QuickCheck-2.9.2: Automatic testing of Haskell programs

Safe Haskell | Trustworthy
Language | Haskell98

Test.QuickCheck.Modifiers

Contents

- Type-level modifiers for changing generator behavior

Description

Modifiers for test data.

These types do things such as restricting the kind of test data that can be generated. They can be pattern-matched on in properties as a stylistic alternative to using explicit quantification.

Examples:

    -- Functions cannot be shown (but see Test.QuickCheck.Function)
    prop_TakeDropWhile (Blind p) (xs :: [A]) =
      takeWhile p xs ++ dropWhile p xs == xs

    prop_TakeDrop (NonNegative n) (xs :: [A]) =
      take n xs ++ drop n xs == xs

    -- cycle does not work for empty lists
    prop_Cycle (NonNegative n) (NonEmpty (xs :: [A])) =
      take n (cycle xs) == take n (xs ++ cycle xs)

    -- Instead of forAll orderedList
    prop_Sort (Ordered (xs :: [OrdA])) =
      sort xs == xs

Synopsis

- newtype Blind a = Blind {
  - getBlind :: a
  }
- newtype Fixed a = Fixed {
  - getFixed :: a
  }
- newtype OrderedList a = Ordered {
  - getOrdered :: [a]
  }
- newtype NonEmptyList a = NonEmpty {
  - getNonEmpty :: [a]
  }
- newtype Positive a = Positive {
  - getPositive :: a
  }
- newtype NonZero a = NonZero {
  - getNonZero :: a
  }
- newtype NonNegative a = NonNegative {
  - getNonNegative :: a
  }
- newtype Large a = Large {
  - getLarge :: a
  }
- newtype Small a = Small {
  - getSmall :: a
  }
- data Smart a = Smart Int a
- newtype Shrink2 a = Shrink2 {
  - getShrink2 :: a
  }
- data Shrinking s a = Shrinking s a
- class ShrinkState s a where

## Type-level modifiers for changing generator behavior

newtype Blind a #

`Blind x`: as x, but x does not have to be in the `Show` class.

Constructors

Blind |
Fields getBlind :: a

Instances

Functor Blind # |
Methods fmap :: (a -> b) -> Blind a -> Blind b # (<$) :: a -> Blind b -> Blind a #
Enum a => Enum (Blind a) # |
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) # |
Methods (==) :: Blind a -> Blind a -> Bool # (/=) :: Blind a -> Blind a -> Bool #
Integral a => Integral (Blind a) # |
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) # |
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) # |
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) # |
Methods toRational :: Blind a -> Rational #
Show (Blind a) # |
Methods showsPrec :: Int -> Blind a -> ShowS # show :: Blind a -> String # showList :: [Blind a] -> ShowS #
Arbitrary a => Arbitrary (Blind a) # |
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 getFixed :: a

Instances

Functor Fixed # |
Methods fmap :: (a -> b) -> Fixed a -> Fixed b # (<$) :: a -> Fixed b -> Fixed a #
Enum a => Enum (Fixed a) # |
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) # |
Methods (==) :: Fixed a -> Fixed a -> Bool # (/=) :: Fixed a -> Fixed a -> Bool #
Integral a => Integral (Fixed a) # |
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) # |
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) # |
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) # |
Methods readsPrec :: Int -> ReadS (Fixed a) # readList :: ReadS [Fixed a] # readPrec :: ReadPrec (Fixed a) # readListPrec :: ReadPrec [Fixed a] #
Real a => Real (Fixed a) # |
Methods toRational :: Fixed a -> Rational #
Show a => Show (Fixed a) # |
Methods showsPrec :: Int -> Fixed a -> ShowS # show :: Fixed a -> String # showList :: [Fixed a] -> ShowS #
Arbitrary a => Arbitrary (Fixed a) # |
Methods arbitrary :: Gen (Fixed a) # shrink :: Fixed a -> [Fixed a] #

newtype OrderedList a #

`Ordered xs`: guarantees that xs is ordered.

Constructors

Ordered |
Fields getOrdered :: [a]

Instances

Functor OrderedList # |
Methods fmap :: (a -> b) -> OrderedList a -> OrderedList b # (<$) :: a -> OrderedList b -> OrderedList a #
Eq a => Eq (OrderedList a) # |
Methods (==) :: OrderedList a -> OrderedList a -> Bool # (/=) :: OrderedList a -> OrderedList a -> Bool #
Ord a => Ord (OrderedList a) # |
Methods compare :: OrderedList a -> OrderedList a -> Ordering # (<) :: OrderedList a -> OrderedList a -> Bool # (<=) :: OrderedList a -> OrderedList a -> Bool # (>) :: OrderedList a -> OrderedList a -> Bool # (>=) :: OrderedList a -> OrderedList a -> Bool # max :: OrderedList a -> OrderedList a -> OrderedList a # min :: OrderedList a -> OrderedList a -> OrderedList a #
Read a => Read (OrderedList a) # |
Methods readsPrec :: Int -> ReadS (OrderedList a) # readList :: ReadS [OrderedList a] # readPrec :: ReadPrec (OrderedList a) # readListPrec :: ReadPrec [OrderedList a] #
Show a => Show (OrderedList a) # |
Methods showsPrec :: Int -> OrderedList a -> ShowS # show :: OrderedList a -> String # showList :: [OrderedList a] -> ShowS #
(Ord a, Arbitrary a) => Arbitrary (OrderedList a) # |
Methods arbitrary :: Gen (OrderedList a) # shrink :: OrderedList a -> [OrderedList a] #

newtype NonEmptyList a #

`NonEmpty xs`: guarantees that xs is non-empty.

Constructors

NonEmpty |
Fields getNonEmpty :: [a]

Instances

Functor NonEmptyList # |
Methods fmap :: (a -> b) -> NonEmptyList a -> NonEmptyList b # (<$) :: a -> NonEmptyList b -> NonEmptyList a #
Eq a => Eq (NonEmptyList a) # |
Methods (==) :: NonEmptyList a -> NonEmptyList a -> Bool # (/=) :: NonEmptyList a -> NonEmptyList a -> Bool #
Ord a => Ord (NonEmptyList a) # |
Methods compare :: NonEmptyList a -> NonEmptyList a -> Ordering # (<) :: NonEmptyList a -> NonEmptyList a -> Bool # (<=) :: NonEmptyList a -> NonEmptyList a -> Bool # (>) :: NonEmptyList a -> NonEmptyList a -> Bool # (>=) :: NonEmptyList a -> NonEmptyList a -> Bool # max :: NonEmptyList a -> NonEmptyList a -> NonEmptyList a # min :: NonEmptyList a -> NonEmptyList a -> NonEmptyList a #
Read a => Read (NonEmptyList a) # |
Methods readsPrec :: Int -> ReadS (NonEmptyList a) # readList :: ReadS [NonEmptyList a] # readPrec :: ReadPrec (NonEmptyList a) # readListPrec :: ReadPrec [NonEmptyList a] #
Show a => Show (NonEmptyList a) # |
Methods showsPrec :: Int -> NonEmptyList a -> ShowS # show :: NonEmptyList a -> String # showList :: [NonEmptyList a] -> ShowS #
Arbitrary a => Arbitrary (NonEmptyList a) # |
Methods arbitrary :: Gen (NonEmptyList a) # shrink :: NonEmptyList a -> [NonEmptyList a] #

newtype Positive a #

`Positive x`: guarantees that `x > 0`.

Constructors

Positive |
Fields getPositive :: a

Instances

Functor Positive # |
Methods fmap :: (a -> b) -> Positive a -> Positive b # (<$) :: a -> Positive b -> Positive a #
Enum a => Enum (Positive a) # |
Methods succ :: Positive a -> Positive a # pred :: Positive a -> Positive a # toEnum :: Int -> Positive a # fromEnum :: Positive a -> Int # enumFrom :: Positive a -> [Positive a] # enumFromThen :: Positive a -> Positive a -> [Positive a] # enumFromTo :: Positive a -> Positive a -> [Positive a] # enumFromThenTo :: Positive a -> Positive a -> Positive a -> [Positive a] #
Eq a => Eq (Positive a) # |
Methods (==) :: Positive a -> Positive a -> Bool # (/=) :: Positive a -> Positive a -> Bool #
Ord a => Ord (Positive a) # |
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) # |
Methods readsPrec :: Int -> ReadS (Positive a) # readList :: ReadS [Positive a] # readPrec :: ReadPrec (Positive a) # readListPrec :: ReadPrec [Positive a] #
Show a => Show (Positive a) # |
Methods showsPrec :: Int -> Positive a -> ShowS # show :: Positive a -> String # showList :: [Positive a] -> ShowS #
(Num a, Ord a, Arbitrary a) => Arbitrary (Positive a) # |
Methods arbitrary :: Gen (Positive a) # shrink :: Positive a -> [Positive a] #

newtype NonZero a #

`NonZero x`: guarantees that `x /= 0`.

Constructors

NonZero |
Fields getNonZero :: a

Instances

Functor NonZero # |
Methods fmap :: (a -> b) -> NonZero a -> NonZero b # (<$) :: a -> NonZero b -> NonZero a #
Enum a => Enum (NonZero a) # |
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) # |
Methods (==) :: NonZero a -> NonZero a -> Bool # (/=) :: NonZero a -> NonZero a -> Bool #
Ord a => Ord (NonZero a) # |
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) # |
Methods readsPrec :: Int -> ReadS (NonZero a) # readList :: ReadS [NonZero a] # readPrec :: ReadPrec (NonZero a) # readListPrec :: ReadPrec [NonZero a] #
Show a => Show (NonZero a) # |
Methods showsPrec :: Int -> NonZero a -> ShowS # show :: NonZero a -> String # showList :: [NonZero a] -> ShowS #
(Num a, Eq a, Arbitrary a) => Arbitrary (NonZero a) # |
Methods arbitrary :: Gen (NonZero a) # shrink :: NonZero a -> [NonZero a] #

newtype NonNegative a #

`NonNegative x`: guarantees that `x >= 0`.

Constructors

NonNegative |
Fields getNonNegative :: a

Instances

Functor NonNegative # |
Methods fmap :: (a -> b) -> NonNegative a -> NonNegative b # (<$) :: a -> NonNegative b -> NonNegative a #
Enum a => Enum (NonNegative a) # |
Methods succ :: NonNegative a -> NonNegative a # pred :: NonNegative a -> NonNegative a # toEnum :: Int -> NonNegative a # fromEnum :: NonNegative a -> Int # enumFrom :: NonNegative a -> [NonNegative a] # enumFromThen :: NonNegative a -> NonNegative a -> [NonNegative a] # enumFromTo :: NonNegative a -> NonNegative a -> [NonNegative a] # enumFromThenTo :: NonNegative a -> NonNegative a -> NonNegative a -> [NonNegative a] #
Eq a => Eq (NonNegative a) # |
Methods (==) :: NonNegative a -> NonNegative a -> Bool # (/=) :: NonNegative a -> NonNegative a -> Bool #
Ord a => Ord (NonNegative a) # |
Methods compare :: NonNegative a -> NonNegative a -> Ordering # (<) :: NonNegative a -> NonNegative a -> Bool # (<=) :: NonNegative a -> NonNegative a -> Bool # (>) :: NonNegative a -> NonNegative a -> Bool # (>=) :: NonNegative a -> NonNegative a -> Bool # max :: NonNegative a -> NonNegative a -> NonNegative a # min :: NonNegative a -> NonNegative a -> NonNegative a #
Read a => Read (NonNegative a) # |
Methods readsPrec :: Int -> ReadS (NonNegative a) # readList :: ReadS [NonNegative a] # readPrec :: ReadPrec (NonNegative a) # readListPrec :: ReadPrec [NonNegative a] #
Show a => Show (NonNegative a) # |
Methods showsPrec :: Int -> NonNegative a -> ShowS # show :: NonNegative a -> String # showList :: [NonNegative a] -> ShowS #
(Num a, Ord a, Arbitrary a) => Arbitrary (NonNegative a) # |
Methods arbitrary :: Gen (NonNegative a) # shrink :: NonNegative a -> [NonNegative a] #

newtype Large a #

`Large x`: by default, QuickCheck generates `Int`s drawn from a small range. `Large Int` gives you values drawn from the entire range instead.

Constructors

Large |
Fields getLarge :: a

Instances

Functor Large # |
Methods fmap :: (a -> b) -> Large a -> Large b # (<$) :: a -> Large b -> Large a #
Enum a => Enum (Large a) # |
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) # |
Methods (==) :: Large a -> Large a -> Bool # (/=) :: Large a -> Large a -> Bool #
Integral a => Integral (Large a) # |
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) # |
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) # |
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) # |
Methods readsPrec :: Int -> ReadS (Large a) # readList :: ReadS [Large a] # readPrec :: ReadPrec (Large a) # readListPrec :: ReadPrec [Large a] #
Real a => Real (Large a) # |
Methods toRational :: Large a -> Rational #
Show a => Show (Large a) # |
Methods showsPrec :: Int -> Large a -> ShowS # show :: Large a -> String # showList :: [Large a] -> ShowS #
(Integral a, Bounded a) => Arbitrary (Large a) # |
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 getSmall :: a

Instances

Functor Small # |
Methods fmap :: (a -> b) -> Small a -> Small b # (<$) :: a -> Small b -> Small a #
Enum a => Enum (Small a) # |
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) # |
Methods (==) :: Small a -> Small a -> Bool # (/=) :: Small a -> Small a -> Bool #
Integral a => Integral (Small a) # |
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) # |
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) # |
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) # |
Methods readsPrec :: Int -> ReadS (Small a) # readList :: ReadS [Small a] # readPrec :: ReadPrec (Small a) # readListPrec :: ReadPrec [Small a] #
Real a => Real (Small a) # |
Methods toRational :: Small a -> Rational #
Show a => Show (Small a) # |
Methods showsPrec :: Int -> Small a -> ShowS # show :: Small a -> String # showList :: [Small a] -> ShowS #
Integral a => Arbitrary (Small a) # |
Methods arbitrary :: Gen (Small a) # shrink :: Small a -> [Small a] #

data Smart a #

`Smart _ x`: tries a different order when shrinking.

Constructors

Smart Int a |

Instances

Functor Smart # |
Methods fmap :: (a -> b) -> Smart a -> Smart b # (<$) :: a -> Smart b -> Smart a #
Show a => Show (Smart a) # |
Methods showsPrec :: Int -> Smart a -> ShowS # show :: Smart a -> String # showList :: [Smart a] -> ShowS #
Arbitrary a => Arbitrary (Smart a) # |
Methods arbitrary :: Gen (Smart a) # shrink :: Smart a -> [Smart a] #

newtype Shrink2 a #

`Shrink2 x`: allows 2 shrinking steps at the same time when shrinking x

Constructors

Shrink2 |
Fields getShrink2 :: a

Instances

Functor Shrink2 # |
Methods fmap :: (a -> b) -> Shrink2 a -> Shrink2 b # (<$) :: a -> Shrink2 b -> Shrink2 a #
Enum a => Enum (Shrink2 a) # |
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) # |
Methods (==) :: Shrink2 a -> Shrink2 a -> Bool # (/=) :: Shrink2 a -> Shrink2 a -> Bool #
Integral a => Integral (Shrink2 a) # |
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) # |
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) # |
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) # |
Methods readsPrec :: Int -> ReadS (Shrink2 a) # readList :: ReadS [Shrink2 a] # readPrec :: ReadPrec (Shrink2 a) # readListPrec :: ReadPrec [Shrink2 a] #
Real a => Real (Shrink2 a) # |
Methods toRational :: Shrink2 a -> Rational #
Show a => Show (Shrink2 a) # |
Methods showsPrec :: Int -> Shrink2 a -> ShowS # show :: Shrink2 a -> String # showList :: [Shrink2 a] -> ShowS #
Arbitrary a => Arbitrary (Shrink2 a) # |
Methods arbitrary :: Gen (Shrink2 a) # shrink :: Shrink2 a -> [Shrink2 a] #

data Shrinking s a #

`Shrinking _ x`: allows for maintaining a state during shrinking.

Constructors

Shrinking s a |

Instances

Functor (Shrinking s) # |
Methods fmap :: (a -> b) -> Shrinking s a -> Shrinking s b # (<$) :: a -> Shrinking s b -> Shrinking s a #
Show a => Show (Shrinking s a) # |
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) # |
Methods arbitrary :: Gen (Shrinking s a) # shrink :: Shrinking s a -> [Shrinking s a] #

class ShrinkState s a where #

Minimal complete definition

shrinkInit, shrinkState

Methods

shrinkInit :: a -> s #

shrinkState :: a -> s -> [(a, s)] #