--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qgeneralcomparison.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,297 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 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.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@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