Test.QuickCheck.Arbitrary

class Arbitrary t  where

The Arbitrary class represents those types whose values can be randomly-generated.

arbitrary uses the Gen monad to express a random generator for the type t. Combinators in the Test.QuickCheck.Gen module can be used to construct random generators.

Members

• arbitrary :: Gen t

Instances

• Arbitrary Boolean
• Arbitrary Number
• Arbitrary Int
• Arbitrary String
• Arbitrary Char
• Arbitrary Unit
• Arbitrary Ordering
• (Arbitrary a) => Arbitrary (Array a)
• (Coarbitrary a, Arbitrary b) => Arbitrary (a -> b)
• (Arbitrary a, Arbitrary b) => Arbitrary (Tuple a b)
• (Arbitrary a) => Arbitrary (Maybe a)
• (Arbitrary a, Arbitrary b) => Arbitrary (Either a b)
• (Arbitrary a) => Arbitrary (List a)
• (Arbitrary a) => Arbitrary (Identity a)
• (Arbitrary a) => Arbitrary (Lazy a)
• (Arbitrary (f a), Arbitrary a) => Arbitrary (NonEmpty f a)
• (Arbitrary a) => Arbitrary (NonEmptyList a)

class Coarbitrary t  where

The Coarbitrary class represents types which appear on the left of an Arbitrary function arrow.

To construct an Arbitrary instance for the type a -> b, we need to use the input of type a to perturb a random generator for b. This is the role of the coarbitrary function.

Coarbitrary instances can be written using the perturbGen function.

Members

• coarbitrary :: forall r. t -> Gen r -> Gen r

Instances

• Coarbitrary Boolean
• Coarbitrary Number
• Coarbitrary Int
• Coarbitrary String
• Coarbitrary Char
• Coarbitrary Unit
• Coarbitrary Ordering
• (Coarbitrary a) => Coarbitrary (Array a)
• (Arbitrary a, Coarbitrary b) => Coarbitrary (a -> b)
• (Coarbitrary a, Coarbitrary b) => Coarbitrary (Tuple a b)
• (Coarbitrary a) => Coarbitrary (Maybe a)
• (Coarbitrary a, Coarbitrary b) => Coarbitrary (Either a b)
• (Coarbitrary a) => Coarbitrary (List a)
• (Coarbitrary a) => Coarbitrary (Identity a)
• (Coarbitrary a) => Coarbitrary (Lazy a)
• (Coarbitrary (f a), Coarbitrary a) => Coarbitrary (NonEmpty f a)
• (Coarbitrary a) => Coarbitrary (NonEmptyList a)