org.plumelib.util

Class OrderedPairIterator<T>

java.lang.Object

org.plumelib.util.OrderedPairIterator<T>

Type Parameters:

T - the element type of the component iterator; this OrderedPairIterator has elements of type Pair<T,T>

All Implemented Interfaces:

java.util.Iterator<Pair<T,T>>

public class OrderedPairIterator<T>
extends java.lang.Object
implements java.util.Iterator<Pair<T,T>>

Given two sorted iterators, this class returns a new iterator that pairs equal elements of the inputs, according to the sort order or the given comparator. If an element has no equal element in the other iterator, then the element is paired with null.

For example, suppose that the inputs are

   [1, 2, 3, 5] and
   [1, 3, 5, 7, 9].
 

Then the output is

   [(1,1), (2,null), (3,3), (5,5), (null,7), (null, 9)].
 

(This operation is similar to, but not the same as, the operation called "zipping".)

In some cases this is just the right abstraction. But in some cases it's appropriate to use set intersection/difference instead.

Constructor Summary

Constructors

Constructor and Description
OrderedPairIterator(java.util.Iterator<T> itor1, java.util.Iterator<T> itor2) Create an iterator that returns pairs, where each pair contains has an element from each iterator and the two elements are equal.
OrderedPairIterator(java.util.Iterator<T> itor1, java.util.Iterator<T> itor2, java.util.Comparator<T> comparator) Create an iterator that returns pairs, where each pair contains has an element from each iterator and the two elements are equal according to the comparator.

Method Summary

Modifier and Type	Method and Description
boolean	hasNext()
Pair<T,T>	next()
void	remove()

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

Constructor Detail

OrderedPairIterator

public OrderedPairIterator(java.util.Iterator<T> itor1,
                           java.util.Iterator<T> itor2)

Create an iterator that returns pairs, where each pair contains has an element from each iterator and the two elements are equal.

Parameters:

itor1 - iterator for first elements of pairs

itor2 - iterator for second elements of pairs

OrderedPairIterator

public OrderedPairIterator(java.util.Iterator<T> itor1,
                           java.util.Iterator<T> itor2,
                           java.util.Comparator<T> comparator)

Create an iterator that returns pairs, where each pair contains has an element from each iterator and the two elements are equal according to the comparator.

Parameters:

itor1 - iterator for first elements of pairs

itor2 - iterator for second elements of pairs

comparator - determines whether two elements are equal and should be paired together

Method Detail

hasNext

public boolean hasNext(@GuardSatisfied OrderedPairIterator<T> this)

Specified by:

hasNext in interface java.util.Iterator<Pair<T,T>>

next

public Pair<T,T> next(@GuardSatisfied OrderedPairIterator<T> this)

Specified by:

next in interface java.util.Iterator<Pair<T,T>>

remove

public void remove(@GuardSatisfied OrderedPairIterator<T> this)

Specified by:

remove in interface java.util.Iterator<Pair<T,T>>