org.parboiled.trees

Class GraphUtils

java.lang.Object

org.parboiled.trees.GraphUtils

public final class GraphUtils
extends java.lang.Object

General utility methods for operating on directed graphs (consisting of GraphNodes).

Method Summary

Modifier and Type	Method and Description
static <T extends GraphNode<T>,C extends java.util.Collection<T>> C	collectAllNodes(T node, C collection) Collects all nodes from the graph reachable from the given node in the given collection.
static <T extends GraphNode<T>> int	countAllDistinct(T node) Counts all distinct nodes in the graph reachable from the given node.
static <T extends GraphNode<T>> T	getFirstChild(T node) Returns the first child node of the given node or null if node is null or does not have any children.
static <T extends GraphNode<T>> T	getLastChild(T node) Returns the last child node of the given node or null if node is null or does not have any children.
static boolean	hasChildren(GraphNode<?> node) Returns true if this node is not null and has at least one child node.
static <T extends GraphNode<T>> java.lang.String	printTree(T node, Formatter<T> formatter) Creates a string representation of the graph reachable from the given node using the given formatter.
static <T extends GraphNode<T>> java.lang.String	printTree(T node, Formatter<T> formatter, Predicate<T> nodeFilter, Predicate<T> subTreeFilter) Creates a string representation of the graph reachable from the given node using the given formatter.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

hasChildren

public static boolean hasChildren(GraphNode<?> node)

Returns true if this node is not null and has at least one child node.

Parameters:

node - a node

Returns:

true if this node is not null and has at least one child node.

getFirstChild

public static <T extends GraphNode<T>> T getFirstChild(T node)

Returns the first child node of the given node or null if node is null or does not have any children.

Parameters:

node - a node

Returns:

the first child node of the given node or null if node is null or does not have any children

getLastChild

public static <T extends GraphNode<T>> T getLastChild(T node)

Returns the last child node of the given node or null if node is null or does not have any children.

Parameters:

node - a node

Returns:

the last child node of the given node or null if node is null or does not have any children

countAllDistinct

public static <T extends GraphNode<T>> int countAllDistinct(T node)

Counts all distinct nodes in the graph reachable from the given node. This method can properly deal with cycles in the graph.

Parameters:

node - the root node

Returns:

the number of distinct nodes

collectAllNodes

public static <T extends GraphNode<T>,C extends java.util.Collection<T>> C collectAllNodes(T node,
                                                                                           C collection)

Collects all nodes from the graph reachable from the given node in the given collection. This method can properly deal with cycles in the graph.

Parameters:

node - the root node

collection - the collection to collect into

Returns:

the same collection passed as a parameter

printTree

public static <T extends GraphNode<T>> java.lang.String printTree(T node,
                                                                  Formatter<T> formatter)

Creates a string representation of the graph reachable from the given node using the given formatter.

Parameters:

node - the root node

formatter - the node formatter

Returns:

a new string

printTree

public static <T extends GraphNode<T>> java.lang.String printTree(T node,
                                                                  Formatter<T> formatter,
                                                                  Predicate<T> nodeFilter,
                                                                  Predicate<T> subTreeFilter)

Creates a string representation of the graph reachable from the given node using the given formatter. The given filter predicated determines whether a particular node (and its subtree respectively) is to be printed or not.

Parameters:

node - the root node

formatter - the node formatter

nodeFilter - the predicate selecting the nodes to print

subTreeFilter - the predicate determining whether to descend into a given nodes subtree or not

Returns:

a new string