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Diffstat (limited to 'src/xmlpatterns/data/qatomiccomparator_p.h')
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diff --git a/src/xmlpatterns/data/qatomiccomparator_p.h b/src/xmlpatterns/data/qatomiccomparator_p.h new file mode 100644 index 0000000000..2ec7815d63 --- /dev/null +++ b/src/xmlpatterns/data/qatomiccomparator_p.h @@ -0,0 +1,223 @@ +/**************************************************************************** +** +** 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. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +// +// W A R N I N G +// ------------- +// +// This file is not part of the Qt API. It exists purely as an +// implementation detail. This header file may change from version to +// version without notice, or even be removed. +// +// We mean it. + +#ifndef Patternist_AtomicComparator_H +#define Patternist_AtomicComparator_H + +#include <QFlags> + +#include "qitem_p.h" +#include "qatomictypedispatch_p.h" + +QT_BEGIN_HEADER + +QT_BEGIN_NAMESPACE + +class QString; + +namespace QPatternist +{ + + /** + * @short Base class for classes responsible of comparing two atomic values. + * + * This class is also known as the AtomicParrot. + * + * @ingroup Patternist_xdm + * @author Frans Englich <fenglich@trolltech.com> + */ + class Q_AUTOTEST_EXPORT AtomicComparator : public AtomicTypeVisitorResult + { + public: + AtomicComparator(); + virtual ~AtomicComparator(); + + typedef QExplicitlySharedDataPointer<AtomicComparator> Ptr; + + /** + * Identifies operators used in value comparisons. + * + * The enum values are bit-significant. + * + * @see <a href="http://www.w3.org/TR/xpath20/#id-value-comparisons">W3C XML Path + * Language (XPath) 2.0, 3.5.1 Value Comparisons</a> + */ + enum Operator + { + /** + * Operator <tt>eq</tt> and <tt>=</tt>. + */ + OperatorEqual = 1, + + /** + * Operator <tt>ne</tt> and <tt>!=</tt>. + */ + OperatorNotEqual = 1 << 1, + + /** + * Operator <tt>gt</tt> and <tt>\></tt>. + */ + OperatorGreaterThan = 1 << 2, + + /** + * Operator <tt>lt</tt> and <tt>\<</tt>. + */ + OperatorLessThan = 1 << 3, + + /** + * One of the operators we use for sorting. The only difference from + * OperatorLessThan is that it sees NaN as ordered and smaller than + * other numbers. + */ + OperatorLessThanNaNLeast = 1 << 4, + + /** + * One of the operators we use for sorting. The only difference from + * OperatorLessThanLeast is that it sees NaN as ordered and larger than + * other numbers. + */ + OperatorLessThanNaNGreatest = 1 << 5, + + /** + * Operator <tt>ge</tt> and <tt>\>=</tt>. + */ + OperatorGreaterOrEqual = OperatorEqual | OperatorGreaterThan, + + /** + * Operator <tt>le</tt> and <tt>\<=</tt>. + */ + OperatorLessOrEqual = OperatorEqual | OperatorLessThan + }; + + typedef QFlags<Operator> Operators; + + /** + * Signifies the result of a value comparison. This is used for value comparisons, + * and in the future likely also for sorting. + * + * @see <a href="http://www.w3.org/TR/xpath20/#id-value-comparisons">W3C XML Path + * Language (XPath) 2.0, 3.5.1 Value Comparisons</a> + */ + enum ComparisonResult + { + LessThan = 1, + Equal = 2, + GreaterThan = 4, + Incomparable = 8 + }; + + /** + * Compares @p op1 and @p op2 and determines the relationship between the two. This + * is used for sorting and comparisons. The implementation performs an assert crash, + * and must therefore be re-implemented if comparing the relevant values should be + * possible. + * + * @param op1 the first operand + * @param op the operator. How a comparison is carried out shouldn't depend on what the + * operator is, but in some cases it is of interest. + * @param op2 the second operand + */ + virtual ComparisonResult compare(const Item &op1, + const AtomicComparator::Operator op, + const Item &op2) const; + + /** + * Determines whether @p op1 and @p op2 are equal. It is the same as calling compare() + * and checking whether the return value is Equal, but since comparison testing is such + * a common operation, this specialized function exists. + * + * @returns true if @p op1 and @p op2 are equal. + * + * @param op1 the first operand + * @param op2 the second operand + */ + virtual bool equals(const Item &op1, + const Item &op2) const = 0; + + /** + * Identifies the kind of comparison. + */ + enum ComparisonType + { + /** + * Identifies a general comparison; operator @c =, @c >, @c <=, and so on. + */ + AsGeneralComparison = 1, + + /** + * Identifies a value comparison; operator @c eq, @c lt, @c le, and so on. + */ + AsValueComparison + }; + + /** + * Utility function for getting the lexical representation for + * the comparison operator @p op. Depending on the @p type argument, + * the string returned is either a general comparison or a value comparison + * operator. + * + * @param op the operator which the display name should be determined for. + * @param type signifies whether the returned display name should be for + * a value comparison or a general comparison. For example, if @p op is + * OperatorEqual and @p type is AsValueComparision, "eq" is returned. + */ + static QString displayName(const AtomicComparator::Operator op, + const ComparisonType type); + + }; + Q_DECLARE_OPERATORS_FOR_FLAGS(AtomicComparator::Operators) +} + +QT_END_NAMESPACE + +QT_END_HEADER + +#endif |