QPatternist::IntersectIterator Class Reference

Implements the intersect operator. That is, the computation of the intersection between two sequences of nodes. More...

#include <qintersectiterator_p.h>

Inheritance diagram for QPatternist::IntersectIterator:

Public Functions
virtual Item::Iterator::Ptr	copy () const
	Copies this QAbstractXmlForwardIterator and returns the copy. More...
virtual Item	current () const
	Returns the current item in the sequence. More...
	IntersectIterator (const Item::Iterator::Ptr &it1, const Item::Iterator::Ptr &it2)
virtual Item	next ()
	Returns the next item in the sequence, or a null object if the end has been reached. More...
virtual xsInteger	position () const
	Returns the current position in the sequence represented by this. More...
Public Functions inherited from QAbstractXmlForwardIterator< Item >
virtual qint64	count ()
	Determines the number of items this QAbstractXmlForwardIterator represents. More...
virtual bool	isEmpty ()
	Returns true if the sequence is empty. More...
virtual Item	last ()
	Returns the item at the end of this QAbstractXmlForwardIterator. More...
	QAbstractXmlForwardIterator ()
	Default constructor. More...
virtual qint64	sizeHint () const
	Gives a hint to the size of the contained sequence. More...
virtual QList< Item >	toList ()
	Performs a copy of this QAbstractXmlForwardIterator(with copy()), and returns its items in a QList. More...
virtual QAbstractXmlForwardIterator< Item >::Ptr	toReversed ()
	Returns a reverse iterator for the sequence. More...
virtual	~QAbstractXmlForwardIterator ()
	Destructor. More...
Public Functions inherited from QSharedData
	QSharedData ()
	Constructs a QSharedData object with a reference count of 0. More...
	QSharedData (const QSharedData &)
	Constructs a QSharedData object with reference count 0. More...

Private Functions
Item	closedExit ()

Properties
Item	m_current
const Item::Iterator::Ptr	m_it1
const Item::Iterator::Ptr	m_it2
Item	m_node1
Item	m_node2
xsInteger	m_position

Additional Inherited Members
Public Types inherited from QAbstractXmlForwardIterator< Item >
typedef QList< QExplicitlySharedDataPointer< QAbstractXmlForwardIterator< Item > > >	List
	A QList containing QAbstractXmlForwardIterator::Ptr instances. More...
typedef QExplicitlySharedDataPointer< QAbstractXmlForwardIterator< Item > >	Ptr
	A smart pointer wrapping an instance of a QAbstractXmlForwardIterator subclass. More...
typedef QVector< QExplicitlySharedDataPointer< QAbstractXmlForwardIterator< Item > > >	Vector
	A QVector containing QAbstractXmlForwardIterator::Ptr instances. More...
Public Variables inherited from QSharedData
QAtomicInt	ref
Related Functions inherited from QAbstractXmlForwardIterator< Item >
static QAbstractXmlForwardIterator< TResult >::Ptr	makeSequenceMappingIterator (const TMapper &mapper, const QExplicitlySharedDataPointer< QAbstractXmlForwardIterator< TSource > > &source, const DynamicContext::Ptr &context)
	An object generator for SequenceMappingIterator. More...
bool	qIsForwardIteratorEnd (const Item &unit)
	The Callback QAbstractXmlForwardIterator uses for determining whether unit is the end of a sequence. More...

Detailed Description

Implements the intersect operator. That is, the computation of the intersection between two sequences of nodes.

The intersect operator can be seen as logical AND of the two sets.

Definition at line 71 of file qintersectiterator_p.h.

Constructors and Destructors

IntersectIterator()

IntersectIterator::IntersectIterator	(	const Item::Iterator::Ptr &	it1,
		const Item::Iterator::Ptr &	it2
	)

It is assumed that it1 and it2 are in document order and without duplicates.

Definition at line 50 of file qintersectiterator.cpp.

Referenced by copy().

                                                                 : m_it1(it1),
                                                                       m_it2(it2),
                                                                       m_position(0),
                                                                       m_node1(m_it1->next()),
                                                                       m_node2(m_it2->next())
{
    Q_ASSERT(m_it1);
    Q_ASSERT(m_it2);
}

Functions

closedExit()

Item QPatternist::IntersectIterator::closedExit ( )

inlineprivate

Definition at line 87 of file qintersectiterator_p.h.

Referenced by next().

        {
            m_position = -1;
            m_current = Item();
            return Item();
        }

copy()

Item::Iterator::Ptr IntersectIterator::copy ( ) const

virtual

Copies this QAbstractXmlForwardIterator and returns the copy.

Warning

This function is not part of the public interface.

A copy and the original instance are completely independent of each other. Because evaluating an QAbstractXmlForwardIterator modifies it, one should always use a copy when an QAbstractXmlForwardIterator needs to be used several times.

Reimplemented from QAbstractXmlForwardIterator< Item >.

Definition at line 110 of file qintersectiterator.cpp.

{
    return Item::Iterator::Ptr(new IntersectIterator(m_it1->copy(), m_it2->copy()));
}

current()

Item IntersectIterator::current ( ) const

virtual

Returns the current item in the sequence.

If this function is called before the first call to next(), a null object is returned. If the end of the sequence has been reached, a null object is returned.

Implements QAbstractXmlForwardIterator< Item >.

Definition at line 100 of file qintersectiterator.cpp.

{
    return m_current;
}

next()

Item IntersectIterator::next ( )

virtual

Returns the next item in the sequence, or a null object if the end has been reached.

Implements QAbstractXmlForwardIterator< Item >.

Definition at line 61 of file qintersectiterator.cpp.

{
    if(!m_node1 || !m_node2)
        return closedExit();

    do
    {
        if(m_node1.asNode().model() == m_node2.asNode().model())
        {
            switch(m_node1.asNode().compareOrder(m_node2.asNode()))
            {
                case QXmlNodeModelIndex::Precedes:
                {
                    m_node1 = m_it1->next();
                    break;
                }
                case QXmlNodeModelIndex::Follows:
                {
                    m_node2 = m_it2->next();
                    break;
                }
                default:
                {
                    m_current = m_node2;
                    m_node1 = m_it1->next();
                    m_node2 = m_it2->next();
                    ++m_position;
                    return m_current;
                }
            }
        }
        else
            m_node2 = m_it2->next();
    }
    while(m_node1 && m_node2);

    return Item();
}

position()

xsInteger IntersectIterator::position ( ) const

virtual

Returns the current position in the sequence represented by this.

The first position is 1, not 0. If next() hasn't been called, 0 is returned. If this has reached the end, -1 is returned.

Implements QAbstractXmlForwardIterator< Item >.

Definition at line 105 of file qintersectiterator.cpp.

{
    return m_position;
}

Properties

m_current

Item QPatternist::IntersectIterator::m_current

private

Definition at line 96 of file qintersectiterator_p.h.

Referenced by closedExit(), current(), and next().

m_it1

const Item::Iterator::Ptr QPatternist::IntersectIterator::m_it1

private

Definition at line 94 of file qintersectiterator_p.h.

Referenced by copy(), IntersectIterator(), and next().

m_it2

const Item::Iterator::Ptr QPatternist::IntersectIterator::m_it2

private

Definition at line 95 of file qintersectiterator_p.h.

Referenced by copy(), IntersectIterator(), and next().

m_node1

Item QPatternist::IntersectIterator::m_node1

private

Definition at line 98 of file qintersectiterator_p.h.

Referenced by next().

m_node2

Item QPatternist::IntersectIterator::m_node2

private

Definition at line 99 of file qintersectiterator_p.h.

Referenced by next().

m_position

xsInteger QPatternist::IntersectIterator::m_position

private

Definition at line 97 of file qintersectiterator_p.h.

Referenced by closedExit(), next(), and position().

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The documentation for this class was generated from the following files:

• /src/xmlpatterns/iterators/qintersectiterator_p.h
• /src/xmlpatterns/iterators/qintersectiterator.cpp