summaryrefslogtreecommitdiffstats
path: root/src/xmlpatterns/expr/qvaluecomparison.cpp
blob: 36520e295c59ec2a8c873d22dee8b01a1aeb1dcf (plain)
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
/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** 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 1.1, 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 have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qitem_p.h"
#include "qboolean_p.h"
#include "qbuiltintypes_p.h"
#include "qcommonsequencetypes_p.h"
#include "qemptysequence_p.h"
#include "qoptimizationpasses_p.h"

#include "qvaluecomparison_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

ValueComparison::ValueComparison(const Expression::Ptr &op1,
                                 const AtomicComparator::Operator op,
                                 const Expression::Ptr &op2) : PairContainer(op1, op2),
                                                               m_operator(op)
{
}

Item ValueComparison::evaluateSingleton(const DynamicContext::Ptr &context) const
{
    const Item it1(m_operand1->evaluateSingleton(context));
    if(!it1)
        return Item();

    const Item it2(m_operand2->evaluateSingleton(context));
    if(!it2)
        return Item();

    return Boolean::fromValue(flexibleCompare(it1, it2, context));
}

Expression::Ptr ValueComparison::typeCheck(const StaticContext::Ptr &context,
                                           const SequenceType::Ptr &reqType)
{
    const Expression::Ptr me(PairContainer::typeCheck(context, reqType));
    const ItemType::Ptr t1(m_operand1->staticType()->itemType());
    const ItemType::Ptr t2(m_operand2->staticType()->itemType());
    Q_ASSERT(t1);
    Q_ASSERT(t2);

    if(*CommonSequenceTypes::Empty == *t1 ||
       *CommonSequenceTypes::Empty == *t2)
    {
        return EmptySequence::create(this, context);
    }
    else
    {
        prepareComparison(fetchComparator(t1, t2, context));

        return me;
    }
}

Expression::Ptr ValueComparison::compress(const StaticContext::Ptr &context)
{
    const Expression::Ptr me(PairContainer::compress(context));

    if(me != this)
        return me;

    if(isCaseInsensitiveCompare(m_operand1, m_operand2))
        useCaseInsensitiveComparator();

    return me;
}

bool ValueComparison::isCaseInsensitiveCompare(Expression::Ptr &op1, Expression::Ptr &op2)
{
    Q_ASSERT(op1);
    Q_ASSERT(op2);

    const ID iD = op1->id();

    if((iD == IDLowerCaseFN || iD == IDUpperCaseFN) && iD == op2->id())
    {
        /* Both are either fn:lower-case() or fn:upper-case(). */

        /* Replace the calls to the functions with its operands. */
        op1 = op1->operands().first();
        op2 = op2->operands().first();

        return true;
    }
    else
        return false;
}

OptimizationPass::List ValueComparison::optimizationPasses() const
{
    return OptimizationPasses::comparisonPasses;
}

SequenceType::List ValueComparison::expectedOperandTypes() const
{
    SequenceType::List result;
    result.append(CommonSequenceTypes::ZeroOrOneAtomicType);
    result.append(CommonSequenceTypes::ZeroOrOneAtomicType);
    return result;
}

SequenceType::Ptr ValueComparison::staticType() const
{
    if(m_operand1->staticType()->cardinality().allowsEmpty() ||
       m_operand2->staticType()->cardinality().allowsEmpty())
        return CommonSequenceTypes::ZeroOrOneBoolean;
    else
        return CommonSequenceTypes::ExactlyOneBoolean;
}

ExpressionVisitorResult::Ptr ValueComparison::accept(const ExpressionVisitor::Ptr &visitor) const
{
    return visitor->visit(this);
}

Expression::ID ValueComparison::id() const
{
    return IDValueComparison;
}

QT_END_NAMESPACE