Qt 4.8
qoperandsiterator_p.h
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41 
42 //
43 // W A R N I N G
44 // -------------
45 //
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.
49 //
50 // We mean it.
51 
52 #ifndef Patternist_OperandsIterator_H
53 #define Patternist_OperandsIterator_H
54 
55 #include <QPair>
56 #include <QStack>
57 
58 #include "qexpression_p.h"
59 
61 
63 
64 namespace QPatternist
65 {
78  {
83 
84  public:
86  {
89  };
90 
96  inline OperandsIterator(const Expression::Ptr &start,
97  const TreatParent treatParent)
98  {
99  Q_ASSERT(start);
100  if(treatParent == IncludeParent)
101  {
103  l.append(start);
104  m_exprs.push(qMakePair(l, -1));
105  }
106 
107  m_exprs.push(qMakePair(start->operands(), -1));
108  }
109 
119  {
120  if(m_exprs.isEmpty())
121  return Expression::Ptr();
122 
123  Level &lvl = m_exprs.top();
124  ++lvl.second;
125 
126  if(lvl.second == lvl.first.size())
127  {
128  /* Resume iteration above us. */
129  m_exprs.pop();
130 
131  if(m_exprs.isEmpty())
132  return Expression::Ptr();
133 
134  while(true)
135  {
136  Level &previous = m_exprs.top();
137  ++previous.second;
138 
139  if(previous.second < previous.first.count())
140  {
141  const Expression::Ptr &op = previous.first.at(previous.second);
142  m_exprs.push(qMakePair(op->operands(), -1));
143  return op;
144  }
145  else
146  {
147  // We have already reached the end of this level.
148  m_exprs.pop();
149  if(m_exprs.isEmpty())
150  return Expression::Ptr();
151  }
152  }
153  }
154  else
155  {
156  const Expression::Ptr &op = lvl.first.at(lvl.second);
157  m_exprs.push(qMakePair(op->operands(), -1));
158  return op;
159  }
160  }
161 
166  {
167  if(m_exprs.isEmpty())
168  return Expression::Ptr();
169 
170  Level &lvl = m_exprs.top();
171  ++lvl.second;
172 
173  if(lvl.second == lvl.first.size())
174  {
175  /* We've reached the end of this level, at least. */
176  m_exprs.pop();
177  }
178 
179  return next();
180  }
181 
182  private:
184 
185  QStack<Level> m_exprs;
186  };
187 }
188 
189 
192 
193 #endif
#define QT_END_NAMESPACE
This macro expands to.
Definition: qglobal.h:90
#define QT_BEGIN_HEADER
Definition: qglobal.h:136
T1 first
Definition: qpair.h:65
T2 second
Definition: qpair.h:66
OperandsIterator(const Expression::Ptr &start, const TreatParent treatParent)
#define Q_DISABLE_COPY(Class)
Disables the use of copy constructors and assignment operators for the given Class.
Definition: qglobal.h:2523
The QStack class is a template class that provides a stack.
Definition: qcontainerfwd.h:63
#define Q_ASSERT(cond)
Definition: qglobal.h:1823
Expression::Ptr next()
Returns the current Expression and advances the iterator.
QPair< Expression::List, int > Level
void append(const T &t)
Inserts value at the end of the list.
Definition: qlist.h:507
#define QT_BEGIN_NAMESPACE
This macro expands to.
Definition: qglobal.h:89
The namespace for the internal API of QtXmlPatterns.
Q_OUTOFLINE_TEMPLATE QPair< T1, T2 > qMakePair(const T1 &x, const T2 &y)
Definition: qpair.h:102
QFactoryLoader * l
#define QT_END_HEADER
Definition: qglobal.h:137
A helper class that iterates a tree of Expression instances. It is not a sub-class of QAbstractXmlFor...