Package com.usatiuk.objects.iterators

Class ReversedKvIterator<K extends Comparable<? super K>,V>

java.lang.Object

com.usatiuk.objects.iterators.ReversedKvIterator<K,V>

Type Parameters:

K - the type of the keys

V - the type of the values

All Implemented Interfaces:

CloseableKvIterator<K,V>, AutoCloseable, Iterator<org.apache.commons.lang3.tuple.Pair<K,V>>

public class ReversedKvIterator<K extends Comparable<? super K>,V>
extends Object
implements CloseableKvIterator<K,V>

A wrapper for a key-value iterator that iterates in reverse order.

Constructor Summary

Constructors

Constructor	Description
ReversedKvIterator(CloseableKvIterator<K,V> backing)	Constructs a ReversedKvIterator with the specified backing iterator.

Method Summary

Modifier and Type	Method	Description
void	close()
boolean	hasNext()
boolean	hasPrev()	Checks if there is a previous element in the reverse direction.
org.apache.commons.lang3.tuple.Pair<K,V>	next()
K	peekNextKey()	Returns the upcoming key in the forward direction without advancing the iterator.
K	peekPrevKey()	Checks if there is a next element in the forward direction.
org.apache.commons.lang3.tuple.Pair<K,V>	prev()	Returns the key-value pair in the reverse direction, and advances the iterator.
CloseableKvIterator<K,V>	reversed()	Returns a reversed iterator that iterates in the reverse direction.
void	skip()	Skips the next element in the forward direction.
void	skipPrev()	Skips the previous element in the reverse direction.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Details

ReversedKvIterator

public ReversedKvIterator(CloseableKvIterator<K,V> backing)

Constructs a ReversedKvIterator with the specified backing iterator.

Parameters:

backing - the backing iterator

Method Details

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface CloseableKvIterator<K extends Comparable<? super K>,V>

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<K extends Comparable<? super K>>

next

public org.apache.commons.lang3.tuple.Pair<K,V> next()

Specified by:

next in interface Iterator<K extends Comparable<? super K>>

peekNextKey

public K peekNextKey()

Description copied from interface: CloseableKvIterator

Returns the upcoming key in the forward direction without advancing the iterator.

Specified by:

peekNextKey in interface CloseableKvIterator<K extends Comparable<? super K>,V>

Returns:

the current key

skip

public void skip()

Description copied from interface: CloseableKvIterator

Skips the next element in the forward direction.

Specified by:

skip in interface CloseableKvIterator<K extends Comparable<? super K>,V>

peekPrevKey

public K peekPrevKey()

Description copied from interface: CloseableKvIterator

Checks if there is a next element in the forward direction.

Specified by:

peekPrevKey in interface CloseableKvIterator<K extends Comparable<? super K>,V>

Returns:

true if there is a next element, false otherwise

prev

public org.apache.commons.lang3.tuple.Pair<K,V> prev()

Description copied from interface: CloseableKvIterator

Returns the key-value pair in the reverse direction, and advances the iterator.

Specified by:

prev in interface CloseableKvIterator<K extends Comparable<? super K>,V>

Returns:

the previous key-value pair

hasPrev

public boolean hasPrev()

Description copied from interface: CloseableKvIterator

Checks if there is a previous element in the reverse direction.

Specified by:

hasPrev in interface CloseableKvIterator<K extends Comparable<? super K>,V>

Returns:

true if there is a previous element, false otherwise

skipPrev

public void skipPrev()

Description copied from interface: CloseableKvIterator

Skips the previous element in the reverse direction.

Specified by:

skipPrev in interface CloseableKvIterator<K extends Comparable<? super K>,V>

reversed

public CloseableKvIterator<K,V> reversed()

Description copied from interface: CloseableKvIterator

Returns a reversed iterator that iterates in the reverse direction.

Specified by:

reversed in interface CloseableKvIterator<K extends Comparable<? super K>,V>

Returns:

a new CloseableKvIterator that iterates in the reverse direction