1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (qt-info@nokia.com)
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at qt-sales@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qcommonsequencetypes_p.h"
#include "qexceptiterator_p.h"
#include "qgenericsequencetype_p.h"
#include "qintersectiterator_p.h"
#include "qitemmappingiterator_p.h"
#include "qnodesort_p.h"
#include "qunioniterator_p.h"
#include "qcombinenodes_p.h"
QT_BEGIN_NAMESPACE
using namespace QPatternist;
CombineNodes::CombineNodes(const Expression::Ptr &operand1,
const Operator op,
const Expression::Ptr &operand2) : PairContainer(operand1, operand2),
m_operator(op)
{
Q_ASSERT(op == Union ||
op == Except ||
op == Intersect);
}
Item::Iterator::Ptr CombineNodes::evaluateSequence(const DynamicContext::Ptr &context) const
{
const Item::Iterator::Ptr op1(m_operand1->evaluateSequence(context));
const Item::Iterator::Ptr op2(m_operand2->evaluateSequence(context));
switch(m_operator)
{
case Intersect:
return Item::Iterator::Ptr(new IntersectIterator(op1, op2));
case Except:
return Item::Iterator::Ptr(new ExceptIterator(op1, op2));
default:
{
Q_ASSERT(m_operator == Union);
return Item::Iterator::Ptr(new UnionIterator(op1, op2));
}
}
}
Item CombineNodes::evaluateSingleton(const DynamicContext::Ptr &context) const
{
return evaluateSequence(context)->next();
}
Expression::Ptr CombineNodes::typeCheck(const StaticContext::Ptr &context,
const SequenceType::Ptr &reqType)
{
const Expression::Ptr me(PairContainer::typeCheck(context, reqType));
m_operand1 = NodeSortExpression::wrapAround(m_operand1, context);
m_operand2 = NodeSortExpression::wrapAround(m_operand2, context);
return me;
}
bool CombineNodes::evaluateEBV(const DynamicContext::Ptr &context) const
{
/* If it's the union operator, we can possibly avoid
* evaluating the second operand. */
if(m_operator == Union)
{
return m_operand1->evaluateEBV(context) ||
m_operand2->evaluateEBV(context);
}
else
return PairContainer::evaluateEBV(context);
}
QString CombineNodes::displayName(const Operator op)
{
switch(op)
{
case Intersect:
return QLatin1String("intersect");
case Except:
return QLatin1String("except");
default:
{
Q_ASSERT(op == Union);
return QLatin1String("union");
}
}
}
SequenceType::Ptr CombineNodes::staticType() const
{
const SequenceType::Ptr t1(m_operand1->staticType());
const SequenceType::Ptr t2(m_operand2->staticType());
Cardinality card;
/* Optimization: the cardinality can be better inferred for
* Intersect and Except, although it's not trivial code. */
if(m_operator == Union)
card = t1->cardinality() | t2->cardinality();
else /* Except. */
card = Cardinality::zeroOrMore();
return makeGenericSequenceType(t1->itemType() | t2->itemType(), card);
}
SequenceType::List CombineNodes::expectedOperandTypes() const
{
SequenceType::List result;
result.append(CommonSequenceTypes::ZeroOrMoreNodes);
result.append(CommonSequenceTypes::ZeroOrMoreNodes);
return result;
}
CombineNodes::Operator CombineNodes::operatorID() const
{
return m_operator;
}
ExpressionVisitorResult::Ptr CombineNodes::accept(const ExpressionVisitor::Ptr &visitor) const
{
return visitor->visit(this);
}
Expression::ID CombineNodes::id() const
{
return IDCombineNodes;
}
QT_END_NAMESPACE
|
