Package io.github.oliviercailloux.j_voting.preferences.classes

Class MutablePreferenceImpl

java.lang.Object

io.github.oliviercailloux.j_voting.preferences.classes.MutablePreferenceImpl

All Implemented Interfaces:

MutablePreference, Preference

public class MutablePreferenceImpl
extends Object
implements MutablePreference

Implements MutablePreference interface. The structure of a MutablePreference is a MutableGraph in which an edge represents the relation "at least as good as".

See Also:

Preference, MutablePreference

Field Summary

Fields

Modifier and Type	Field	Description
protected Set<Alternative>	alternatives
protected MutableGraph<Alternative>	graph
protected Voter	voter

Method Summary

Modifier and Type	Method	Description
void	addAlternative(Alternative alternative)	Adds an alternative to the Preference.
void	addEquivalence(Alternative a1, Alternative a2)	Adds an edge from an alternative a1 to an alternative a2 and from a2 to a1.
ImmutableGraph<Alternative>	asGraph()	In the graph : a relation from a to b means "a is at least as good as b".
MutableGraph<Alternative>	asMutableGraph()	This graph is not necessarily transitive and not necessarily reflexive.
boolean	equals(Object obj)
Set<Alternative>	getAlternatives()	The returned set reads through this object: if this object is mutable, any modification to this object modifies the returned set, and conversely.
Voter	getVoter()
static MutablePreferenceImpl	given(Preference pref)	Factory method making new MutablePreference from an other Preference.
static MutablePreferenceImpl	given(Voter voter)
static MutablePreference	given(Voter voter, MutableGraph<Alternative> pref)
void	setAsLeastAsGood(Alternative a1, Alternative a2)	Adds an edge from an alternative a1 to an alternative a2, so that a1 is as least as good as a2 (a1 >= a2).
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

voter

protected Voter voter

graph

protected MutableGraph<Alternative> graph

alternatives

protected Set<Alternative> alternatives

Method Detail

given

public static MutablePreference given(Voter voter,
                                      MutableGraph<Alternative> pref)

Parameters:

pref - is a mutable graph of alternatives representing the preference. Each node of the graph contains a set, if this set contains several alternatives, it means that those alternatives are ex-aequo

voter - is the Voter associated to the Preference.

Returns:

the mutable preference

See Also:

Voter

given

public static MutablePreferenceImpl given(Voter voter)

Parameters:

voter - is the Voter associated to the Preference.

Returns:

a MutablePreference with the same voter and an empty graph

given

public static MutablePreferenceImpl given(Preference pref)

Factory method making new MutablePreference from an other Preference. It creates a new similar graph instance (mutable). The voter instance of the created preference is the same as the copied preference.

Parameters:

pref - a Preference

Returns:

a copy of this preference as a MutablePreference, with the same voter.

asGraph

public ImmutableGraph<Alternative> asGraph()

Description copied from interface: Preference

In the graph : a relation from a to b means "a is at least as good as b". This graph can’t be modified, but is not necessarily immutable. Reflexive and transitive.

Specified by:

asGraph in interface Preference

Returns:

the Graph corresponding to the Preference

asMutableGraph

public MutableGraph<Alternative> asMutableGraph()

Description copied from interface: MutablePreference

This graph is not necessarily transitive and not necessarily reflexive.

Specified by:

asMutableGraph in interface MutablePreference

addAlternative

public void addAlternative(Alternative alternative)

Description copied from interface: MutablePreference

Adds an alternative to the Preference. This alternative is not preferred to any other of the preference, it is being added isolated.

Specified by:

addAlternative in interface MutablePreference

Parameters:

alternative - to add to the preference.

addEquivalence

public void addEquivalence(Alternative a1,
                           Alternative a2)

Description copied from interface: MutablePreference

Adds an edge from an alternative a1 to an alternative a2 and from a2 to a1. If one of them is not in the graph, they are added. a1 and a2 are ex-aequo.

Specified by:

addEquivalence in interface MutablePreference

Parameters:

a1 - first alternative

a2 - second alternative

setAsLeastAsGood

public void setAsLeastAsGood(Alternative a1,
                             Alternative a2)

Description copied from interface: MutablePreference

Adds an edge from an alternative a1 to an alternative a2, so that a1 is as least as good as a2 (a1 >= a2). If one of them is not in the graph, they are added.

Specified by:

setAsLeastAsGood in interface MutablePreference

Parameters:

a1 - preferred alternative to a2

a2 - "lower" alternative

getAlternatives

public Set<Alternative> getAlternatives()

Description copied from interface: Preference

The returned set reads through this object: if this object is mutable, any modification to this object modifies the returned set, and conversely.

Specified by:

getAlternatives in interface Preference

Returns:

an immutable set of all alternatives of the preference

getVoter

public Voter getVoter()

Specified by:

getVoter in interface Preference

Returns:

Voter instance of the preference, Returns the voter 0 if no specific voter is associated to this preference

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object