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

/*
 * Copyright 2005 Frerich Raabe <raabe@kde.org>
 * Copyright (C) 2006 Apple Computer, 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 XPathPredicate_h
#define XPathPredicate_h

#include "core/xml/XPathExpressionNode.h"
#include "core/xml/XPathValue.h"

namespace blink {

namespace XPath {

class Number final : public Expression {
public:
    explicit Number(double);
    DECLARE_VIRTUAL_TRACE();

private:
    Value evaluate(EvaluationContext&) const override;
    Value::Type resultType() const override { return Value::NumberValue; }

    Value m_value;
};

class StringExpression final : public Expression {
public:
    explicit StringExpression(const String&);
    DECLARE_VIRTUAL_TRACE();

private:
    Value evaluate(EvaluationContext&) const override;
    Value::Type resultType() const override { return Value::StringValue; }

    Value m_value;
};

class Negative final : public Expression {
private:
    Value evaluate(EvaluationContext&) const override;
    Value::Type resultType() const override { return Value::NumberValue; }
};

class NumericOp final : public Expression {
public:
    enum Opcode {
        OP_Add, OP_Sub, OP_Mul, OP_Div, OP_Mod
    };
    NumericOp(Opcode, Expression* lhs, Expression* rhs);

private:
    Value evaluate(EvaluationContext&) const override;
    Value::Type resultType() const override { return Value::NumberValue; }

    Opcode m_opcode;
};

class EqTestOp final : public Expression {
public:
    enum Opcode { OpcodeEqual, OpcodeNotEqual, OpcodeGreaterThan, OpcodeLessThan, OpcodeGreaterOrEqual, OpcodeLessOrEqual };
    EqTestOp(Opcode, Expression* lhs, Expression* rhs);
    Value evaluate(EvaluationContext&) const override;

private:
    Value::Type resultType() const override { return Value::BooleanValue; }
    bool compare(EvaluationContext&, const Value&, const Value&) const;

    Opcode m_opcode;
};

class LogicalOp final : public Expression {
public:
    enum Opcode { OP_And, OP_Or };
    LogicalOp(Opcode, Expression* lhs, Expression* rhs);

private:
    Value::Type resultType() const override { return Value::BooleanValue; }
    bool shortCircuitOn() const;
    Value evaluate(EvaluationContext&) const override;

    Opcode m_opcode;
};

class Union final : public Expression {
private:
    Value evaluate(EvaluationContext&) const override;
    Value::Type resultType() const override { return Value::NodeSetValue; }
};

class Predicate final : public GarbageCollected<Predicate> {
    WTF_MAKE_NONCOPYABLE(Predicate);
public:
    explicit Predicate(Expression*);
    DECLARE_TRACE();

    bool evaluate(EvaluationContext&) const;
    bool isContextPositionSensitive() const { return m_expr->isContextPositionSensitive() || m_expr->resultType() == Value::NumberValue; }
    bool isContextSizeSensitive() const { return m_expr->isContextSizeSensitive(); }

private:
    Member<Expression> m_expr;
};

} // namespace XPath

} // namespace blink

#endif // XPathPredicate_h