uk.co.strangeskies.collection

Class ListTransformationView<F,T>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<T>

uk.co.strangeskies.collection.ListTransformationView<F,T>

Type Parameters:

T - The type of the elements of this list.

F - The type of the elements of the backing list.

All Implemented Interfaces:

java.lang.Iterable<T>, java.util.Collection<T>, java.util.List<T>

public class ListTransformationView<F,T>
extends java.util.AbstractList<T>

A view of a list which will be automatically updated along with the original, but who's elements will be a transformation of the original associated elements by way of the function passed to the constructor. The implementation employs lazy evaluation, so try to use get() as little as possible by reusing the result.

Unlike the Stream.map(Function) function, which can provide similar functionality in certain circumstances, this class provides a view which is reusable and backed by the original collection, such that it will reflect changes.

If the constructor is supplied with an InvertibleFunction, it will be possible to add elements to this collection.

Field Summary

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor and Description
ListTransformationView(java.util.List<F> backingCollection, java.util.function.Function<? super F,? extends T> function)
ListTransformationView(java.util.List<F> backingCollection, InvertibleFunction<F,T> function)

Method Summary

Modifier and Type	Method and Description
void	add(int index, T element)
T	get(int index)
java.util.List<F>	getBackingCollection()
InvertibleFunction<F,T>	getFunction()
protected java.util.List<F>	getModifiablebackingCollection()
T	remove(int index)
T	set(int index, T element)
int	size()

Methods inherited from class java.util.AbstractList

add, addAll, clear, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, remove, removeAll, replaceAll, retainAll, sort, spliterator, toArray, toArray

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

ListTransformationView

public ListTransformationView(java.util.List<F> backingCollection,
                              java.util.function.Function<? super F,? extends T> function)

Parameters:

backingCollection - The backing collection this class presents a view over.

function - The function which transforms elements into the form in which they are represented in by this view.

ListTransformationView

public ListTransformationView(java.util.List<F> backingCollection,
                              InvertibleFunction<F,T> function)

Parameters:

backingCollection - The backing collection this class presents a view over.

function - The function which transforms elements into the form in which they are represented in by this view.

Method Detail

set

public T set(int index,
             T element)

Specified by:

set in interface java.util.List<T>

Overrides:

set in class java.util.AbstractList<T>

add

public void add(int index,
                T element)

Specified by:

add in interface java.util.List<T>

Overrides:

add in class java.util.AbstractList<T>

remove

public T remove(int index)

Specified by:

remove in interface java.util.List<T>

Overrides:

remove in class java.util.AbstractList<T>

get

public final T get(int index)

Specified by:

get in interface java.util.List<T>

Specified by:

get in class java.util.AbstractList<T>

getFunction

public final InvertibleFunction<F,T> getFunction()

Returns:

The function which transforms elements into the form in which they are represented in by this view.

getBackingCollection

public final java.util.List<F> getBackingCollection()

Returns:

The backing collection this class presents a view over.

getModifiablebackingCollection

protected final java.util.List<F> getModifiablebackingCollection()

size

public final int size()

Specified by:

size in interface java.util.Collection<T>

Specified by:

size in interface java.util.List<T>

Specified by:

size in class java.util.AbstractCollection<T>