
 Type Parameters:
V
 the graph vertex typeE
 the graph edge type
 All Known Implementing Classes:
DefaultGraphIterables
public interface GraphIterables<V,E>
Presents a graph as a collection of views suitable for graphs which contain a very large number of vertices or edges. Graph algorithms written these methods can work with graphs without the restrictions imposed by 32bit arithmetic.Whether the returned iterators support removal of elements is left to the graph implementation. It is the responsibility of callers who rely on this behavior to only use graph implementations which support it.
 Author:
 Dimitrios Michail


Method Summary
All Methods Instance Methods Abstract Methods Default Methods Modifier and Type Method Description default java.lang.Iterable<E>
allEdges(V sourceVertex, V targetVertex)
Returns an iterable view over all edges connecting source vertex to target vertex if such vertices exist in this graph.default long
degreeOf(V vertex)
Returns the degree of the specified vertex.default long
edgeCount()
Return the number of edges in the graph.default java.lang.Iterable<E>
edges()
Returns an iterable over the edges of the graph.default java.lang.Iterable<E>
edgesOf(V vertex)
Returns an iterable view over all edges touching the specified vertex.Graph<V,E>
getGraph()
Get the underlying graph.default java.lang.Iterable<E>
incomingEdgesOf(V vertex)
Returns an iterable view over all edges incoming into the specified vertex.default long
inDegreeOf(V vertex)
Returns the "in degree" of the specified vertex.default long
outDegreeOf(V vertex)
Returns the "out degree" of the specified vertex.default java.lang.Iterable<E>
outgoingEdgesOf(V vertex)
Returns an iterable view over all edges outgoing into the specified vertex.default long
vertexCount()
Return the number of vertices in the graph.default java.lang.Iterable<V>
vertices()
Returns an iterable view over the vertices contained in this graph.



Method Detail

edges
default java.lang.Iterable<E> edges()
Returns an iterable over the edges of the graph.Whether the ordering is deterministic, depends on the actual graph implementation. It is the responsibility of callers who rely on this behavior to only use graph implementations which support it.
 Returns:
 an iterable over the edges of the graph.

edgeCount
default long edgeCount()
Return the number of edges in the graph. Returns:
 the number of edges.

vertices
default java.lang.Iterable<V> vertices()
Returns an iterable view over the vertices contained in this graph. The returned iterator is a live view of the vertices. If the graph is modified while an iteration is in progress, the results of the iteration are undefined.The graph implementation may maintain a particular ordering for deterministic iteration, but this is not required. It is the responsibility of callers who rely on this behavior to only use graph implementations which support it.
 Returns:
 an iterable view of the vertices contained in this graph

vertexCount
default long vertexCount()
Return the number of vertices in the graph. Returns:
 the number of vertices

edgesOf
default java.lang.Iterable<E> edgesOf(V vertex)
Returns an iterable view over all edges touching the specified vertex. The returned iterators are live views. If the graph is modified while an iteration is in progress, the results of the iteration are undefined. If no edges are touching the specified vertex, the returned iterators are already exhausted. Parameters:
vertex
 input vertex Returns:
 an iterable view of the vertices contained in this graph
 Throws:
java.lang.IllegalArgumentException
 if vertex is not found in the graph.java.lang.NullPointerException
 if vertex isnull
.

degreeOf
default long degreeOf(V vertex)
Returns the degree of the specified vertex.A degree of a vertex in an undirected graph is the number of edges touching that vertex. Edges with same source and target vertices (selfloops) are counted twice.
In directed graphs this method returns the sum of the "in degree" and the "out degree".
 Parameters:
vertex
 vertex whose degree is to be calculated. Returns:
 the degree of the specified vertex.
 Throws:
java.lang.IllegalArgumentException
 if vertex is not found in the graph.java.lang.NullPointerException
 if vertex isnull
.

incomingEdgesOf
default java.lang.Iterable<E> incomingEdgesOf(V vertex)
Returns an iterable view over all edges incoming into the specified vertex. The returned iterators are live views. If the graph is modified while an iteration is in progress, the results of the iteration are undefined.In the case of undirected graphs the returned iterators return all edges touching the vertex, thus, some of the returned edges may have their source and target vertices in the opposite order.
 Parameters:
vertex
 input vertex Returns:
 an iterable view of all edges incoming into the specified vertex
 Throws:
java.lang.IllegalArgumentException
 if vertex is not found in the graph.java.lang.NullPointerException
 if vertex isnull
.

inDegreeOf
default long inDegreeOf(V vertex)
Returns the "in degree" of the specified vertex.The "in degree" of a vertex in a directed graph is the number of inward directed edges from that vertex. See http://mathworld.wolfram.com/Indegree.html.
In the case of undirected graphs this method returns the number of edges touching the vertex. Edges with same source and target vertices (selfloops) are counted twice.
 Parameters:
vertex
 vertex whose degree is to be calculated. Returns:
 the degree of the specified vertex.
 Throws:
java.lang.IllegalArgumentException
 if vertex is not found in the graph.java.lang.NullPointerException
 if vertex isnull
.

outgoingEdgesOf
default java.lang.Iterable<E> outgoingEdgesOf(V vertex)
Returns an iterable view over all edges outgoing into the specified vertex. The returned iterators are live views. If the graph is modified while an iteration is in progress, the results of the iteration are undefined.In the case of undirected graphs the returned iterators return all edges touching the vertex, thus, some of the returned edges may have their source and target vertices in the opposite order.
 Parameters:
vertex
 input vertex Returns:
 an iterable view of all edges outgoing from the specified vertex
 Throws:
java.lang.IllegalArgumentException
 if vertex is not found in the graph.java.lang.NullPointerException
 if vertex isnull
.

outDegreeOf
default long outDegreeOf(V vertex)
Returns the "out degree" of the specified vertex.The "out degree" of a vertex in a directed graph is the number of outward directed edges from that vertex. See http://mathworld.wolfram.com/Outdegree.html.
In the case of undirected graphs this method returns the number of edges touching the vertex. Edges with same source and target vertices (selfloops) are counted twice.
 Parameters:
vertex
 vertex whose degree is to be calculated. Returns:
 the degree of the specified vertex.
 Throws:
java.lang.IllegalArgumentException
 if vertex is not found in the graph.java.lang.NullPointerException
 if vertex isnull
.

allEdges
default java.lang.Iterable<E> allEdges(V sourceVertex, V targetVertex)
Returns an iterable view over all edges connecting source vertex to target vertex if such vertices exist in this graph. The returned iterators are live views. If the graph is modified while an iteration is in progress, the results of the iteration are undefined. If any of the vertices does not exist or isnull
, returnsnull
. If both vertices exist but no edges found, returns an iterable which returns exhausted iterators.In undirected graphs, some of the returned edges may have their source and target vertices in the opposite order. In simple graphs the returned set is either singleton set or empty set.
 Parameters:
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge. Returns:
 an iterable view of all edges connecting source to target vertex.
 Throws:
java.lang.IllegalArgumentException
 if vertex is not found in the graph.java.lang.NullPointerException
 if vertex isnull
.

