Module org.meeuw.math.abstractalgebra.test

Package org.meeuw.theories

Interface ComparableTheory<E extends Comparable<E>>

All Superinterfaces:

BasicObjectTheory<E>

All Known Subinterfaces:

CompleteScalarFieldTheory<E>, OrderedTheory<E>, ScalarFieldTheory<E>, ScalarTheory<S>, SizeableScalarTheory<S,SIZE>, StrictlyOrderedTheory<E>

public interface ComparableTheory<E extends Comparable<E>>
extends BasicObjectTheory<E>

Tests basic properties for Comparable objects.

• Normally, equals must be consistent with comparable
• comparing to null should raise NullPointerException
• compare to is anti-commutative
• compareTo is also transitive (compareToIsTransitiveBigger(E, E, E), compareToIsTransitiveSmaller(E, E, E), compareToIsTransitiveEquals(net.jqwik.api.Tuple.Tuple3<E, E, E>))

Since:

0.10

Author:

Michiel Meeuwissen

Field Summary

Fields inherited from interface org.meeuw.theories.BasicObjectTheory

DATAPOINTS, DATAPOINTS_OR_NULL, EQUAL_DATAPOINTS, RANDOMS

Method Summary

Modifier and Type	Method	Description
default net.jqwik.api.Arbitrary<@NonNull net.jqwik.api.Tuple.Tuple3<@NonNull E,@NonNull E,@NonNull E>>	compareToEqualsDatapoints3()
default void	compareToIsAntiCommutative(E x, E y)	The implementor must ensure sgn(x.compareTo(y)) == -sgn(y.compareTo(x)) for all x and y.
default void	compareToIsTransitiveBigger(E x, E y, E z)	The implementor must also ensure that the relation is transitive: (x.compareTo(y)>0 && y.compareTo(z)>0) implies x.compareTo(z)>0.
default void	compareToIsTransitiveEquals(net.jqwik.api.Tuple.Tuple3<E,E,E> tuple)	The implementor must also ensure that the relation is transitive: (x.compareTo(y)==0 && y.compareTo(z)==0) implies x.compareTo(z)==0.
default void	compareToIsTransitiveSmaller(E x, E y, E z)	The implementor must also ensure that the relation is transitive: (x.compareTo(y)<0 && y.compareTo(z)<0) implies x.compareTo(z)<0.
default void	compareToNull(Object o)
default void	equalsConsistentWithComparable(net.jqwik.api.Tuple.Tuple2<E,E> pair)	This test whether compareTo Comparable.compareTo(Object) returns 0 iff if two object are equal.

Methods inherited from interface org.meeuw.theories.BasicObjectTheory

datapoints, datapointsOrNull, equalDatapoints, equals, equalsIsConsistent, equalsIsReflexive, equalsIsSymmetric, equalsIsTransitive, equalsReturnFalseOnNull, equalsReturnFalseOnOtherObject, hashCodeIsConsistentWithEquals, hashCodeIsSelfConsistent, log, randoms, toString

Method Details

equalsConsistentWithComparable

@Property(maxDiscardRatio=10000)
default void equalsConsistentWithComparable(@ForAll("equalDatapoints")
 net.jqwik.api.Tuple.Tuple2<E,E> pair)

This test whether compareTo Comparable.compareTo(Object) returns 0 iff if two object are equal. TODO: This is not an absolute requirement, in some cases you may want to compareTo to zero even if two objects are not exactly equal.

compareToNull

@Property
default void compareToNull(@ForAll("datapoints")
 Object o)

compareToIsAntiCommutative

@Property
default void compareToIsAntiCommutative(@ForAll("datapoints")
 E x,
 @ForAll("datapoints")
 E y)

The implementor must ensure sgn(x.compareTo(y)) == -sgn(y.compareTo(x)) for all x and y.

compareToIsTransitiveBigger

@Property(maxDiscardRatio=1000)
default void compareToIsTransitiveBigger(@ForAll("datapoints")
 E x,
 @ForAll("datapoints")
 E y,
 @ForAll("datapoints")
 E z)

The implementor must also ensure that the relation is transitive: (x.compareTo(y)>0 && y.compareTo(z)>0) implies x.compareTo(z)>0.

compareToIsTransitiveSmaller

@Property(maxDiscardRatio=1000)
default void compareToIsTransitiveSmaller(@ForAll("datapoints")
 E x,
 @ForAll("datapoints")
 E y,
 @ForAll("datapoints")
 E z)

The implementor must also ensure that the relation is transitive: (x.compareTo(y)<0 && y.compareTo(z)<0) implies x.compareTo(z)<0.

compareToIsTransitiveEquals

@Property
default void compareToIsTransitiveEquals(@ForAll("compareToEqualsDatapoints3")
 net.jqwik.api.Tuple.Tuple3<E,E,E> tuple)

The implementor must also ensure that the relation is transitive: (x.compareTo(y)==0 && y.compareTo(z)==0) implies x.compareTo(z)==0.

compareToEqualsDatapoints3

@Provide
default net.jqwik.api.Arbitrary<@NonNull net.jqwik.api.Tuple.Tuple3<@NonNull E,@NonNull E,@NonNull E>> compareToEqualsDatapoints3()