org.helenus.commons.collections

Interface DirectedGraph<T>

Type Parameters:

T - the type of elements in this graph

All Superinterfaces:

Collection<T>, Iterable<T>, Set<T>

All Known Implementing Classes:

ConcurrentHashDirectedGraph

public interface DirectedGraph<T>
extends Set<T>

The DirectedGraph interface provides a collection of nodes with outgoing edges to other nodes.

Since:

2.0

Version:

1 - Jan 15, 2015 - paouelle - Creation

Author:

The Helenus Driver Project Authors

Copyright:

2015-2015 The Helenus Driver Project Authors

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	DirectedGraph.Node<T> The Node interface represents a specific node in this directed graph.

Method Summary

Modifier and Type	Method and Description
void	add(T start, java.util.stream.Stream<T> dests) Adds the specified nodes if they don't exist in the graph and build arcs from the starting node to all the destination ones.
void	add(T start, T dest) Adds the specified nodes if they don't exist in the graph and build an arc from the starting node to the destination one.
void	addEdge(T start, T dest) Adds an arc from the starting node to the destination one.
boolean	edgeExists(T start, T dest) Given two nodes in the graph, returns whether there is an edge from the first node to the second node.
java.util.stream.Stream<T>	edgesFrom(T node) Given a node in the graph, returns a stream of the edges leaving that node.
DirectedGraph.Node<T>	get(T val) Gets a node from this graph given its value.
Set<T>	getEdgesFrom(T node) Given a node in the graph, returns an immutable view of the edges leaving that node as a set of endpoints.
Set<DirectedGraph.Node<T>>	nodeSet() Gets a Set view of all the nodes contained in this directed graph.
boolean	removeEdge(T start, T dest) Removes the edge from the specified starting node to the specified destination node from the graph.

Methods inherited from interface java.util.Set

add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, spliterator, toArray, toArray

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Method Detail

get

DirectedGraph.Node<T> get(T val)

Gets a node from this graph given its value.

Parameters:

val - the value for the node to retrieve

Returns:

the corresponding node from this graph or null if the graph doesn't contain a node with the specified value

nodeSet

Set<DirectedGraph.Node<T>> nodeSet()

Gets a Set view of all the nodes contained in this directed graph.

The set is backed by the graph, so changes to the graph are reflected in the set, and vice-versa. If the graph is modified while an iteration over the set is in progress (except through the iterator's own remove() operation, or through the addEdge() or removeEdge() operations on a graph node returned by the iterator) the results of the iteration are undefined. The set supports node removal, which removes the corresponding node from the graph, via the Iterator.remove(), Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.

Returns:

a set view of the nodes contained in this graph

add

void add(T start,
         T dest)

Adds the specified nodes if they don't exist in the graph and build an arc from the starting node to the destination one.

Parameters:

start - the starting node

dest - the destination node

add

void add(T start,
         java.util.stream.Stream<T> dests)

Adds the specified nodes if they don't exist in the graph and build arcs from the starting node to all the destination ones.

Parameters:

start - the starting node

dests - the destination nodes

addEdge

void addEdge(T start,
             T dest)

Adds an arc from the starting node to the destination one. If an arc already exists, this operation is a no-op.

Parameters:

start - the starting node

dest - the destination node

Throws:

NoSuchElementException - if either nodes do not exist

removeEdge

boolean removeEdge(T start,
                   T dest)

Removes the edge from the specified starting node to the specified destination node from the graph.

Parameters:

start - the starting node

dest - the destination node

Returns:

true if an edge was removed; false otherwise

Throws:

NoSuchElementException - if either nodes do not exist

edgeExists

boolean edgeExists(T start,
                   T dest)

Given two nodes in the graph, returns whether there is an edge from the first node to the second node.

Parameters:

start - the starting node

dest - the destination node

Returns:

true if an edge exists from start to dest; falseotherwise

Throws:

NoSuchElementException - if either nodes do not exist

edgesFrom

java.util.stream.Stream<T> edgesFrom(T node)

Given a node in the graph, returns a stream of the edges leaving that node.

Parameters:

node - the node whose edges should be queried

Returns:

a stream of the edges leaving that node

Throws:

NoSuchElementException - if the node does not exist

getEdgesFrom

Set<T> getEdgesFrom(T node)

Given a node in the graph, returns an immutable view of the edges leaving that node as a set of endpoints.

Parameters:

node - the node whose edges should be queried

Returns:

an immutable view of the edges leaving that node

Throws:

NoSuchElementException - if the node does not exist