1 /*

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

     3  * Copyright (C) 2006, 2009 Apple Inc.

     4  *

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

     6  * modification, are permitted provided that the following conditions

     7  * are met:

     8  * 

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

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

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

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

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

    14  * 

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

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

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

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

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

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

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

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

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

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

    25  */

    26 

    27 #ifndef XPathExpressionNode_h

    28 #define XPathExpressionNode_h

    29 

    30 #if ENABLE(XPATH)

    31 

    32 #include "StringHash.h"

    33 #include "Node.h"

    34 #include "XPathValue.h"

    35 #include <wtf/HashMap.h>

    36 #include <wtf/Vector.h>

    37 

    38 namespace WebCore {

    39 

    40     namespace XPath {

    41         

    42         struct EvaluationContext : FastAllocBase {

    43             RefPtr<Node> node;

    44             unsigned long size;

    45             unsigned long position;

    46             HashMap<String, String> variableBindings;

    47 

    48             bool hadTypeConversionError;

    49         };

    50 

    51         class ParseNode {

    52         public:

    53             virtual ~ParseNode() { }

    54         };

    55 

    56         class Expression : public ParseNode, public Noncopyable {

    57         public:

    58             static EvaluationContext& evaluationContext();

    59 

    60             Expression();

    61             virtual ~Expression();

    62 

    63             virtual Value evaluate() const = 0;

    64 

    65             void addSubExpression(Expression* expr)

    66             {

    67                 m_subExpressions.append(expr);

    68                 m_isContextNodeSensitive |= expr->m_isContextNodeSensitive;

    69                 m_isContextPositionSensitive |= expr->m_isContextPositionSensitive;

    70                 m_isContextSizeSensitive |= expr->m_isContextSizeSensitive;

    71             }

    72 

    73             bool isContextNodeSensitive() const { return m_isContextNodeSensitive; }

    74             bool isContextPositionSensitive() const { return m_isContextPositionSensitive; }

    75             bool isContextSizeSensitive() const { return m_isContextSizeSensitive; }

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

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

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

    79 

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

    81 

    82         protected:

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

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

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

    86 

    87         private:

    88             Vector<Expression*> m_subExpressions;

    89 

    90             // Evaluation details that can be used for optimization.

    91             bool m_isContextNodeSensitive;

    92             bool m_isContextPositionSensitive;

    93             bool m_isContextSizeSensitive;

    94         };

    95 

    96     }

    97 

    98 }

    99 

   100 #endif // ENABLE(XPATH)

   101 

   102 #endif // EXPRESSION_H

   103