ca.uqac.dim.turtledb

Class Union.UnionStreamIterator

java.lang.Object

ca.uqac.dim.turtledb.RelationStreamIterator

ca.uqac.dim.turtledb.NAryRelation.NAryRelationStreamIterator

ca.uqac.dim.turtledb.Union.UnionStreamIterator

All Implemented Interfaces:

RelationIterator, java.util.Iterator<Tuple>

Enclosing class:

Union

protected class Union.UnionStreamIterator
extends NAryRelation.NAryRelationStreamIterator

Field Summary

Fields inherited from class ca.uqac.dim.turtledb.NAryRelation.NAryRelationStreamIterator

m_first, m_iterators, m_lastTuple

Fields inherited from class ca.uqac.dim.turtledb.RelationStreamIterator

m_internalNextCalled, m_nextTuple, m_outputTuples

Constructor Summary

Constructors

Constructor and Description
UnionStreamIterator()

Method Summary

Modifier and Type	Method and Description
protected Tuple	internalNext() Method that must be implemented by every non-abstract relation; it returns the next tuple of the enumeration, if any.

Methods inherited from class ca.uqac.dim.turtledb.NAryRelation.NAryRelationStreamIterator

incrementSmallestTuple, initializeIteration, reset

Methods inherited from class ca.uqac.dim.turtledb.RelationStreamIterator

hasNext, next, 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

UnionStreamIterator

public UnionStreamIterator()

Method Detail

internalNext

protected Tuple internalNext()

Description copied from class: RelationStreamIterator

Method that must be implemented by every non-abstract relation; it returns the next tuple of the enumeration, if any. Methods next and hasNext use the return value of internalNext and additionally remove any duplicate tuples from the output enumeration. Hence a call to next may result in multiple calls to the relation's internalNext, if the tuples returned are already part of the result (this is especially true of Projections.

Specified by:

internalNext in class RelationStreamIterator

Returns:

The next tuple, null if no such tuple exists