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46 // This file is not part of the Qt API. It exists purely as an
47 // implementation detail. This header file may change from version to
48 // version without notice, or even be removed.
52 #ifndef Patternist_SingletonIterator_H
53 #define Patternist_SingletonIterator_H
55 #include <QtXmlPatterns/private/qabstractxmlforwarditerator_p.h>
57 #include <QtXmlPatterns/private/qprimitives_p.h>
66 * @short An QAbstractXmlForwardIterator over exactly one item.
68 * SingletonIterator's constructor takes one value which is
69 * the item it forms an QAbstractXmlForwardIterator over. Other QAbstractXmlForwardIterator instances can
70 * also form an QAbstractXmlForwardIterator with one in length, but by that SingletonIterator
71 * has this as it only task, it means it is efficient at it.
73 * Having to represent single items in Iterators is relatively common.
75 * @author Frans Englich <frans.englich@nokia.com>
76 * @ingroup Patternist_iterators
79 class SingletonIterator : public QAbstractXmlForwardIterator<T>
83 * Creates an iterator over @p item.
85 * @note item may not be @c null. Use the EmptyIterator for
88 SingletonIterator(const T &item) : m_item(item),
91 Q_ASSERT(!qIsForwardIteratorEnd(item));
110 Q_ASSERT(m_position == -1);
116 virtual T current() const
124 virtual xsInteger position() const
130 * @returns a copy of this instance, rewinded to the beginning.
132 virtual typename QAbstractXmlForwardIterator<T>::Ptr toReversed()
134 return typename QAbstractXmlForwardIterator<T>::Ptr(new SingletonIterator<T>(m_item));
140 virtual xsInteger count()
145 virtual typename QAbstractXmlForwardIterator<T>::Ptr copy() const
147 return typename QAbstractXmlForwardIterator<T>::Ptr(new SingletonIterator(m_item));
156 * @short An object generator for SingletonIterator.
158 * makeSingletonIterator() is a convenience function for avoiding specifying
159 * the full template instantiation for SingletonIterator. Conceptually, it
160 * is identical to Qt's qMakePair().
162 * @relates SingletonIterator
166 typename SingletonIterator<T>::Ptr
167 makeSingletonIterator(const T &item)
169 return typename SingletonIterator<T>::Ptr(new SingletonIterator<T>(item));