[2] | 1 | /****************************************************************************
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| 2 | **
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| 3 | ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
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[561] | 4 | ** All rights reserved.
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| 5 | ** Contact: Nokia Corporation ([email protected])
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[2] | 6 | **
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| 7 | ** This file is part of the QtXmlPatterns module of the Qt Toolkit.
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| 8 | **
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| 9 | ** $QT_BEGIN_LICENSE:LGPL$
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| 10 | ** Commercial Usage
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| 11 | ** Licensees holding valid Qt Commercial licenses may use this file in
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| 12 | ** accordance with the Qt Commercial License Agreement provided with the
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| 13 | ** Software or, alternatively, in accordance with the terms contained in
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| 14 | ** a written agreement between you and Nokia.
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| 15 | **
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| 16 | ** GNU Lesser General Public License Usage
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| 17 | ** Alternatively, this file may be used under the terms of the GNU Lesser
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| 18 | ** General Public License version 2.1 as published by the Free Software
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| 19 | ** Foundation and appearing in the file LICENSE.LGPL included in the
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| 20 | ** packaging of this file. Please review the following information to
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| 21 | ** ensure the GNU Lesser General Public License version 2.1 requirements
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| 22 | ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
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| 23 | **
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[561] | 24 | ** In addition, as a special exception, Nokia gives you certain additional
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| 25 | ** rights. These rights are described in the Nokia Qt LGPL Exception
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| 26 | ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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[2] | 27 | **
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| 28 | ** GNU General Public License Usage
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| 29 | ** Alternatively, this file may be used under the terms of the GNU
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| 30 | ** General Public License version 3.0 as published by the Free Software
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| 31 | ** Foundation and appearing in the file LICENSE.GPL included in the
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| 32 | ** packaging of this file. Please review the following information to
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| 33 | ** ensure the GNU General Public License version 3.0 requirements will be
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| 34 | ** met: http://www.gnu.org/copyleft/gpl.html.
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| 35 | **
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[561] | 36 | ** If you have questions regarding the use of this file, please contact
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| 37 | ** Nokia at [email protected].
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[2] | 38 | ** $QT_END_LICENSE$
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| 39 | **
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| 40 | ****************************************************************************/
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| 41 |
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| 42 | #include "qboolean_p.h"
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| 43 | #include "qcommonsequencetypes_p.h"
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| 44 | #include "qdynamiccontextstore_p.h"
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| 45 | #include "qliteral_p.h"
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| 46 |
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| 47 | #include "qletclause_p.h"
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| 48 |
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| 49 | QT_BEGIN_NAMESPACE
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| 50 |
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| 51 | using namespace QPatternist;
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| 52 |
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| 53 | LetClause::LetClause(const Expression::Ptr &operand1,
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| 54 | const Expression::Ptr &operand2,
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| 55 | const VariableDeclaration::Ptr &decl) : PairContainer(operand1, operand2)
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| 56 | , m_varDecl(decl)
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| 57 | {
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| 58 | Q_ASSERT(m_varDecl);
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| 59 | }
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| 60 |
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| 61 | DynamicContext::Ptr LetClause::bindVariable(const DynamicContext::Ptr &context) const
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| 62 | {
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| 63 | context->setExpressionVariable(m_varDecl->slot, Expression::Ptr(new DynamicContextStore(m_operand1, context)));
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| 64 | return context;
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| 65 | }
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| 66 |
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| 67 | Item::Iterator::Ptr LetClause::evaluateSequence(const DynamicContext::Ptr &context) const
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| 68 | {
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| 69 | return m_operand2->evaluateSequence(bindVariable(context));
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| 70 | }
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| 71 |
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| 72 | Item LetClause::evaluateSingleton(const DynamicContext::Ptr &context) const
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| 73 | {
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| 74 | return m_operand2->evaluateSingleton(bindVariable(context));
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| 75 | }
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| 76 |
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| 77 | bool LetClause::evaluateEBV(const DynamicContext::Ptr &context) const
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| 78 | {
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| 79 | return m_operand2->evaluateEBV(bindVariable(context));
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| 80 | }
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| 81 |
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| 82 | void LetClause::evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const
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| 83 | {
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| 84 | m_operand2->evaluateToSequenceReceiver(bindVariable(context));
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| 85 | }
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| 86 |
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| 87 | Expression::Ptr LetClause::typeCheck(const StaticContext::Ptr &context,
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| 88 | const SequenceType::Ptr &reqType)
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| 89 | {
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| 90 | /* Consider the following query:
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| 91 | *
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| 92 | * <tt>let $d := \<child type=""/>
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| 93 | * return $d//\*[let $i := @type
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| 94 | * return $d//\*[$i]]</tt>
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| 95 | *
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| 96 | * The node test <tt>@type</tt> is referenced from two different places,
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| 97 | * where each reference have a different focus. So, in the case of that the source
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| 98 | * uses the focus, we need to use a DynamicContextStore to ensure the variable
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| 99 | * is always evaluated with the correct focus, regardless of where it is referenced
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| 100 | * from.
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| 101 | *
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| 102 | * We miss out a lot of false positives. For instance, the case of where the focus
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| 103 | * is identical for everyone. One reason we cannot check this, is that Expression
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| 104 | * doesn't know about its parent.
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| 105 | */
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| 106 | m_varDecl->canSourceRewrite = !m_operand1->deepProperties().testFlag(RequiresFocus);
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| 107 |
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| 108 | if(m_varDecl->canSourceRewrite)
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| 109 | return m_operand2->typeCheck(context, reqType);
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| 110 | else
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| 111 | return PairContainer::typeCheck(context, reqType);
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| 112 | }
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| 113 |
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| 114 | Expression::Properties LetClause::properties() const
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| 115 | {
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| 116 | return m_varDecl->expression()->properties() & (Expression::RequiresFocus | Expression::IsEvaluated | Expression::DisableElimination);
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| 117 | }
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| 118 |
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| 119 | SequenceType::List LetClause::expectedOperandTypes() const
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| 120 | {
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| 121 | SequenceType::List result;
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| 122 | result.append(CommonSequenceTypes::ZeroOrMoreItems);
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| 123 | result.append(CommonSequenceTypes::ZeroOrMoreItems);
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| 124 | return result;
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| 125 | }
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| 126 |
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| 127 | SequenceType::Ptr LetClause::staticType() const
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| 128 | {
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| 129 | return m_operand2->staticType();
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| 130 | }
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| 131 |
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| 132 | ExpressionVisitorResult::Ptr LetClause::accept(const ExpressionVisitor::Ptr &visitor) const
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| 133 | {
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| 134 | return visitor->visit(this);
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| 135 | }
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| 136 |
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| 137 | Expression::ID LetClause::id() const
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| 138 | {
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| 139 | return IDLetClause;
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| 140 | }
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| 141 |
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| 142 | QT_END_NAMESPACE
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