com.bonzaiengine.util

Class Trees

java.lang.Object

com.bonzaiengine.util.Trees

public class Trees
extends java.lang.Object

ITree utilities in an iterative tree traversal (no recursion) and continuation approach (minimal memory usage).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Trees.ITreeFunction<T,R>
static class	Trees.Traversal<T,U>

Method Summary

Modifier and Type	Method and Description
static <T extends ITree<T>> int	distance(T root, T leaf)
static <T extends ITree<T>> T	find(T tree, java.util.function.Predicate<T> visitor)
static <V> Tree<V>	findValue(Tree<V> tree, V value) Find a ITree using it's value and the == comparator
static int	indexOfChild(ITree<?> parent, ITree<?> child)
static <T extends ITree<T>> boolean	isParentOf(T parent, T child)
static <V> java.lang.Iterable<Tree<V>>	leafs(Tree<V> tree)
static <T extends ITree<T>> java.lang.Iterable<T>	list(T tree) Pre-order tree listing
static <T extends ITree<T>> java.lang.Iterable<T>	list(T tree, boolean includeTree) Pre-order tree listing
static <T extends ITree<T>> java.lang.Iterable<T>	listFilter(T tree, java.util.function.Predicate<T> filter) Pre-order tree listing
static <T extends ITree<T>> java.lang.Iterable<T>	listUp(T tree) Post-order (deep first) tree listing
static <V> java.lang.Iterable<V>	listValues(Tree<V> tree)
static <V> java.lang.Iterable<V>	listValues(Tree<V> tree, boolean includeRoot)
static <T extends ITree<T>,U extends ITree<U>> U	map(T tree, java.util.function.Function<T,U> mapper) Map a ITree to a ITree using the IMapper to map U to T
static <T extends ITree<T>,U extends ITree<U>> U	mapFilter(T tree, java.util.function.Function<T,U> converter, java.util.function.Predicate<T> filter) Convert a ITree to a ITree using the IMapper to map R to T
static <T extends ITree<T>> Array<T>	pathFrom(T from, T to)
static <T extends ITree<T>> void	visit(T tree, java.util.function.Predicate<T> visitor)
static <T extends ITree<T>,U> void	visit(T tree, U u, java.util.function.BiFunction<T,U,U> visitor)
static <T extends ITree<T>> void	visitIgnoreRoot(T tree, java.util.function.Predicate<? extends T> visitor)

Methods inherited from class java.lang.Object

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

Method Detail

visit

public static final <T extends ITree<T>> void visit(T tree,
                                                    java.util.function.Predicate<T> visitor)

visitIgnoreRoot

public static final <T extends ITree<T>> void visitIgnoreRoot(T tree,
                                                              java.util.function.Predicate<? extends T> visitor)

visit

public static final <T extends ITree<T>,U> void visit(T tree,
                                                      U u,
                                                      java.util.function.BiFunction<T,U,U> visitor)

list

public static final <T extends ITree<T>> java.lang.Iterable<T> list(T tree)

Pre-order tree listing

Parameters:

tree - an ITree to list

Returns:

Iterable over all nodes of the specified ITree

list

public static final <T extends ITree<T>> java.lang.Iterable<T> list(T tree,
                                                                    boolean includeTree)

Pre-order tree listing

Parameters:

tree - an ITree to list

includeTree - false to exclude the specified tree from the Iterable

Returns:

Iterable over all nodes of the specified ITree

listFilter

public static final <T extends ITree<T>> java.lang.Iterable<T> listFilter(T tree,
                                                                          java.util.function.Predicate<T> filter)

Pre-order tree listing

Parameters:

filter - return true to select the visited element in the returned list

Returns:

list containing selected ITree nodes

listUp

public static final <T extends ITree<T>> java.lang.Iterable<T> listUp(T tree)

Post-order (deep first) tree listing

Returns:

Iterable over all nodes of the specified ITree

listValues

public static final <V> java.lang.Iterable<V> listValues(Tree<V> tree)

Parameters:

filter - return true to select the visited element in the returned list

Returns:

list containing selected ITree nodes

listValues

public static final <V> java.lang.Iterable<V> listValues(Tree<V> tree,
                                                         boolean includeRoot)

map

public static final <T extends ITree<T>,U extends ITree<U>> U map(T tree,
                                                                  java.util.function.Function<T,U> mapper)

Map a ITree to a ITree using the IMapper to map U to T

Parameters:

tree - a ITree to map

mapper - an Function

Returns:

the ITree mapped

mapFilter

public static final <T extends ITree<T>,U extends ITree<U>> U mapFilter(T tree,
                                                                        java.util.function.Function<T,U> converter,
                                                                        java.util.function.Predicate<T> filter)

Convert a ITree to a ITree using the IMapper to map R to T

Parameters:

converter - a Function to map R to a T object

Returns:

ITree

find

public static final <T extends ITree<T>> T find(T tree,
                                                java.util.function.Predicate<T> visitor)

Parameters:

visitor - returning true when the value is found

Returns:

the tree node containing this value found, if any

findValue

public static final <V> Tree<V> findValue(Tree<V> tree,
                                          V value)

Find a ITree using it's value and the == comparator

Parameters:

value -

Returns:

the ITree containing the specified object

leafs

public static final <V> java.lang.Iterable<Tree<V>> leafs(Tree<V> tree)

Returns:

the list of ITree leafs connected to this ITree.
a leaf is a ITree with no child.

distance

public static final <T extends ITree<T>> int distance(T root,
                                                      T leaf)

Parameters:

root - a ITree node

leaf - a ITree node

Returns:

the distance between the two nodes, or -1 if root is not a parent of leaf

isParentOf

public static final <T extends ITree<T>> boolean isParentOf(T parent,
                                                            T child)

Parameters:

parent - a ITree node

child - a ITree node

Returns:

true if parent is a (direct or indirect) parent of child
Equivalent to: distance(parent, child) > 0

pathFrom

public static final <T extends ITree<T>> Array<T> pathFrom(T from,
                                                           T to)

Parameters:

from - a ITree node

to - a ITree node

Returns:

list containing the path from the node from to the node to, or an empty list if the path does not exists.
The head (first) and tail (last) elements of the list are respectively from and to

indexOfChild

public static final int indexOfChild(ITree<?> parent,
                                     ITree<?> child)