/*

 * Copyright (C) 2005 Frerich Raabe <raabe@kde.org>

 * Copyright (C) 2006, 2009 Apple Inc.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef XPathExpressionNode_h

#define XPathExpressionNode_h

#if ENABLE(XPATH)

#include "StringHash.h"

#include "Node.h"

#include "XPathValue.h"

#include <wtf/HashMap.h>

#include <wtf/Vector.h>

namespace WebCore {

    namespace XPath {

        struct EvaluationContext : FastAllocBase {

            RefPtr<Node> node;

            unsigned long size;

            unsigned long position;

            HashMap<String, String> variableBindings;

            bool hadTypeConversionError;

        };

        class ParseNode {

        public:

            virtual ~ParseNode() { }

        };

        class Expression : public ParseNode, public Noncopyable {

        public:

            static EvaluationContext& evaluationContext();

            Expression();

            virtual ~Expression();

            virtual Value evaluate() const = 0;

            void addSubExpression(Expression* expr)

            {

                m_subExpressions.append(expr);

                m_isContextNodeSensitive |= expr->m_isContextNodeSensitive;

                m_isContextPositionSensitive |= expr->m_isContextPositionSensitive;

                m_isContextSizeSensitive |= expr->m_isContextSizeSensitive;

            }

            bool isContextNodeSensitive() const { return m_isContextNodeSensitive; }

            bool isContextPositionSensitive() const { return m_isContextPositionSensitive; }

            bool isContextSizeSensitive() const { return m_isContextSizeSensitive; }

            void setIsContextNodeSensitive(bool value) { m_isContextNodeSensitive = value; }

            void setIsContextPositionSensitive(bool value) { m_isContextPositionSensitive = value; }

            void setIsContextSizeSensitive(bool value) { m_isContextSizeSensitive = value; }

            virtual Value::Type resultType() const = 0;

        protected:

            unsigned subExprCount() const { return m_subExpressions.size(); }

            Expression* subExpr(unsigned i) { return m_subExpressions[i]; }

            const Expression* subExpr(unsigned i) const { return m_subExpressions[i]; }

        private:

            Vector<Expression*> m_subExpressions;

            // Evaluation details that can be used for optimization.

            bool m_isContextNodeSensitive;

            bool m_isContextPositionSensitive;

            bool m_isContextSizeSensitive;

        };

    }

}

#endif // ENABLE(XPATH)

#endif // EXPRESSION_H