org.codefx.libfx.collection.transform

Class TransformingListIterator<I,O>

java.lang.Object

org.codefx.libfx.collection.transform.TransformingListIterator<I,O>

Type Parameters:

I - the inner type, i.e. the type of the elements returned by the wrapped/inner list iterator

O - the outer type, i.e. the type of elements returned by this list iterator

All Implemented Interfaces:

Iterator<O>, ListIterator<O>

public final class TransformingListIterator<I,O>
extends Object

A ListIterator which wraps another list iterator and transforms elements from an inner type I to an outer type O and vice versa.

The transformation of null elements of either inner or outer type is fixed to null -> null. The transformation functions specified during construction do not have to handle null input elements and are not allowed to produce a null result.

Constructor Summary

Constructors

Constructor and Description
TransformingListIterator(ListIterator<I> innerListIterator, Function<? super I,? extends O> transformToOuter, Function<? super O,? extends I> transformToInner) Creates a new transforming list iterator.

Method Summary

Modifier and Type	Method and Description
void	add(O element)
void	forEachRemaining(Consumer<? super O> action)
protected ListIterator<I>	getInnerIterator()
boolean	hasNext()
boolean	hasPrevious()
O	next()
int	nextIndex()
O	previous()
int	previousIndex()
void	remove()
void	set(O element)
protected I	transformToInner(O outerElement) Transforms an element from the outer type O to the inner type I.
protected O	transformToOuter(I innerElement) Transforms an element from the inner type I to the outer type O.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.ListIterator

hasNext, next, remove

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

TransformingListIterator

public TransformingListIterator(ListIterator<I> innerListIterator,
                                Function<? super I,? extends O> transformToOuter,
                                Function<? super O,? extends I> transformToInner)

Creates a new transforming list iterator.

If the specified list iterator is used by any other instance, the behavior is undefined. The specified transform functions will not be called with null elements and are not allowed to return null.

Parameters:

innerListIterator - the wrapped/inner list iterator

transformToOuter - transforms elements from the inner type I to the outer type O

transformToInner - transforms elements from the outer type O to the inner type I

Method Detail

getInnerIterator

protected ListIterator<I> getInnerIterator()

Returns:

the wrapped/inner iterator

transformToOuter

protected O transformToOuter(I innerElement)

Transforms an element from the inner type I to the outer type O.

Parameters:

innerElement - an element returned by the innerIterator

Returns:

an equivalent element of type O

transformToInner

protected I transformToInner(O outerElement)

Transforms an element from the outer type O to the inner type I.

Parameters:

outerElement - an element specified as an argument to a method call

Returns:

an equivalent element of type I

hasPrevious

public boolean hasPrevious()

Specified by:

hasPrevious in interface ListIterator<O>

nextIndex

public int nextIndex()

Specified by:

nextIndex in interface ListIterator<O>

previousIndex

public int previousIndex()

Specified by:

previousIndex in interface ListIterator<O>

previous

public O previous()

Specified by:

previous in interface ListIterator<O>

add

public void add(O element)

Specified by:

add in interface ListIterator<O>

set

public void set(O element)

Specified by:

set in interface ListIterator<O>

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<O>

next

public O next()

Specified by:

next in interface Iterator<O>

remove

public void remove()

Specified by:

remove in interface Iterator<O>

forEachRemaining

public void forEachRemaining(Consumer<? super O> action)

Specified by:

forEachRemaining in interface Iterator<O>