Package eu.bandm.tools.util.java

Class Iterators.Pairwise<T>

java.lang.Object

eu.bandm.tools.util.java.Iterators.Pairwise<T>

Enclosing class:

Iterators

public abstract static class Iterators.Pairwise<T>
extends Object

Visitor which performs the method first(Object) for the first element of an Iterable; afterwards the methodpairwise(Object,Object) for each pair of adjacent elements, and at last the method last(Object). These all are performed by invoking process().

Field Summary

Fields

Modifier and Type	Field	Description
protected T	_last	Internal register for the precedingly visited item.
protected final Iterator<T>	it	The iterator which drives the visiting order.
protected final @Opt ListIterator<T>	lit	Identic to it iff the constructor wiht ListIterator has been called.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Pairwise(Iterable<T> it)	Constructor which does not assume the Iterator to be a ListIterator.
protected	Pairwise(Iterator<T> it)	Constructor which does not assume the Iterator to be a ListIterator.
protected	Pairwise(List<T> it)	Constructor which assumes that the Iterator is a ListIterator.
protected	Pairwise(ListIterator<T> lit)	Constructor which assumes that the Iterator is a ListIterator.

Method Summary

Modifier and Type	Method	Description
void	first(T t)	Can be overridden by the user to visit the very first element before the first pair is visited by pairwise(Object,Object).
void	last(T t)	Can be overridden by the user to visit the very last element after the last pair is visited by pairwise(Object,Object).
abstract void	pairwise(T t1, T t2)	Must be overridden by the user to visit the define what to do with each pair of adjacent elements.
void	process()	Central public service provision to visit all wlements in the order of the given (List-) Iterator, executing first(Object), pairwise(Object,Object), and last(Object) in this sequential order.

Methods inherited from class java.lang.Object

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

Field Details

it

protected final Iterator<T> it

The iterator which drives the visiting order.

lit

@Opt
protected final @Opt ListIterator<T> lit

Identic to it iff the constructor wiht ListIterator has been called. Otherwise null. Can be used by payload code for remove operation, etc.

_last

protected T _last

Internal register for the precedingly visited item.

Constructor Details

Pairwise

protected Pairwise(Iterable<T> it)

Constructor which does not assume the Iterator to be a ListIterator.

Pairwise

protected Pairwise(List<T> it)

Constructor which assumes that the Iterator is a ListIterator.

Pairwise

protected Pairwise(ListIterator<T> lit)

Constructor which assumes that the Iterator is a ListIterator.

Pairwise

protected Pairwise(Iterator<T> it)

Constructor which does not assume the Iterator to be a ListIterator.

Method Details

first

public void first(T t)

Can be overridden by the user to visit the very first element before the first pair is visited by pairwise(Object,Object).

last

public void last(T t)

Can be overridden by the user to visit the very last element after the last pair is visited by pairwise(Object,Object).

pairwise

public abstract void pairwise(T t1,
 T t2)

Must be overridden by the user to visit the define what to do with each pair of adjacent elements. These are visited in the sequential order of the underlying Iterator. On Execution, that has berformed a Iterator.next(), so that it "points" (e.g. with its Iterator.hasNext() to the successor of the later of both visited elements.

process

public void process()

Central public service provision to visit all wlements in the order of the given (List-) Iterator, executing first(Object), pairwise(Object,Object), and last(Object) in this sequential order.