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
36namespace blink {
37
38namespace XPath {
39
40struct EvaluationContext {
41    STACK_ALLOCATED();
42public:
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
53class ParseNode : public NoBaseWillBeGarbageCollectedFinalized<ParseNode> {
54public:
55    virtual ~ParseNode() { }
56    virtual void trace(Visitor*) { }
57};
58
59class Expression : public ParseNode {
60    WTF_MAKE_NONCOPYABLE(Expression); WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
61public:
62    Expression();
63    virtual ~Expression();
64    virtual void trace(Visitor*) OVERRIDE;
65
66    virtual Value evaluate(EvaluationContext&) const = 0;
67
68    void addSubExpression(PassOwnPtrWillBeRawPtr<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
85protected:
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
90private:
91    WillBeHeapVector<OwnPtrWillBeMember<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}
100
101}
102
103#endif // XPathExpressionNode_h
104