third_party/WebKit/Source/core/xml/XPathExpressionNode.h

   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 #include "core/dom/Node.h"
  31 #include "core/xml/XPathValue.h"
  32 #include "wtf/HashMap.h"
  33 #include "wtf/Vector.h"
  34 #include "wtf/text/StringHash.h"
  35
  36 namespace blink {
  37
  38 namespace XPath {
  39
  40 struct EvaluationContext {
  41     STACK_ALLOCATED();
  42 public:
  43     explicit EvaluationContext(Node&);
  44
  45     RefPtrWillBeMember<Node> node;
  46     unsigned long size;
  47     unsigned long position;
  48     HashMap<String, String> variableBindings;
  49
  50     bool hadTypeConversionError;
  51 };
  52
  53 class ParseNode : public GarbageCollectedFinalized<ParseNode> {
  54 public:
  55     virtual ~ParseNode() { }
  56     DEFINE_INLINE_VIRTUAL_TRACE() { }
  57 };
  58
  59 class Expression : public ParseNode {
  60     WTF_MAKE_NONCOPYABLE(Expression);
  61 public:
  62     Expression();
  63     ~Expression() override;
  64     DECLARE_VIRTUAL_TRACE();
  65
  66     virtual Value evaluate(EvaluationContext&) const = 0;
  67
  68     void addSubExpression(Expression* expr)
  69     {
  70         m_isContextNodeSensitive |= expr->m_isContextNodeSensitive;
  71         m_isContextPositionSensitive |= expr->m_isContextPositionSensitive;
  72         m_isContextSizeSensitive |= expr->m_isContextSizeSensitive;
  73         m_subExpressions.append(expr);
  74     }
  75
  76     bool isContextNodeSensitive() const { return m_isContextNodeSensitive; }
  77     bool isContextPositionSensitive() const { return m_isContextPositionSensitive; }
  78     bool isContextSizeSensitive() const { return m_isContextSizeSensitive; }
  79     void setIsContextNodeSensitive(bool value) { m_isContextNodeSensitive = value; }
  80     void setIsContextPositionSensitive(bool value) { m_isContextPositionSensitive = value; }
  81     void setIsContextSizeSensitive(bool value) { m_isContextSizeSensitive = value; }
  82
  83     virtual Value::Type resultType() const = 0;
  84
  85 protected:
  86     unsigned subExprCount() const { return m_subExpressions.size(); }
  87     Expression* subExpr(unsigned i) { return m_subExpressions[i].get(); }
  88     const Expression* subExpr(unsigned i) const { return m_subExpressions[i].get(); }
  89
  90 private:
  91     HeapVector<Member<Expression>> m_subExpressions;
  92
  93     // Evaluation details that can be used for optimization.
  94     bool m_isContextNodeSensitive;
  95     bool m_isContextPositionSensitive;
  96     bool m_isContextSizeSensitive;
  97 };
  98
  99 } // namespace XPath
 100
 101 } // namespace blink
 102
 103 #endif // XPathExpressionNode_h