Package com.google.common.graph

Class EndpointPair<N>

java.lang.Object

com.google.common.graph.EndpointPair<N>

All Implemented Interfaces:

java.lang.Iterable<N>

Direct Known Subclasses:

EndpointPair.Ordered, EndpointPair.Unordered

public abstract class EndpointPair<N>
extends java.lang.Object
implements java.lang.Iterable<N>

An immutable pair representing the two endpoints of an edge in a graph. The EndpointPair of a directed edge is an ordered pair of nodes (source() and target()). The EndpointPair of an undirected edge is an unordered pair of nodes (nodeU() and nodeV()).

The edge is a self-loop if, and only if, the two endpoints are equal.

Since:

20.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	EndpointPair.Ordered<N>
private static class	EndpointPair.Unordered<N>

Field Summary

Fields

Modifier and Type	Field	Description
private N	nodeU
private N	nodeV

Constructor Summary

Constructors

Modifier	Constructor	Description
private	EndpointPair(N nodeU, N nodeV)

Method Summary

Modifier and Type	Method	Description
N	adjacentNode(java.lang.Object node)	Returns the node that is adjacent to node along the origin edge.
abstract boolean	equals(java.lang.Object obj)	Two ordered EndpointPairs are equal if their source() and target() are equal.
abstract int	hashCode()	The hashcode of an ordered EndpointPair is equal to Objects.hashCode(source(), target()).
abstract boolean	isOrdered()	Returns true if this EndpointPair is an ordered pair (i.e.
UnmodifiableIterator<N>	iterator()	Iterates in the order nodeU(), nodeV().
N	nodeU()	If this EndpointPair isOrdered() returns the source(); otherwise, returns an arbitrary (but consistent) endpoint of the origin edge.
N	nodeV()	Returns the node adjacent to nodeU() along the origin edge.
(package private) static <N> EndpointPair<N>	of(Graph<?> graph, N nodeU, N nodeV)	Returns an EndpointPair representing the endpoints of an edge in graph.
(package private) static <N> EndpointPair<N>	of(Network<?,?> network, N nodeU, N nodeV)	Returns an EndpointPair representing the endpoints of an edge in network.
static <N> EndpointPair<N>	ordered(N source, N target)	Returns an EndpointPair representing the endpoints of a directed edge.
abstract N	source()	If this EndpointPair isOrdered(), returns the node which is the source.
abstract N	target()	If this EndpointPair isOrdered(), returns the node which is the target.
static <N> EndpointPair<N>	unordered(N nodeU, N nodeV)	Returns an EndpointPair representing the endpoints of an undirected edge.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

nodeU

private final N nodeU

nodeV

private final N nodeV

Constructor Detail

EndpointPair

private EndpointPair(N nodeU,
                     N nodeV)

Method Detail

ordered

public static <N> EndpointPair<N> ordered(N source,
                                          N target)

Returns an EndpointPair representing the endpoints of a directed edge.

unordered

public static <N> EndpointPair<N> unordered(N nodeU,
                                            N nodeV)

Returns an EndpointPair representing the endpoints of an undirected edge.

of

static <N> EndpointPair<N> of(Graph<?> graph,
                              N nodeU,
                              N nodeV)

Returns an EndpointPair representing the endpoints of an edge in graph.

of

static <N> EndpointPair<N> of(Network<?,?> network,
                              N nodeU,
                              N nodeV)

Returns an EndpointPair representing the endpoints of an edge in network.

source

public abstract N source()

If this EndpointPair isOrdered(), returns the node which is the source.

Throws:

java.lang.UnsupportedOperationException - if this EndpointPair is not ordered

target

public abstract N target()

If this EndpointPair isOrdered(), returns the node which is the target.

Throws:

java.lang.UnsupportedOperationException - if this EndpointPair is not ordered

nodeU

public final N nodeU()

If this EndpointPair isOrdered() returns the source(); otherwise, returns an arbitrary (but consistent) endpoint of the origin edge.

nodeV

public final N nodeV()

Returns the node adjacent to nodeU() along the origin edge. If this EndpointPair isOrdered(), this is equal to target().

adjacentNode

public final N adjacentNode(java.lang.Object node)

Returns the node that is adjacent to node along the origin edge.

Throws:

java.lang.IllegalArgumentException - if this EndpointPair does not contain node

isOrdered

public abstract boolean isOrdered()

Returns true if this EndpointPair is an ordered pair (i.e. represents the endpoints of a directed edge).

iterator

public final UnmodifiableIterator<N> iterator()

Iterates in the order nodeU(), nodeV().

Specified by:

iterator in interface java.lang.Iterable<N>

equals

public abstract boolean equals(java.lang.Object obj)

Two ordered EndpointPairs are equal if their source() and target() are equal. Two unordered EndpointPairs are equal if they contain the same nodes. An ordered EndpointPair is never equal to an unordered EndpointPair.

Overrides:

equals in class java.lang.Object

hashCode

public abstract int hashCode()

The hashcode of an ordered EndpointPair is equal to Objects.hashCode(source(), target()). The hashcode of an unordered EndpointPair is equal to nodeU().hashCode() + nodeV().hashCode().

Overrides:

hashCode in class java.lang.Object