org.hypergraphdb.query.impl
Class UnionResult

java.lang.Object
  org.hypergraphdb.query.impl.UnionResult

All Implemented Interfaces:

java.util.Iterator, HGSearchResult, TwoWayIterator, CloseMe

public class UnionResult
extends java.lang.Object
implements HGSearchResult

Combines two result set into a result representing their set theoretic union. It is assumed that the input sets are ordered and hence that the objects contained therein are java.lang.Comparable instances.

The produced result set also has its elements in order.

Author:

Borislav Iordanov

Field Summary

Fields inherited from interface org.hypergraphdb.HGSearchResult

EMPTY

Constructor Summary

UnionResult(HGSearchResult left, HGSearchResult right)

Method Summary

void	close() Free all system resources held up by the result set and invalidate it for further use.
java.lang.Object	current() Returns the current element in the result set.
boolean	hasNext()
boolean	hasPrev() Return true if there is a previous element in the current iteration state and false otherwise.
boolean	isOrdered() Return true if the elements in this search result are in ordered and false otherwise.
java.lang.Object	next()
java.lang.Object	prev() Returns the previous element in this iteration.
void	remove()

Methods inherited from class java.lang.Object

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

Constructor Detail

UnionResult

public UnionResult(HGSearchResult left,
                   HGSearchResult right)

Method Detail

current

public java.lang.Object current()

Description copied from interface: HGSearchResult

Returns the current element in the result set. If there is no current element, java.util.NoSuchElementException is thrown. There is no current element in one of two cases: either the result set is empty or the next method was never invoked.

Specified by:

current in interface HGSearchResult

Returns:

The current element in a HGSearchResult.

close

public void close()

Description copied from interface: HGSearchResult

Free all system resources held up by the result set and invalidate it for further use.

Specified by:

close in interface HGSearchResult

Specified by:

close in interface CloseMe

prev

public java.lang.Object prev()

Description copied from interface: TwoWayIterator

Returns the previous element in this iteration.

Specified by:

prev in interface TwoWayIterator

hasPrev

public boolean hasPrev()

Description copied from interface: TwoWayIterator

Return true if there is a previous element in the current iteration state and false otherwise. After the iterator has been initialized, the value of hasPrev will always be false.

Specified by:

hasPrev in interface TwoWayIterator

hasNext

public boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator

next

public java.lang.Object next()

Specified by:

next in interface java.util.Iterator

remove

public void remove()

Specified by:

remove in interface java.util.Iterator

isOrdered

public boolean isOrdered()

Description copied from interface: HGSearchResult

Return true if the elements in this search result are in ordered and false otherwise. It is assumed that when elements are ordered, they are instances of java.lang.Comparable

Specified by:

isOrdered in interface HGSearchResult