This module defines the interface of properties that can be checked with the CurryCheck tool, an automatic propertybased test tool based on the EasyCheck library. The ideas behind EasyCheck are described in this paper. CurryCheck automatically tests properties defined with this library. CurryCheck supports the definition of unit tests (also for I/O operations) and property tests parameterized over some arguments. CurryCheck is described in more detail in this paper.
Basically, this module is a stub clone of the EasyCheck library which contains only the interface of the operations used to specify properties. Hence, this library does not import any other library. This supports the definition of properties in any other module (execept for the prelude).
Author: Sebastian Fischer (with extensions by Michael Hanus)
Version: April 2017
returns
:: IO a > a > PropIO
The property returns a x
is satisfied if the execution of the
I/O action a
returns the value x .

sameReturns
:: 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.

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.

(=)
:: a > a > Prop
The property x = y
is satisfied if x
and y
have deterministic
values that are equal.

(<~>)
:: a > a > Prop
The property x <~> y
is satisfied if the sets of the values of
x
and y
are equal.

(~>)
:: a > a > Prop
The property x ~> y
is satisfied if x
evaluates to every value of y .

(<~)
:: a > a > Prop
The property x <~ y
is satisfied if y
evaluates to every value of x .

(<~~>)
:: a > a > Prop
The property x <~~> y
is satisfied if the multisets of the values of
x
and y
are equal.

(==>)
:: Bool > Prop > Prop
A conditional property is tested if the condition evaluates to True .

solutionOf
:: (a > Bool) > a
solutionOf p
returns (nondeterministically) a solution
of predicate p .

is
:: a > (a > Bool) > Prop
The property is x p
is satisfied if x
has a deterministic value
which satisfies p .

isAlways
:: a > (a > Bool) > Prop
The property isAlways x p
is satisfied if all values of x
satisfy p .

isEventually
:: a > (a > Bool) > Prop
The property isEventually x p
is satisfied if some value of x
satisfies p .

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
:: a > Prop
The property failing x
is satisfied if x
has no value.

successful
:: a > Prop
The property successful x
is satisfied if x
has at least one value.

deterministic
:: a > Prop
The property deterministic x
is satisfied if x
has exactly one value.

(#)
:: a > Int > Prop
The property x # n
is satisfied if x
has n
values.

(#<)
:: a > Int > Prop
The property x #< n
is satisfied if x
has less than n
values.

(#>)
:: a > Int > Prop
The property x #> n
is satisfied if x
has more than n
values.

for
:: a > (a > Prop) > Prop
The property for x p
is satisfied if all values y
of x
satisfy property p y .

forAll
:: [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.

label
:: String > Prop > Prop
Assign a label to a property. 
classify
:: Bool > String > Prop > Prop
Assign a label to a property if the first argument is True .

trivial
:: Bool > Prop > Prop
Assign the label "trivial" to a property if the first argument is True .

collect
:: a > Prop > Prop
Assign a label showing the given argument to a property. 
collectAs
:: String > a > Prop > Prop
Assign a label showing a given name and the given argument to a property. 
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). 
Abstract type to represent properties involving IO actions.
Constructors:
Abstract type to represent properties to be checked. Basically, it contains all tests to be executed to check the property.
Constructors:
The property

The property

The property 
The property 
The property

The property

The property

The property

The property

A conditional property is tested if the condition evaluates to


The property

The property

The property

The property 
The property 
The property 
The property 
The property

The property

The property

The property 
The property 
The property

Assign a label to a property. All labeled tests are counted and shown at the end. 
Assign a label to a property if the first argument is multIsComm x y = classify (x<0  y<0) "Negative" $ x*y = y*x 
Assign the label "trivial" to a property if the first argument is

Assign a label showing the given argument to a property. All labeled tests are counted and shown at the end. 
Assign a label showing a given name and the given argument to a property. All labeled tests are counted and shown at the end. 
Computes the list of all values of the given argument according to a given strategy (here: randomized diagonalization of levels with flattening). 