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39
40#include "qxpathhelper_p.h"
41
42#include "qsubsequenceiterator_p.h"
43
44QT_BEGIN_NAMESPACE
45
46using namespace QPatternist;
47
48SubsequenceIterator::SubsequenceIterator(const Item::Iterator::Ptr &iterator,
49 const xsInteger start,
50 const xsInteger len)
51 : m_position(0),
52 m_it(iterator),
53 m_counter(start),
54 m_start(start),
55 m_len(len),
56 m_stop(m_start + m_len)
57{
58 Q_ASSERT(iterator);
59 Q_ASSERT(start >= 1);
60 Q_ASSERT(len == -1 || len >= 1);
61
62 /* Note, "The first item of a sequence is located at position 1, not position 0." */
63 for(xsInteger i = 1; i != m_start; ++i)
64 m_it->next();
65}
66
67Item SubsequenceIterator::next()
68{
69 if(m_position == -1)
70 return Item();
71
72 m_current = m_it->next();
73 ++m_position;
74
75 if(m_len == -1)
76 {
77 if(!m_current)
78 m_position = -1;
79
80 return m_current;
81 }
82
83 ++m_counter;
84
85 if(!(m_counter > m_stop) && m_current)
86 return m_current;
87
88 m_position = -1;
89 m_current.reset();
90 return Item();
91}
92
93Item SubsequenceIterator::current() const
94{
95 return m_current;
96}
97
98xsInteger SubsequenceIterator::position() const
99{
100 return m_position;
101}
102
103Item::Iterator::Ptr SubsequenceIterator::copy() const
104{
105 return Item::Iterator::Ptr(new SubsequenceIterator(m_it->copy(), m_start, m_len));
106}
107
108QT_END_NAMESPACE
109

source code of qtxmlpatterns/src/xmlpatterns/iterators/qsubsequenceiterator.cpp