (stdout == msg)
>>> quickCheck prop_cat
+++ OK, passed 100 tests.

monadic' :: (Testable a, Monad m) => PropertyM m a -> Gen (m Property) #

monadic :: (Testable a, Monad m) => (m Property -> Property) -> PropertyM m a -> Property #

monitor :: Monad m => (Property -> Property) -> PropertyM m () #

Allows making observations about the test data:

monitor (collect e)

collects the distribution of value of e.

monitor (counterexample "Failure!")

Adds "Failure!" to the counterexamples.

forAllM :: (Monad m, Show a) => Gen a -> (a -> PropertyM m b) -> PropertyM m b #

Quantification in monadic properties to pick, with a notation similar to forAll. Note: values generated by forAllM do not shrink.

wp :: Monad m => m a -> (a -> PropertyM m b) -> PropertyM m b #

The weakest precondition

wp(x ← e, p)

can be expressed as in code as wp e (\x -> p).

pick :: (Monad m, Show a) => Gen a -> PropertyM m a #

Quantification in a monadic property, fits better with do-notation than forAllM. Note: values generated by pick do not shrink.

run :: Monad m => m a -> PropertyM m a #

The lifting operation of the property monad. Allows embedding monadic/IO-actions in properties:

log :: Int -> IO ()

prop_foo n = monadicIO $ do
  run (log n)
  -- ...

pre :: Monad m => Bool -> PropertyM m () #

Tests preconditions. Unlike assert this does not cause the property to fail, rather it discards them just like using the implication combinator ==>.

This allows representing the Hoare triple

{p} x ← e{q}

as

pre p
x <- run e
assert q

assert :: Monad m => Bool -> PropertyM m () #

Allows embedding non-monadic properties into monadic ones.

stop :: (Testable prop, Monad m) => prop -> PropertyM m a #

newtype PropertyM (m :: Type -> Type) a #

The property monad is really a monad transformer that can contain monadic computations in the monad m it is parameterized by:

  • m - the m-computations that may be performed within PropertyM

Elements of PropertyM m a may mix property operations and m-computations.

Constructors

MkPropertyM 

Fields

Instances
MonadTrans PropertyM 
Instance details

Defined in Test.QuickCheck.Monadic

Methods

lift :: Monad m => m a -> PropertyM m a #

Monad m => Monad (PropertyM m) 
Instance details

Defined in Test.QuickCheck.Monadic

Methods

(>>=) :: PropertyM m a -> (a -> PropertyM m b) -> PropertyM m b #

(>>) :: PropertyM m a -> PropertyM m b -> PropertyM m b #

return :: a -> PropertyM m a #

fail :: String -> PropertyM m a #

Functor (PropertyM m) 
Instance details

Defined in Test.QuickCheck.Monadic

Methods

fmap :: (a -> b) -> PropertyM m a -> PropertyM m b #

(<$) :: a -> PropertyM m b -> PropertyM m a #

Monad m => MonadFail (PropertyM m) 
Instance details

Defined in Test.QuickCheck.Monadic

Methods

fail :: String -> PropertyM m a #

Applicative (PropertyM m) 
Instance details

Defined in Test.QuickCheck.Monadic

Methods

pure :: a -> PropertyM m a #

(<*>) :: PropertyM m (a -> b) -> PropertyM m a -> PropertyM m b #

liftA2 :: (a -> b -> c) -> PropertyM m a -> PropertyM m b -> PropertyM m c #

(*>) :: PropertyM m a -> PropertyM m b -> PropertyM m b #

(<*) :: PropertyM m a -> PropertyM m b -> PropertyM m a #

MonadIO m => MonadIO (PropertyM m) 
Instance details

Defined in Test.QuickCheck.Monadic

Methods

liftIO :: IO a -> PropertyM m a #

verboseCheckWithResult :: Testable prop => Args -> prop -> IO Result #

Tests a property, using test arguments, produces a test result, and prints the results and all test cases generated to stdout. This is just a convenience function that combines quickCheckWithResult and verbose.

verboseCheckResult :: Testable prop => prop -> IO Result #

Tests a property, produces a test result, and prints the results and all test cases generated to stdout. This is just a convenience function that combines quickCheckResult and verbose.

verboseCheckWith :: Testable prop => Args -> prop -> IO () #

Tests a property, using test arguments, and prints the results and all test cases generated to stdout. This is just a convenience function that combines quickCheckWith and verbose.

verboseCheck :: Testable prop => prop -> IO () #

Tests a property and prints the results and all test cases generated to stdout. This is just a convenience function that means the same as quickCheck . verbose.

quickCheckWithResult :: Testable prop => Args -> prop -> IO Result #

Tests a property, using test arguments, produces a test result, and prints the results to stdout.

quickCheckResult :: Testable prop => prop -> IO Result #

Tests a property, produces a test result, and prints the results to stdout.

quickCheckWith :: Testable prop => Args -> prop -> IO () #

Tests a property, using test arguments, and prints the results to stdout.

quickCheck :: Testable prop => prop -> IO () #

Tests a property and prints the results to stdout.

By default up to 100 tests are performed, which may not be enough to find all bugs. To run more tests, use withMaxSuccess.

If you want to get the counterexample as a Haskell value, rather than just printing it, try the quickcheck-with-counterexamples package.

stdArgs :: Args #

The default test arguments

isSuccess :: Result -> Bool #

Check if the test run result was a success

data Args #

Args specifies arguments to the QuickCheck driver

Constructors

Args 

Fields

  • replay :: Maybe (QCGen, Int)

    Should we replay a previous test? Note: saving a seed from one version of QuickCheck and replaying it in another is not supported. If you want to store a test case permanently you should save the test case itself.

  • maxSuccess :: Int

    Maximum number of successful tests before succeeding. Testing stops at the first failure. If all tests are passing and you want to run more tests, increase this number.

  • maxDiscardRatio :: Int

    Maximum number of discarded tests per successful test before giving up

  • maxSize :: Int

    Size to use for the biggest test cases

  • chatty :: Bool

    Whether to print anything

  • maxShrinks :: Int

    Maximum number of shrinks to before giving up. Setting this to zero turns shrinking off.

Instances
Read Args 
Instance details

Defined in Test.QuickCheck.Test

Show Args 
Instance details

Defined in Test.QuickCheck.Test

Methods

showsPrec :: Int -> Args -> ShowS #

show :: Args -> String #

showList :: [Args] -> ShowS #

data Result #

Result represents the test result

Constructors

Success

A successful test run

Fields

GaveUp

Given up

Fields

Failure

A failed test run

Fields

NoExpectedFailure

A property that should have failed did not

Fields

Instances
Show Result 
Instance details

Defined in Test.QuickCheck.Test

total :: NFData a => a -> Property #

Checks that a value is total, i.e., doesn't crash when evaluated.

(=/=) :: (Eq a, Show a) => a -> a -> Property infix 4 #

Like /=, but prints a counterexample when it fails.

(===) :: (Eq a, Show a) => a -> a -> Property infix 4 #

Like ==, but prints a counterexample when it fails.

disjoin :: Testable prop => [prop] -> Property #

Take the disjunction of several properties.

(.||.) :: (Testable prop1, Testable prop2) => prop1 -> prop2 -> Property infixr 1 #

Disjunction: p1 .||. p2 passes unless p1 and p2 simultaneously fail.

conjoin :: Testable prop => [prop] -> Property #

Take the conjunction of several properties.

(.&&.) :: (Testable prop1, Testable prop2) => prop1 -> prop2 -> Property infixr 1 #

Conjunction: p1 .&&. p2 passes if both p1 and p2 pass.

forAllShrinkBlind :: Testable prop => Gen a -> (a -> [a]) -> (a -> prop) -> Property #

Like forAllShrink, but without printing the generated value.

forAllShrinkShow :: Testable prop => Gen a -> (a -> [a]) -> (a -> String) -> (a -> prop) -> Property #

Like forAllShrink, but with an explicitly given show function.

forAllShrink :: (Show a, Testable prop) => Gen a -> (a -> [a]) -> (a -> prop) -> Property #

Like forAll, but tries to shrink the argument for failing test cases.

forAllBlind :: Testable prop => Gen a -> (a -> prop) -> Property #

Like forAll, but without printing the generated value.

forAllShow :: Testable prop => Gen a -> (a -> String) -> (a -> prop) -> Property #

Like forAll, but with an explicitly given show function.

forAll :: (Show a, Testable prop) => Gen a -> (a -> prop) -> Property #

Explicit universal quantification: uses an explicitly given test case generator.

within :: Testable prop => Int -> prop -> Property #

Considers a property failed if it does not complete within the given number of microseconds.

Note: if the property times out, variables quantified inside the within will not be printed. Therefore, you should use within only in the body of your property.

Good: prop_foo a b c = within 1000000 ...

Bad: prop_foo = within 1000000 $ \a b c -> ...

Bad: prop_foo a b c = ...; main = quickCheck (within 1000000 prop_foo)

(==>) :: Testable prop => Bool -> prop -> Property infixr 0 #

Implication for properties: The resulting property holds if the first argument is False (in which case the test case is discarded), or if the given property holds. Note that using implication carelessly can severely skew test case distribution: consider using cover to make sure that your test data is still good quality.

coverTable :: Testable prop => String -> [(String, Double)] -> prop -> Property #

Checks that the values in a given table appear a certain proportion of the time. A call to coverTable table [(x1, p1), ..., (xn, pn)] asserts that of the values in table, x1 should appear at least p1 percent of the time, x2 at least p2 percent of the time, and so on.

Note: If the coverage check fails, QuickCheck prints out a warning, but the property does not fail. To make the property fail, use checkCoverage.

Continuing the example from the tabular combinator...

data Command = LogIn | LogOut | SendMessage String deriving (Data, Show)
prop_chatroom :: [Command] -> Property
prop_chatroom cmds =
  wellFormed cmds LoggedOut ==>
  'tabulate' "Commands" (map (show . 'Data.Data.toConstr') cmds) $
    ...

...we can add a coverage requirement as follows, which checks that LogIn, LogOut and SendMessage each occur at least 25% of the time:

prop_chatroom :: [Command] -> Property
prop_chatroom cmds =
  wellFormed cmds LoggedOut ==>
  coverTable "Commands" [("LogIn", 25), ("LogOut", 25), ("SendMessage", 25)] $
  'tabulate' "Commands" (map (show . 'Data.Data.toConstr') cmds) $
    ... property goes here ...
>>> quickCheck prop_chatroom
+++ OK, passed 100 tests; 2909 discarded:
56% 0
17% 1
10% 2
 6% 3
 5% 4
 3% 5
 3% 7

Commands (111 in total):
51.4% LogIn
30.6% SendMessage
18.0% LogOut

Table 'Commands' had only 18.0% LogOut, but expected 25.0%

tabulate :: Testable prop => String -> [String] -> prop -> Property #

Collects information about test case distribution into a table. The arguments to tabulate are the table's name and a list of values associated with the current test case. After testing, QuickCheck prints the frequency of all collected values. The frequencies are expressed as a percentage of the total number of values collected.

You should prefer tabulate to label when each test case is associated with a varying number of values. Here is a (not terribly useful) example, where the test data is a list of integers and we record all values that occur in the list:

prop_sorted_sort :: [Int] -> Property
prop_sorted_sort xs =
  sorted xs ==>
  tabulate "List elements" (map show xs) $
  sort xs === xs
>>> quickCheck prop_sorted_sort
+++ OK, passed 100 tests; 1684 discarded.

List elements (109 in total):
 3.7% 0
 3.7% 17
 3.7% 2
 3.7% 6
 2.8% -6
 2.8% -7

Here is a more useful example. We are testing a chatroom, where the user can log in, log out, or send a message:

data Command = LogIn | LogOut | SendMessage String deriving (Data, Show)
instance Arbitrary Command where ...

There are some restrictions on command sequences; for example, the user must log in before doing anything else. The function valid :: [Command] -> Bool checks that a command sequence is allowed. Our property then has the form:

prop_chatroom :: [Command] -> Property
prop_chatroom cmds =
  valid cmds ==>
    ...

The use of ==> may skew test case distribution. We use collect to see the length of the command sequences, and tabulate to get the frequencies of the individual commands:

prop_chatroom :: [Command] -> Property
prop_chatroom cmds =
  wellFormed cmds LoggedOut ==>
  'collect' (length cmds) $
  'tabulate' "Commands" (map (show . 'Data.Data.toConstr') cmds) $
    ...
>>> quickCheckWith stdArgs{maxDiscardRatio = 1000} prop_chatroom
+++ OK, passed 100 tests; 2775 discarded:
60% 0
20% 1
15% 2
 3% 3
 1% 4
 1% 5

Commands (68 in total):
62% LogIn
22% SendMessage
16% LogOut

cover #

Arguments

:: Testable prop 
=> Double

The required percentage (0-100) of test cases.

-> Bool

True if the test case belongs to the class.

-> String

Label for the test case class.

-> prop 
-> Property 

Checks that at least the given proportion of successful test cases belong to the given class. Discarded tests (i.e. ones with a false precondition) do not affect coverage.

Note: If the coverage check fails, QuickCheck prints out a warning, but the property does not fail. To make the property fail, use checkCoverage.

For example:

prop_sorted_sort :: [Int] -> Property
prop_sorted_sort xs =
  sorted xs ==>
  cover 50 (length xs > 1) "non-trivial" $
  sort xs === xs
>>> quickCheck prop_sorted_sort
+++ OK, passed 100 tests; 135 discarded (26% non-trivial).

Only 26% non-trivial, but expected 50%

classify #

Arguments

:: Testable prop 
=> Bool

True if the test case should be labelled.

-> String

Label.

-> prop 
-> Property 

Reports how many test cases satisfy a given condition.

For example:

prop_sorted_sort :: [Int] -> Property
prop_sorted_sort xs =
  sorted xs ==>
  classify (length xs > 1) "non-trivial" $
  sort xs === xs
>>> quickCheck prop_sorted_sort
+++ OK, passed 100 tests (22% non-trivial).

collect :: (Show a, Testable prop) => a -> prop -> Property #

Attaches a label to a test case. This is used for reporting test case distribution.

collect x = label (show x)

For example:

prop_reverse_reverse :: [Int] -> Property
prop_reverse_reverse xs =
  collect (length xs) $
    reverse (reverse xs) === xs
>>> quickCheck prop_reverse_reverse
+++ OK, passed 100 tests:
7% 7
6% 3
5% 4
4% 6
...

Each use of collect in your property results in a separate table of test case distribution in the output. If this is not what you want, use tabulate.

label :: Testable prop => String -> prop -> Property #

Attaches a label to a test case. This is used for reporting test case distribution.

For example:

prop_reverse_reverse :: [Int] -> Property
prop_reverse_reverse xs =
  label ("length of input is " ++ show (length xs)) $
    reverse (reverse xs) === xs
>>> quickCheck prop_reverse_reverse
+++ OK, passed 100 tests:
7% length of input is 7
6% length of input is 3
5% length of input is 4
4% length of input is 6
...

Each use of label in your property results in a separate table of test case distribution in the output. If this is not what you want, use tabulate.

stdConfidence :: Confidence #

The standard parameters used by checkCoverage: certainty = 10^9, tolerance = 0.9. See Confidence for the meaning of the parameters.

checkCoverageWith :: Testable prop => Confidence -> prop -> Property #

Check coverage requirements using a custom confidence level. See stdConfidence.

An example of making the statistical test less stringent in order to improve performance:

quickCheck (checkCoverageWith stdConfidence{certainty = 10^6} prop_foo)

checkCoverage :: Testable prop => prop -> Property #

Check that all coverage requirements defined by cover and coverTable are met, using a statistically sound test, and fail if they are not met.

Ordinarily, a failed coverage check does not cause the property to fail. This is because the coverage requirement is not tested in a statistically sound way. If you use cover to express that a certain value must appear 20% of the time, QuickCheck will warn you if the value only appears in 19 out of 100 test cases - but since the coverage varies randomly, you may have just been unlucky, and there may not be any real problem with your test generation.

When you use checkCoverage, QuickCheck uses a statistical test to account for the role of luck in coverage failures. It will run as many tests as needed until it is sure about whether the coverage requirements are met. If a coverage requirement is not met, the property fails.

Example:

quickCheck (checkCoverage prop_foo)

withMaxSuccess :: Testable prop => Int -> prop -> Property #

Configures how many times a property will be tested.

For example,

quickCheck (withMaxSuccess 1000 p)

will test p up to 1000 times.

again :: Testable prop => prop -> Property #

Modifies a property so that it will be tested repeatedly. Opposite of once.

once :: Testable prop => prop -> Property #

Modifies a property so that it only will be tested once. Opposite of again.

expectFailure :: Testable prop => prop -> Property #

Indicates that a property is supposed to fail. QuickCheck will report an error if it does not fail.

verboseShrinking :: Testable prop => prop -> Property #

Prints out the generated testcase every time the property fails, including during shrinking. Only variables quantified over inside the verboseShrinking are printed.

verbose :: Testable prop => prop -> Property #

Prints out the generated testcase every time the property is tested. Only variables quantified over inside the verbose are printed.

whenFail' :: Testable prop => IO () -> prop -> Property #

Performs an IO action every time a property fails. Thus, if shrinking is done, this can be used to keep track of the failures along the way.

whenFail :: Testable prop => IO () -> prop -> Property #

Performs an IO action after the last failure of a property.

printTestCase :: Testable prop => String -> prop -> Property #

Adds the given string to the counterexample if the property fails.

counterexample :: Testable prop => String -> prop -> Property #

Adds the given string to the counterexample if the property fails.

noShrinking :: Testable prop => prop -> Property #

Disables shrinking for a property altogether. Only quantification inside the call to noShrinking is affected.

shrinking #

Arguments

:: Testable prop 
=> (a -> [a])

shrink-like function.

-> a

The original argument

-> (a -> prop) 
-> Property 

Shrinks the argument to a property if it fails. Shrinking is done automatically for most types. This function is only needed when you want to override the default behavior.

mapSize :: Testable prop => (Int -> Int) -> prop -> Property #

Adjust the test case size for a property, by transforming it with the given function.

idempotentIOProperty :: Testable prop => IO prop -> Property #

Do I/O inside a property.

Warning: during shrinking, the I/O may not always be re-executed. Instead, the I/O may be executed once and then its result retained. If this is not acceptable, use ioProperty instead.

ioProperty :: Testable prop => IO prop -> Property #

Do I/O inside a property.

Warning: any random values generated inside of the argument to ioProperty will not currently be shrunk. For best results, generate all random values before calling ioProperty, or use idempotentIOProperty if that is safe.

Note: if your property does no quantification, it will only be tested once. To test it repeatedly, use again.

data Property #

The type of properties.

Instances
Testable Property 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: Property -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> Property) -> Property #

Example Property 
Instance details

Defined in Test.Hspec.Core.Example

Associated Types

type Arg Property :: Type #

Example (a -> Property) 
Instance details

Defined in Test.Hspec.Core.Example

Associated Types

type Arg (a -> Property) :: Type #

Methods

evaluateExample :: (a -> Property) -> Params -> (ActionWith (Arg (a -> Property)) -> IO ()) -> ProgressCallback -> IO Result #

type Arg Property 
Instance details

Defined in Test.Hspec.Core.Example

type Arg Property = ()
type Arg (a -> Property) 
Instance details

Defined in Test.Hspec.Core.Example

type Arg (a -> Property) = a

class Testable prop where #

The class of properties, i.e., types which QuickCheck knows how to test. Typically a property will be a function returning Bool or Property.

If a property does no quantification, i.e. has no parameters and doesn't use forAll, it will only be tested once. This may not be what you want if your property is an IO Bool. You can change this behaviour using the again combinator.

Minimal complete definition

property

Methods

property :: prop -> Property #

Convert the thing to a property.

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> prop) -> Property #

Optional; used internally in order to improve shrinking. Tests a property but also quantifies over an extra value (with a custom shrink and show function). The Testable instance for functions defines propertyForAllShrinkShow in a way that improves shrinking.

Instances
Testable Bool 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: Bool -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> Bool) -> Property #

Testable () 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: () -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> ()) -> Property #

Testable Prop 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: Prop -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> Prop) -> Property #

Testable Result 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: Result -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> Result) -> Property #

Testable Property 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: Property -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> Property) -> Property #

Testable Discard 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: Discard -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> Discard) -> Property #

Testable prop => Testable (Maybe prop) 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: Maybe prop -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> Maybe prop) -> Property #

Testable prop => Testable (Gen prop) 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: Gen prop -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> Gen prop) -> Property #

(Arbitrary a, Show a, Testable prop) => Testable (a -> prop) 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: (a -> prop) -> Property #

propertyForAllShrinkShow :: Gen a0 -> (a0 -> [a0]) -> (a0 -> [String]) -> (a0 -> a -> prop) -> Property #

data Discard #

If a property returns Discard, the current test case is discarded, the same as if a precondition was false.

An example is the definition of ==>:

(==>) :: Testable prop => Bool -> prop -> Property
False ==> _ = property Discard
True  ==> p = property p

Constructors

Discard 
Instances
Testable Discard 
Instance details

Defined in Test.QuickCheck.Property

Methods

property :: Discard -> Property #

propertyForAllShrinkShow :: Gen a -> (a -> [a]) -> (a -> [String]) -> (a -> Discard) -> Property #

data Confidence #

The statistical parameters used by checkCoverage.

Constructors

Confidence 

Fields

  • certainty :: Integer

    How certain checkCoverage must be before the property fails. If the coverage requirement is met, and the certainty parameter is n, then you should get a false positive at most one in n runs of QuickCheck. The default value is 10^9.

    Lower values will speed up checkCoverage at the cost of false positives.

    If you are using checkCoverage as part of a test suite, you should be careful not to set certainty too low. If you want, say, a 1% chance of a false positive during a project's lifetime, then certainty should be set to at least 100 * m * n, where m is the number of uses of cover in the test suite, and n is the number of times you expect the test suite to be run during the project's lifetime. The default value is chosen to be big enough for most projects.

  • tolerance :: Double

    For statistical reasons, checkCoverage will not reject coverage levels that are only slightly below the required levels. If the required level is p then an actual level of tolerance * p will be accepted. The default value is 0.9.

    Lower values will speed up checkCoverage at the cost of not detecting minor coverage violations.

Instances
Show Confidence 
Instance details

Defined in Test.QuickCheck.State

applyFun3 :: Fun (a, b, c) d -> a -> b -> c -> d #

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

applyFun2 :: 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]

applyFun :: 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"

apply :: Fun a b -> a -> b #

Alias to applyFun.

functionMap :: 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.

functionVoid :: (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.

functionShow :: (Show a, Read a) => (a -> c) -> a :-> c #

Provides a Function instance for types with Show and Read.

functionIntegral :: Integral a => (a -> b) -> a :-> b #

Provides a Function instance for types with Integral.

functionRealFrac :: RealFrac a => (a -> b) -> a :-> b #

Provides a Function instance for types with RealFrac.

functionBoundedEnum :: (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']!

pattern Fn :: forall a b. (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"

pattern Fn2 :: forall a b c. (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]

pattern Fn3 :: forall a b c d. (a -> b -> c -> d) -> Fun (a, b, c) d #

A modifier for testing ternary functions.

data a :-> c #

The type of possibly partial concrete functions

Instances
Functor ((:->) a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

fmap :: (a0 -> b) -> (a :-> a0) -> a :-> b #

(<$) :: a0 -> (a :-> b) -> a :-> a0 #

(Show a, Show b) => Show (a :-> b) 
Instance details

Defined in Test.QuickCheck.Function

Methods

showsPrec :: Int -> (a :-> b) -> ShowS #

show :: (a :-> b) -> String #

showList :: [a :-> b] -> ShowS #

(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] #

class 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.

Minimal complete definition

Nothing

Methods

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

Instances
Function Bool 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Bool -> b) -> Bool :-> b #

Function Char 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Char -> b) -> Char :-> b #

Function Double 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Double -> b) -> Double :-> b #

Function Float 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Float -> b) -> Float :-> b #

Function Int 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Int -> b) -> Int :-> b #

Function Int8 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Int8 -> b) -> Int8 :-> b #

Function Int16 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Int16 -> b) -> Int16 :-> b #

Function Int32 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Int32 -> b) -> Int32 :-> b #

Function Int64 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Int64 -> b) -> Int64 :-> b #

Function Integer 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Integer -> b) -> Integer :-> b #

Function Ordering 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Ordering -> b) -> Ordering :-> b #

Function Word 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Word -> b) -> Word :-> b #

Function Word8 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Word8 -> b) -> Word8 :-> b #

Function Word16 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Word16 -> b) -> Word16 :-> b #

Function Word32 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Word32 -> b) -> Word32 :-> b #

Function Word64 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Word64 -> b) -> Word64 :-> b #

Function () 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (() -> b) -> () :-> b #

Function A 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (A -> b) -> A :-> b #

Function B 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (B -> b) -> B :-> b #

Function C 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (C -> b) -> C :-> b #

Function OrdA 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (OrdA -> b) -> OrdA :-> b #

Function OrdB 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (OrdB -> b) -> OrdB :-> b #

Function OrdC 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (OrdC -> b) -> OrdC :-> b #

Function All 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (All -> b) -> All :-> b #

Function Any 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Any -> b) -> Any :-> b #

Function IntSet 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (IntSet -> b) -> IntSet :-> b #

Function Ix2 Source # 
Instance details

Defined in Test.Massiv.Core.Index

Methods

function :: (Ix2 -> b) -> Ix2 :-> b #

Function Ix3 Source # 
Instance details

Defined in Test.Massiv.Core.Index

Methods

function :: (Ix3 -> b) -> Ix3 :-> b #

Function Ix4 Source # 
Instance details

Defined in Test.Massiv.Core.Index

Methods

function :: (Ix4 -> b) -> Ix4 :-> b #

Function Ix5 Source # 
Instance details

Defined in Test.Massiv.Core.Index

Methods

function :: (Ix5 -> b) -> Ix5 :-> b #

Function a => Function [a] 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

Function a => Function (Maybe a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

(Integral a, Function a) => Function (Ratio a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

(RealFloat a, Function a) => Function (Complex a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

HasResolution a => Function (Fixed a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

Function a => Function (Identity a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

Function a => Function (First a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

Function a => Function (Last a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

Function a => Function (Dual a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

Function a => Function (Sum a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

Function a => Function (Product a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

Function a => Function (IntMap a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

Function a => Function (Seq a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

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

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

Defined in Test.QuickCheck.Function

Methods

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

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

Defined in Test.QuickCheck.Function

Methods

function :: (Either a b -> b0) -> Either a b :-> b0 #

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

Defined in Test.QuickCheck.Function

Methods

function :: ((a, b) -> b0) -> (a, b) :-> b0 #

(Ord a, Function a, Function b) => Function (Map a b) 
Instance details

Defined in Test.QuickCheck.Function

Methods

function :: (Map a b -> b0) -> Map a b :-> b0 #

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

Defined in Test.QuickCheck.Function

Methods

function :: ((a, b, c) -> b0) -> (a, b, c) :-> b0 #

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

Defined in Test.QuickCheck.Function

Methods

function :: (Const a b -> b0) -> Const a b :-> b0 #

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

Defined in Test.QuickCheck.Function

Methods

function :: (Alt f a -> b) -> Alt f a :-> b #

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

Defined in Test.QuickCheck.Function

Methods

function :: ((a, b, c, d) -> b0) -> (a, b, c, d) :-> b0 #

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

Defined in Test.QuickCheck.Function

Methods

function :: ((a, b, c, d, e) -> b0) -> (a, b, c, d, e) :-> b0 #

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

Defined in Test.QuickCheck.Function

Methods

function :: ((a, b, c, d, e, f) -> b0) -> (a, b, c, d, e, f) :-> b0 #

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

Defined in Test.QuickCheck.Function

Methods

function :: ((a, b, c, d, e, f, g) -> b0) -> (a, b, c, d, e, f, g) :-> b0 #

data 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) 
Instances
Functor (Fun a) 
Instance details

Defined in Test.QuickCheck.Function

Methods

fmap :: (a0 -> b) -> Fun a a0 -> Fun a b #

(<$) :: a0 -> Fun a b -> Fun a a0 #

(Show a, Show b) => Show (Fun a b) 
Instance details

Defined in Test.QuickCheck.Function

Methods

showsPrec :: Int -> Fun a b -> ShowS #

show :: Fun a b -> String #

showList :: [Fun a b] -> ShowS #

(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] #

newtype Blind a #

Blind x: as x, but x does not have to be in the Show class.

Constructors

Blind 

Fields

Instances
Functor Blind 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Blind a -> Blind b #

(<$) :: a -> Blind b -> Blind a #

Enum a => Enum (Blind a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

succ :: Blind a -> Blind a #

pred :: Blind a -> Blind a #

toEnum :: Int -> Blind a #

fromEnum :: Blind a -> Int #

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

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

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

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

Eq a => Eq (Blind a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(==) :: Blind a -> Blind a -> Bool #

(/=) :: Blind a -> Blind a -> Bool #

Integral a => Integral (Blind a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

quot :: Blind a -> Blind a -> Blind a #

rem :: Blind a -> Blind a -> Blind a #

div :: Blind a -> Blind a -> Blind a #

mod :: Blind a -> Blind a -> Blind a #

quotRem :: Blind a -> Blind a -> (Blind a, Blind a) #

divMod :: Blind a -> Blind a -> (Blind a, Blind a) #

toInteger :: Blind a -> Integer #

Num a => Num (Blind a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(+) :: Blind a -> Blind a -> Blind a #

(-) :: Blind a -> Blind a -> Blind a #

(*) :: Blind a -> Blind a -> Blind a #

negate :: Blind a -> Blind a #

abs :: Blind a -> Blind a #

signum :: Blind a -> Blind a #

fromInteger :: Integer -> Blind a #

Ord a => Ord (Blind a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

compare :: Blind a -> Blind a -> Ordering #

(<) :: Blind a -> Blind a -> Bool #

(<=) :: Blind a -> Blind a -> Bool #

(>) :: Blind a -> Blind a -> Bool #

(>=) :: Blind a -> Blind a -> Bool #

max :: Blind a -> Blind a -> Blind a #

min :: Blind a -> Blind a -> Blind a #

Real a => Real (Blind a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

toRational :: Blind a -> Rational #

Show (Blind a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> Blind a -> ShowS #

show :: Blind a -> String #

showList :: [Blind a] -> ShowS #

Arbitrary a => Arbitrary (Blind a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Blind a) #

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

newtype Fixed a #

Fixed x: as x, but will not be shrunk.

Constructors

Fixed 

Fields

Instances
Functor Fixed 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Fixed a -> Fixed b #

(<$) :: a -> Fixed b -> Fixed a #

Enum a => Enum (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

succ :: Fixed a -> Fixed a #

pred :: Fixed a -> Fixed a #

toEnum :: Int -> Fixed a #

fromEnum :: Fixed a -> Int #

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

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

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

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

Eq a => Eq (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(==) :: Fixed a -> Fixed a -> Bool #

(/=) :: Fixed a -> Fixed a -> Bool #

Integral a => Integral (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

quot :: Fixed a -> Fixed a -> Fixed a #

rem :: Fixed a -> Fixed a -> Fixed a #

div :: Fixed a -> Fixed a -> Fixed a #

mod :: Fixed a -> Fixed a -> Fixed a #

quotRem :: Fixed a -> Fixed a -> (Fixed a, Fixed a) #

divMod :: Fixed a -> Fixed a -> (Fixed a, Fixed a) #

toInteger :: Fixed a -> Integer #

Num a => Num (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(+) :: Fixed a -> Fixed a -> Fixed a #

(-) :: Fixed a -> Fixed a -> Fixed a #

(*) :: Fixed a -> Fixed a -> Fixed a #

negate :: Fixed a -> Fixed a #

abs :: Fixed a -> Fixed a #

signum :: Fixed a -> Fixed a #

fromInteger :: Integer -> Fixed a #

Ord a => Ord (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

compare :: Fixed a -> Fixed a -> Ordering #

(<) :: Fixed a -> Fixed a -> Bool #

(<=) :: Fixed a -> Fixed a -> Bool #

(>) :: Fixed a -> Fixed a -> Bool #

(>=) :: Fixed a -> Fixed a -> Bool #

max :: Fixed a -> Fixed a -> Fixed a #

min :: Fixed a -> Fixed a -> Fixed a #

Read a => Read (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Real a => Real (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

toRational :: Fixed a -> Rational #

Show a => Show (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> Fixed a -> ShowS #

show :: Fixed a -> String #

showList :: [Fixed a] -> ShowS #

Arbitrary a => Arbitrary (Fixed a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Fixed a) #

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

newtype OrderedList a #

Ordered xs: guarantees that xs is ordered.

Constructors

Ordered 

Fields

Instances
Functor OrderedList 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> OrderedList a -> OrderedList b #

(<$) :: a -> OrderedList b -> OrderedList a #

Eq a => Eq (OrderedList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Ord a => Ord (OrderedList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Read a => Read (OrderedList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Show a => Show (OrderedList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

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

Defined in Test.QuickCheck.Modifiers

newtype NonEmptyList a #

NonEmpty xs: guarantees that xs is non-empty.

Constructors

NonEmpty 

Fields

Instances
Functor NonEmptyList 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> NonEmptyList a -> NonEmptyList b #

(<$) :: a -> NonEmptyList b -> NonEmptyList a #

Eq a => Eq (NonEmptyList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Ord a => Ord (NonEmptyList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Read a => Read (NonEmptyList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Show a => Show (NonEmptyList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Arbitrary a => Arbitrary (NonEmptyList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

data InfiniteList a #

InfiniteList xs _: guarantees that xs is an infinite list. When a counterexample is found, only prints the prefix of xs that was used by the program.

Here is a contrived example property:

prop_take_10 :: InfiniteList Char -> Bool
prop_take_10 (InfiniteList xs _) =
  or [ x == 'a' | x <- take 10 xs ]

In the following counterexample, the list must start with "bbbbbbbbbb" but the remaining (infinite) part can contain anything:

>>> quickCheck prop_take_10
*** Failed! Falsified (after 1 test and 14 shrinks):
"bbbbbbbbbb" ++ ...

Constructors

InfiniteList 

Fields

Instances
Show a => Show (InfiniteList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Arbitrary a => Arbitrary (InfiniteList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

newtype SortedList a #

Sorted xs: guarantees that xs is sorted.

Constructors

Sorted 

Fields

Instances
Functor SortedList 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> SortedList a -> SortedList b #

(<$) :: a -> SortedList b -> SortedList a #

Eq a => Eq (SortedList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(==) :: SortedList a -> SortedList a -> Bool #

(/=) :: SortedList a -> SortedList a -> Bool #

Ord a => Ord (SortedList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Read a => Read (SortedList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Show a => Show (SortedList a) 
Instance details

Defined in Test.QuickCheck.Modifiers

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

Defined in Test.QuickCheck.Modifiers

newtype Positive a #

Positive x: guarantees that x > 0.

Constructors

Positive 

Fields

Instances
Functor Positive 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Positive a -> Positive b #

(<$) :: a -> Positive b -> Positive a #

Enum a => Enum (Positive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Eq a => Eq (Positive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(==) :: Positive a -> Positive a -> Bool #

(/=) :: Positive a -> Positive a -> Bool #

Ord a => Ord (Positive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

compare :: Positive a -> Positive a -> Ordering #

(<) :: Positive a -> Positive a -> Bool #

(<=) :: Positive a -> Positive a -> Bool #

(>) :: Positive a -> Positive a -> Bool #

(>=) :: Positive a -> Positive a -> Bool #

max :: Positive a -> Positive a -> Positive a #

min :: Positive a -> Positive a -> Positive a #

Read a => Read (Positive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Show a => Show (Positive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> Positive a -> ShowS #

show :: Positive a -> String #

showList :: [Positive a] -> ShowS #

(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] #

newtype Negative a #

Negative x: guarantees that x < 0.

Constructors

Negative 

Fields

Instances
Functor Negative 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Negative a -> Negative b #

(<$) :: a -> Negative b -> Negative a #

Enum a => Enum (Negative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Eq a => Eq (Negative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(==) :: Negative a -> Negative a -> Bool #

(/=) :: Negative a -> Negative a -> Bool #

Ord a => Ord (Negative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

compare :: Negative a -> Negative a -> Ordering #

(<) :: Negative a -> Negative a -> Bool #

(<=) :: Negative a -> Negative a -> Bool #

(>) :: Negative a -> Negative a -> Bool #

(>=) :: Negative a -> Negative a -> Bool #

max :: Negative a -> Negative a -> Negative a #

min :: Negative a -> Negative a -> Negative a #

Read a => Read (Negative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Show a => Show (Negative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> Negative a -> ShowS #

show :: Negative a -> String #

showList :: [Negative a] -> ShowS #

(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] #

newtype NonZero a #

NonZero x: guarantees that x /= 0.

Constructors

NonZero 

Fields

Instances
Functor NonZero 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> NonZero a -> NonZero b #

(<$) :: a -> NonZero b -> NonZero a #

Enum a => Enum (NonZero a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

succ :: NonZero a -> NonZero a #

pred :: NonZero a -> NonZero a #

toEnum :: Int -> NonZero a #

fromEnum :: NonZero a -> Int #

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

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

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

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

Eq a => Eq (NonZero a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(==) :: NonZero a -> NonZero a -> Bool #

(/=) :: NonZero a -> NonZero a -> Bool #

Ord a => Ord (NonZero a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

compare :: NonZero a -> NonZero a -> Ordering #

(<) :: NonZero a -> NonZero a -> Bool #

(<=) :: NonZero a -> NonZero a -> Bool #

(>) :: NonZero a -> NonZero a -> Bool #

(>=) :: NonZero a -> NonZero a -> Bool #

max :: NonZero a -> NonZero a -> NonZero a #

min :: NonZero a -> NonZero a -> NonZero a #

Read a => Read (NonZero a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Show a => Show (NonZero a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> NonZero a -> ShowS #

show :: NonZero a -> String #

showList :: [NonZero a] -> ShowS #

(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] #

newtype NonNegative a #

NonNegative x: guarantees that x >= 0.

Constructors

NonNegative 

Fields

Instances
Functor NonNegative 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> NonNegative a -> NonNegative b #

(<$) :: a -> NonNegative b -> NonNegative a #

Enum a => Enum (NonNegative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Eq a => Eq (NonNegative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Ord a => Ord (NonNegative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Read a => Read (NonNegative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Show a => Show (NonNegative a) 
Instance details

Defined in Test.QuickCheck.Modifiers

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

Defined in Test.QuickCheck.Modifiers

newtype NonPositive a #

NonPositive x: guarantees that x <= 0.

Constructors

NonPositive 

Fields

Instances
Functor NonPositive 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> NonPositive a -> NonPositive b #

(<$) :: a -> NonPositive b -> NonPositive a #

Enum a => Enum (NonPositive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Eq a => Eq (NonPositive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Ord a => Ord (NonPositive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Read a => Read (NonPositive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Show a => Show (NonPositive a) 
Instance details

Defined in Test.QuickCheck.Modifiers

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

Defined in Test.QuickCheck.Modifiers

newtype Large a #

Large x: by default, QuickCheck generates Ints drawn from a small range. Large Int gives you values drawn from the entire range instead.

Constructors

Large 

Fields

Instances
Functor Large 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Large a -> Large b #

(<$) :: a -> Large b -> Large a #

Enum a => Enum (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

succ :: Large a -> Large a #

pred :: Large a -> Large a #

toEnum :: Int -> Large a #

fromEnum :: Large a -> Int #

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

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

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

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

Eq a => Eq (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(==) :: Large a -> Large a -> Bool #

(/=) :: Large a -> Large a -> Bool #

Integral a => Integral (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

quot :: Large a -> Large a -> Large a #

rem :: Large a -> Large a -> Large a #

div :: Large a -> Large a -> Large a #

mod :: Large a -> Large a -> Large a #

quotRem :: Large a -> Large a -> (Large a, Large a) #

divMod :: Large a -> Large a -> (Large a, Large a) #

toInteger :: Large a -> Integer #

Num a => Num (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(+) :: Large a -> Large a -> Large a #

(-) :: Large a -> Large a -> Large a #

(*) :: Large a -> Large a -> Large a #

negate :: Large a -> Large a #

abs :: Large a -> Large a #

signum :: Large a -> Large a #

fromInteger :: Integer -> Large a #

Ord a => Ord (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

compare :: Large a -> Large a -> Ordering #

(<) :: Large a -> Large a -> Bool #

(<=) :: Large a -> Large a -> Bool #

(>) :: Large a -> Large a -> Bool #

(>=) :: Large a -> Large a -> Bool #

max :: Large a -> Large a -> Large a #

min :: Large a -> Large a -> Large a #

Read a => Read (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Real a => Real (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

toRational :: Large a -> Rational #

Show a => Show (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> Large a -> ShowS #

show :: Large a -> String #

showList :: [Large a] -> ShowS #

Ix a => Ix (Large a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

range :: (Large a, Large a) -> [Large a] #

index :: (Large a, Large a) -> Large a -> Int #

unsafeIndex :: (Large a, Large a) -> Large a -> Int

inRange :: (Large a, Large a) -> Large a -> Bool #

rangeSize :: (Large a, Large a) -> Int #

unsafeRangeSize :: (Large a, Large a) -> Int

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

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Large a) #

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

newtype Small a #

Small x: generates values of x drawn from a small range. The opposite of Large.

Constructors

Small 

Fields

Instances
Functor Small 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Small a -> Small b #

(<$) :: a -> Small b -> Small a #

Enum a => Enum (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

succ :: Small a -> Small a #

pred :: Small a -> Small a #

toEnum :: Int -> Small a #

fromEnum :: Small a -> Int #

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

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

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

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

Eq a => Eq (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(==) :: Small a -> Small a -> Bool #

(/=) :: Small a -> Small a -> Bool #

Integral a => Integral (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

quot :: Small a -> Small a -> Small a #

rem :: Small a -> Small a -> Small a #

div :: Small a -> Small a -> Small a #

mod :: Small a -> Small a -> Small a #

quotRem :: Small a -> Small a -> (Small a, Small a) #

divMod :: Small a -> Small a -> (Small a, Small a) #

toInteger :: Small a -> Integer #

Num a => Num (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(+) :: Small a -> Small a -> Small a #

(-) :: Small a -> Small a -> Small a #

(*) :: Small a -> Small a -> Small a #

negate :: Small a -> Small a #

abs :: Small a -> Small a #

signum :: Small a -> Small a #

fromInteger :: Integer -> Small a #

Ord a => Ord (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

compare :: Small a -> Small a -> Ordering #

(<) :: Small a -> Small a -> Bool #

(<=) :: Small a -> Small a -> Bool #

(>) :: Small a -> Small a -> Bool #

(>=) :: Small a -> Small a -> Bool #

max :: Small a -> Small a -> Small a #

min :: Small a -> Small a -> Small a #

Read a => Read (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Real a => Real (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

toRational :: Small a -> Rational #

Show a => Show (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> Small a -> ShowS #

show :: Small a -> String #

showList :: [Small a] -> ShowS #

Ix a => Ix (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

range :: (Small a, Small a) -> [Small a] #

index :: (Small a, Small a) -> Small a -> Int #

unsafeIndex :: (Small a, Small a) -> Small a -> Int

inRange :: (Small a, Small a) -> Small a -> Bool #

rangeSize :: (Small a, Small a) -> Int #

unsafeRangeSize :: (Small a, Small a) -> Int

Integral a => Arbitrary (Small a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Small a) #

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

newtype Shrink2 a #

Shrink2 x: allows 2 shrinking steps at the same time when shrinking x

Constructors

Shrink2 

Fields

Instances
Functor Shrink2 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Shrink2 a -> Shrink2 b #

(<$) :: a -> Shrink2 b -> Shrink2 a #

Enum a => Enum (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

succ :: Shrink2 a -> Shrink2 a #

pred :: Shrink2 a -> Shrink2 a #

toEnum :: Int -> Shrink2 a #

fromEnum :: Shrink2 a -> Int #

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

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

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

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

Eq a => Eq (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(==) :: Shrink2 a -> Shrink2 a -> Bool #

(/=) :: Shrink2 a -> Shrink2 a -> Bool #

Integral a => Integral (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

quot :: Shrink2 a -> Shrink2 a -> Shrink2 a #

rem :: Shrink2 a -> Shrink2 a -> Shrink2 a #

div :: Shrink2 a -> Shrink2 a -> Shrink2 a #

mod :: Shrink2 a -> Shrink2 a -> Shrink2 a #

quotRem :: Shrink2 a -> Shrink2 a -> (Shrink2 a, Shrink2 a) #

divMod :: Shrink2 a -> Shrink2 a -> (Shrink2 a, Shrink2 a) #

toInteger :: Shrink2 a -> Integer #

Num a => Num (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

(+) :: Shrink2 a -> Shrink2 a -> Shrink2 a #

(-) :: Shrink2 a -> Shrink2 a -> Shrink2 a #

(*) :: Shrink2 a -> Shrink2 a -> Shrink2 a #

negate :: Shrink2 a -> Shrink2 a #

abs :: Shrink2 a -> Shrink2 a #

signum :: Shrink2 a -> Shrink2 a #

fromInteger :: Integer -> Shrink2 a #

Ord a => Ord (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

compare :: Shrink2 a -> Shrink2 a -> Ordering #

(<) :: Shrink2 a -> Shrink2 a -> Bool #

(<=) :: Shrink2 a -> Shrink2 a -> Bool #

(>) :: Shrink2 a -> Shrink2 a -> Bool #

(>=) :: Shrink2 a -> Shrink2 a -> Bool #

max :: Shrink2 a -> Shrink2 a -> Shrink2 a #

min :: Shrink2 a -> Shrink2 a -> Shrink2 a #

Read a => Read (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Real a => Real (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

toRational :: Shrink2 a -> Rational #

Show a => Show (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> Shrink2 a -> ShowS #

show :: Shrink2 a -> String #

showList :: [Shrink2 a] -> ShowS #

Arbitrary a => Arbitrary (Shrink2 a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Shrink2 a) #

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

data Smart a #

Smart _ x: tries a different order when shrinking.

Constructors

Smart Int a 
Instances
Functor Smart 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Smart a -> Smart b #

(<$) :: a -> Smart b -> Smart a #

Show a => Show (Smart a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> Smart a -> ShowS #

show :: Smart a -> String #

showList :: [Smart a] -> ShowS #

Arbitrary a => Arbitrary (Smart a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

arbitrary :: Gen (Smart a) #

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

data Shrinking s a #

Shrinking _ x: allows for maintaining a state during shrinking.

Constructors

Shrinking s a 
Instances
Functor (Shrinking s) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

fmap :: (a -> b) -> Shrinking s a -> Shrinking s b #

(<$) :: a -> Shrinking s b -> Shrinking s a #

Show a => Show (Shrinking s a) 
Instance details

Defined in Test.QuickCheck.Modifiers

Methods

showsPrec :: Int -> Shrinking s a -> ShowS #

show :: Shrinking s a -> String #

showList :: [Shrinking s a] -> ShowS #

(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] #

class ShrinkState s a where #

Methods

shrinkInit :: a -> s #

shrinkState :: a -> s -> [(a, s)] #

infiniteList :: Arbitrary a => Gen [a] #

Generates an infinite list.

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

Generates an ordered list.

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

Generates a list of a given length.

coarbitraryEnum :: Enum a => a -> Gen b -> Gen b #

A coarbitrary implementation for enums.

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

coarbitrary helper for lazy people :-).

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

A coarbitrary implementation for real numbers.

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

A coarbitrary implementation for integral numbers.

(><) :: (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.

genericCoarbitrary :: (Generic a, GCoArbitrary (Rep a)) => a -> Gen b -> Gen b #

Generic CoArbitrary implementation.

shrinkDecimal :: RealFrac a => a -> [a] #

Shrink a real number, preferring numbers with shorter decimal representations. See also shrinkRealFrac.

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

Shrink a fraction, preferring numbers with smaller numerators or denominators. See also shrinkDecimal.

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

Shrink an integral number.

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

Non-overloaded version of shrinkMap.

shrinkMap :: Arbitrary a => (a -> b) -> (b -> a) -> b -> [b] #

Map a shrink function to another domain. This is handy if your data type has special invariants, but is almost isomorphic to some other type.

shrinkOrderedList :: (Ord a, Arbitrary a) => [a] -> [[a]]
shrinkOrderedList = shrinkMap sort id

shrinkSet :: (Ord a, Arbitrary a) => Set a -> Set [a]
shrinkSet = shrinkMap fromList toList

shrinkNothing :: a -> [a] #

Returns no shrinking alternatives.

arbitraryPrintableChar :: Gen Char #

Generates a printable Unicode character.

arbitraryASCIIChar :: Gen Char #

Generates a random ASCII character (0-127).

arbitraryUnicodeChar :: Gen Char #

Generates any Unicode character (but not a surrogate)

arbitrarySizedBoundedIntegral :: (Bounded a, Integral a) => Gen a #

Generates an integral number from a bounded domain. The number is chosen from the entire range of the type, but small numbers are generated more often than big numbers. Inspired by demands from Phil Wadler.

arbitraryBoundedEnum :: (Bounded a, Enum a) => Gen a #

Generates an element of a bounded enumeration.

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.

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

Generates an integral number. The number is chosen uniformly from the entire range of the type. You may want to use arbitrarySizedBoundedIntegral instead.

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.

arbitrarySizedNatural :: Integral a => Gen a #

Generates a natural number. The number's maximum value depends on the size parameter.

arbitrarySizedIntegral :: Integral a => Gen a #

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

applyArbitrary4 :: (Arbitrary a, Arbitrary b, Arbitrary c, Arbitrary d) => (a -> b -> c -> d -> r) -> Gen r #

Apply a function of arity 4 to random arguments.

applyArbitrary3 :: (Arbitrary a, Arbitrary b, Arbitrary c) => (a -> b -> c -> r) -> Gen r #

Apply a ternary function to random arguments.

applyArbitrary2 :: (Arbitrary a, Arbitrary b) => (a -> b -> r) -> Gen r #

Apply a binary function to random arguments.

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

Shrink a list of values given a shrinking function for individual values.

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

All immediate subterms of a term.

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

Recursively shrink all immediate subterms.

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.

shrink2 :: (Arbitrary2 f, Arbitrary a, Arbitrary b) => f a b -> [f a b] #

arbitrary2 :: (Arbitrary2 f, Arbitrary a, Arbitrary b) => Gen (f a b) #

shrink1 :: (Arbitrary1 f, Arbitrary a) => f a -> [f a] #

arbitrary1 :: (Arbitrary1 f, Arbitrary a) => Gen (f a) #

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
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