Module Test.Prop

Exported Functions

returns :: (Eq a, Show a) => IO a -> a -> PropIO   

The property returns a x is satisfied if the execution of the I/O action a returns the value x.

Further infos:

• defined as non-associative infix operator with precedence 1

sameReturns :: (Eq a, Show a) => IO a -> IO a -> PropIO   

The property sameReturns a1 a2 is satisfied if the execution of the I/O actions a1 and a2 return identical values.

Further infos:

• defined as non-associative infix operator with precedence 1

toError :: a -> PropIO   

The property toError a is satisfied if the evaluation of the argument to normal form yields an exception.

toIOError :: IO a -> PropIO   

The property toIOError a is satisfied if the execution of the I/O action a causes an exception.

(-=-) :: (Eq a, Show a) => a -> a -> Prop   

The property x -=- y is satisfied if x and y have deterministic values that are equal.

Further infos:

• defined as non-associative infix operator with precedence 1

(<~>) :: (Eq a, Show a) => a -> a -> Prop   

The property x <~> y is satisfied if the sets of the values of x and y are equal.

Further infos:

• defined as non-associative infix operator with precedence 1

(~>) :: (Eq a, Show a) => a -> a -> Prop   

The property x ~> y is satisfied if x evaluates to every value of y. Thus, the set of values of y must be a subset of the set of values of x.

Further infos:

• defined as non-associative infix operator with precedence 1

(<~) :: (Eq a, Show a) => a -> a -> Prop   

The property x <~ y is satisfied if y evaluates to every value of x. Thus, the set of values of x must be a subset of the set of values of y.

Further infos:

• defined as non-associative infix operator with precedence 1

(<~~>) :: (Eq a, Show a) => a -> a -> Prop   

The property x <~~> y is satisfied if the multisets of the values of x and y are equal.

Further infos:

• defined as non-associative infix operator with precedence 1

(==>) :: Bool -> Prop -> Prop   

A conditional property is tested if the condition evaluates to True.

Further infos:

• defined as right-associative infix operator with precedence 0

solutionOf :: Data a => (a -> Bool) -> a   

solutionOf p returns (non-deterministically) a solution of predicate p. This operation is useful to test solutions of predicates.

is :: Show a => a -> (a -> Bool) -> Prop   

The property is x p is satisfied if x has a deterministic value which satisfies p.

Further infos:

• defined as non-associative infix operator with precedence 1

isAlways :: Show a => a -> (a -> Bool) -> Prop   

The property isAlways x p is satisfied if all values of x satisfy p.

Further infos:

• defined as non-associative infix operator with precedence 1

isEventually :: Show a => a -> (a -> Bool) -> Prop   

The property isEventually x p is satisfied if some value of x satisfies p.

Further infos:

• defined as non-associative infix operator with precedence 1

uniquely :: Bool -> Prop   

The property uniquely x is satisfied if x has a deterministic value which is true.

always :: Bool -> Prop   

The property always x is satisfied if all values of x are true.

eventually :: Bool -> Prop   

The property eventually x is satisfied if some value of x is true.

failing :: Show a => a -> Prop   

The property failing x is satisfied if x has no value.

successful :: Show a => a -> Prop   

The property successful x is satisfied if x has at least one value.

deterministic :: Show a => a -> Prop   

The property deterministic x is satisfied if x has exactly one value.

(#) :: (Eq a, Show a) => a -> Int -> Prop   

The property x # n is satisfied if x has n values.

Further infos:

• defined as non-associative infix operator with precedence 1

(#<) :: (Eq a, Show a) => a -> Int -> Prop   

The property x #< n is satisfied if x has less than n values.

Further infos:

• defined as non-associative infix operator with precedence 1

(#>) :: (Eq a, Show a) => a -> Int -> Prop   

The property x #> n is satisfied if x has more than n values.

Further infos:

• defined as non-associative infix operator with precedence 1

for :: Show a => a -> (a -> Prop) -> Prop   

The property for x p is satisfied if all values y of x satisfy property p y.

forAll :: Show a => [a] -> (a -> Prop) -> Prop   

The property forAll xs p is satisfied if all values x of the list xs satisfy property p x.

(<=>) :: a -> a -> Prop   

The property f <=> g is satisfied if f and g are equivalent operations, i.e., they can be replaced in any context without changing the computed results.

Further infos:

• defined as non-associative infix operator with precedence 1

label :: String -> Prop -> Prop   

Assign a label to a property. All labeled tests are counted and shown at the end.

classify :: Bool -> String -> Prop -> Prop   

Assign a label to a property if the first argument is True. All labeled tests are counted and shown at the end. Hence, this combinator can be used to classify tests:

multIsComm x y = classify (x<0 || y<0) "Negative" $ x*y -=- y*x

trivial :: Bool -> Prop -> Prop   

Assign the label "trivial" to a property if the first argument is True. All labeled tests are counted and shown at the end.

Further infos:

• defined as non-associative infix operator with precedence 1

collect :: Show a => a -> Prop -> Prop   

Assign a label showing the given argument to a property. All labeled tests are counted and shown at the end.

collectAs :: Show a => String -> a -> Prop -> Prop   

Assign a label showing a given name and the given argument to a property. All labeled tests are counted and shown at the end.

valuesOf :: a -> [a]   

Computes the list of all values of the given argument according to a given strategy (here: randomized diagonalization of levels with flattening).