Long live Qt!

1 files changed, 297 insertions, 0 deletions

diff --git a/src/xmlpatterns/expr/qgeneralcomparison.cpp b/src/xmlpatterns/expr/qgeneralcomparison.cpp
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+/****************************************************************************
+**
+** 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 "qbuiltintypes_p.h"
+#include "qcommonsequencetypes_p.h"
+#include "qcommonvalues_p.h"
+#include "qebvextractor_p.h"
+#include "qitem_p.h"
+#include "qliteral_p.h"
+#include "qoptimizationpasses_p.h"
+#include "quntypedatomicconverter_p.h"
+#include "qvaluecomparison_p.h"
+
+#include "qgeneralcomparison_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+GeneralComparison::GeneralComparison(const Expression::Ptr &op1,
+                                     const AtomicComparator::Operator op,
+                                     const Expression::Ptr &op2,
+                                     const bool isBackwardsCompat) : PairContainer(op1, op2)
+                                                                   , m_operator(op)
+                                                                   , m_isBackwardsCompat(isBackwardsCompat)
+{
+}
+
+bool GeneralComparison::generalCompare(const Item &op1,
+                                       const Item &op2,
+                                       const DynamicContext::Ptr &context) const
+{
+    Q_ASSERT(op1);
+    Q_ASSERT(op2);
+
+    if(comparator())
+        return compare(op1, op2, comparator(), m_operator);
+
+    Expression::Ptr a1(new Literal(op1));
+    Expression::Ptr a2(new Literal(op2));
+
+    const AtomicComparator::Ptr comp(fetchGeneralComparator(a1, a2, context));
+    /* The fetchGeneralComparator call may rewrite a1 and/or a2. */
+    Q_ASSERT(a1);
+    Q_ASSERT(a2);
+    Q_ASSERT(comp);
+
+    return compare(a1->evaluateSingleton(context),
+                   a2->evaluateSingleton(context),
+                   comp,
+                   m_operator);
+}
+
+bool GeneralComparison::evaluateEBV(const DynamicContext::Ptr &context) const
+{
+    const Item::Iterator::Ptr it1(m_operand1->evaluateSequence(context));
+    Item item1(it1->next());
+
+    if(!item1)
+        return false;
+
+    const Item::Iterator::Ptr it2(m_operand2->evaluateSequence(context));
+    Item::List cache;
+    Item item2;
+
+    while(true)
+    {
+        item2 = it2->next();
+        if(!item2)
+            break;
+
+        if(generalCompare(item1, item2, context))
+            return true;
+
+        cache.append(item2);
+    }
+
+    while(true)
+    {
+        item1 = it1->next();
+
+        if(!item1)
+            return false;
+
+        const Item::List::const_iterator end(cache.constEnd());
+        Item::List::const_iterator it(cache.constBegin());
+
+        for(; it != end; ++it)
+            if(generalCompare(item1, *it, context))
+                return true;
+    }
+
+    Q_ASSERT(false);
+    return false;
+}
+
+Expression::Ptr GeneralComparison::compress(const StaticContext::Ptr &context)
+{
+    const Expression::Ptr me(PairContainer::compress(context));
+
+    if(me != this)
+        return me;
+
+    if(ValueComparison::isCaseInsensitiveCompare(m_operand1, m_operand2))
+        useCaseInsensitiveComparator();
+
+    return me;
+}
+
+Expression::Ptr GeneralComparison::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());
+
+    if(*CommonSequenceTypes::Empty == *t1 ||
+       *CommonSequenceTypes::Empty == *t2)
+    {
+        return wrapLiteral(CommonValues::BooleanFalse, context, this);
+    }
+
+    if(*BuiltinTypes::xsAnyAtomicType == *t1 ||
+       *BuiltinTypes::xsAnyAtomicType == *t2)
+        return me;
+
+    prepareComparison(fetchGeneralComparator(m_operand1, m_operand2, context));
+
+    if(!m_operand1->staticType()->cardinality().allowsMany() &&
+       !m_operand2->staticType()->cardinality().allowsMany())
+    {
+        /* Rewrite to a ValueComparison whose operands uses typing rules
+         * as for an general comparison(that's what's done above). */
+        return rewrite(Expression::Ptr(new ValueComparison(m_operand1,
+                                                           m_operator,
+                                                           m_operand2))->typeCheck(context, reqType),
+                       context);
+    }
+    else
+        return me;
+}
+
+void GeneralComparison::updateType(ItemType::Ptr &type,
+                                   const Expression::Ptr &source)
+{
+    type = source->staticType()->itemType();
+}
+
+AtomicComparator::Ptr GeneralComparison::fetchGeneralComparator(Expression::Ptr &op1,
+                                                                Expression::Ptr &op2,
+                                                                const ReportContext::Ptr &context) const
+{
+    ItemType::Ptr t1(op1->staticType()->itemType());
+    ItemType::Ptr t2(op2->staticType()->itemType());
+
+    /* a. "If one of the atomic values is an instance of xs:untypedAtomic and
+     *    the other is an instance of a numeric type, then the xs:untypedAtomic
+     *    value is cast to the type xs:double." */
+    if(BuiltinTypes::numeric->xdtTypeMatches(t1) &&
+       BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2))
+    {
+        op2 = Expression::Ptr(new UntypedAtomicConverter(op2, BuiltinTypes::xsDouble));
+
+        /* The types might have changed, reload. */
+        updateType(t2, op2);
+    }
+    else if(BuiltinTypes::numeric->xdtTypeMatches(t2) &&
+            BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1))
+    {
+        op1 = Expression::Ptr(new UntypedAtomicConverter(op1, BuiltinTypes::xsDouble));
+
+        /* The types might have changed, reload. */
+        updateType(t1, op1);
+    }
+    /* "If XPath 1.0 compatibility mode is true, a general comparison is
+     *  evaluated by applying the following rules, in order:
+     *  1. If either operand is a single atomic value that is an instance of
+     *  xs:boolean, then the other operand is converted to xs:boolean by taking
+     *  its effective boolean value."
+     *
+     * Notably, it's not conversion to boolean, it is EBV extraction.
+     */
+    else if(m_isBackwardsCompat && BuiltinTypes::xsBoolean->xdtTypeMatches(t1))
+    {
+        op2 = Expression::Ptr(new EBVExtractor(op2));
+        updateType(t2, op2);
+    }
+    else if(m_isBackwardsCompat && BuiltinTypes::xsBoolean->xdtTypeMatches(t2))
+    {
+        op1 = Expression::Ptr(new EBVExtractor(op1));
+        updateType(t1, op1);
+    }
+    /* b. "If one of the atomic values is an instance of xs:untypedAtomic and
+     *    the other is an instance of xs:untypedAtomic or xs:string, then the
+     *    xs:untypedAtomic value (or values) is (are) cast to the type xs:string."
+     *
+     * c. "If one of the atomic values is an instance of xs:untypedAtomic and the
+     *    other is not an instance of xs:string, xs:untypedAtomic, or any numeric
+     *    type, then the xs:untypedAtomic value is cast to the dynamic type of the
+     *    other value." */
+    else if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1) &&
+            !BuiltinTypes::xsString->xdtTypeMatches(t2) &&
+            !BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2) &&
+            !BuiltinTypes::xsAnyURI->xdtTypeMatches(t2))
+    {
+        op1 = Expression::Ptr(new UntypedAtomicConverter(op1, t2));
+        updateType(t1, op1);
+    }
+    else if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2) &&
+            !BuiltinTypes::xsString->xdtTypeMatches(t1) &&
+            !BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1) &&
+            !BuiltinTypes::xsAnyURI->xdtTypeMatches(t1))
+    {
+        op2 = Expression::Ptr(new UntypedAtomicConverter(op2, t1));
+        updateType(t2, op2);
+    }
+
+    /* d. "After performing the conversions described above, the atomic
+     *     values are compared using one of the value comparison operators
+     *     eq, ne, lt, le, gt, or ge, depending on whether the general comparison
+     *     operator was =, !=, <, <=, >, or >=. The values have the required
+     *     magnitude relationship if and only if the result of this value comparison
+     *     is true." */
+
+    return fetchComparator(t1, t2, context);
+}
+
+OptimizationPass::List GeneralComparison::optimizationPasses() const
+{
+    Q_ASSERT(!OptimizationPasses::comparisonPasses.isEmpty());
+    return OptimizationPasses::comparisonPasses;
+}
+
+SequenceType::List GeneralComparison::expectedOperandTypes() const
+{
+    SequenceType::List result;
+    result.append(CommonSequenceTypes::ZeroOrMoreAtomicTypes);
+    result.append(CommonSequenceTypes::ZeroOrMoreAtomicTypes);
+    return result;
+}
+
+SequenceType::Ptr GeneralComparison::staticType() const
+{
+    return CommonSequenceTypes::ExactlyOneBoolean;
+}
+
+ExpressionVisitorResult::Ptr GeneralComparison::accept(const ExpressionVisitor::Ptr &visitor) const
+{
+    return visitor->visit(this);
+}
+
+Expression::ID GeneralComparison::id() const
+{
+    return IDGeneralComparison;
+}
+
+QT_END_NAMESPACE