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| |
| // |
| // 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_NodeComparison_H |
| #define Patternist_NodeComparison_H |
| |
| #include <private/qpaircontainer_p.h> |
| |
| QT_BEGIN_NAMESPACE |
| |
| namespace QPatternist |
| { |
| |
| /** |
| * @short Implements the node comparison operators <tt>\>\></tt>, <tt>\<\<</tt>, and @c is. |
| * |
| * @see <a href="http://www.w3.org/TR/xpath20/#id-node-comparisons">XML Path Language |
| * (XPath) 2.0, 3.5.3 QXmlNodeModelIndex Comparisons</a> |
| * @author Frans Englich <frans.englich@nokia.com> |
| * @ingroup Patternist_expressions |
| */ |
| class Q_AUTOTEST_EXPORT NodeComparison : public PairContainer |
| { |
| public: |
| NodeComparison(const Expression::Ptr &operand1, |
| const QXmlNodeModelIndex::DocumentOrder op, |
| const Expression::Ptr &operand2); |
| |
| virtual Item evaluateSingleton(const DynamicContext::Ptr &) const; |
| virtual bool evaluateEBV(const DynamicContext::Ptr &) const; |
| |
| virtual SequenceType::List expectedOperandTypes() const; |
| |
| virtual QXmlNodeModelIndex::DocumentOrder operatorID() const; |
| /** |
| * If any operator is the empty sequence, the NodeComparison rewrites |
| * into that, since the empty sequence is always the result in that case. |
| */ |
| virtual Expression::Ptr compress(const StaticContext::Ptr &context); |
| |
| /** |
| * @returns either CommonSequenceTypes::ZeroOrOneBoolean or |
| * CommonSequenceTypes::ExactlyOneBoolean depending on the static |
| * cardinality of its operands. |
| */ |
| virtual SequenceType::Ptr staticType() const; |
| |
| /** |
| * Determines the string representation for a node comparison operator. |
| * |
| * @returns |
| * - "<<" if @p op is Precedes |
| * - ">>" if @p op is Follows |
| * - "is" if @p op is Is |
| */ |
| static QString displayName(const QXmlNodeModelIndex::DocumentOrder op); |
| |
| virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const; |
| private: |
| enum Result |
| { |
| Empty, |
| True, |
| False |
| }; |
| inline Result evaluate(const DynamicContext::Ptr &context) const; |
| |
| const QXmlNodeModelIndex::DocumentOrder m_op; |
| |
| }; |
| } |
| |
| QT_END_NAMESPACE |
| |
| #endif |