File indexing completed on 2024-04-28 11:39:41

 /*
  * predicate.h - Copyright 2005 Frerich Raabe <raabe@kde.org>
  *
  * 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 PREDICATE_H
 #define PREDICATE_H
 
 #include "expression.h"
 
 namespace khtml
 {
 namespace XPath
 {
 
 class Number : public Expression
 {
 public:
     Number(double value);
 
     bool isConstant() const override;
     QString dump() const override;
 
 private:
     Value doEvaluate() const override;
 
     double m_value;
 };
 
 class String : public Expression
 {
 public:
     String(const DOM::DOMString &value);
 
     bool isConstant() const override;
     QString dump() const override;
 
 private:
     Value doEvaluate() const override;
 
     DOM::DOMString m_value;
 };
 
 class Negative : public Expression
 {
 public:
     QString dump() const override;
 
 private:
     Value doEvaluate() const override;
 };
 
 class BinaryExprBase : public Expression
 {
 public:
     QString dump() const override;
 
 protected:
     virtual QString opName() const = 0;
 };
 
 class NumericOp : public BinaryExprBase
 {
 public:
     enum {
         OP_Add = 1,
         OP_Sub,
         OP_Mul,
         OP_Div,
         OP_Mod
     };
 
     NumericOp(int opCode, Expression *lhs, Expression *rhs);
 
 private:
     QString opName() const override;
     Value doEvaluate() const override;
     int opCode;
 };
 
 class RelationOp : public BinaryExprBase
 {
 public:
     enum {
         OP_GT = 1,
         OP_LT,
         OP_GE,
         OP_LE,
         OP_EQ,
         OP_NE
     };
 
     RelationOp(int opCode, Expression *lhs, Expression *rhs);
 
 private:
     QString opName() const override;
     Value doEvaluate() const override;
     int opCode;
 
     // compares strings based on the op-code
     bool compareStrings(const DOM::DOMString &l, const DOM::DOMString &r) const;
     bool compareNumbers(double l, double r) const;
 };
 
 class LogicalOp : public BinaryExprBase
 {
 public:
     enum {
         OP_And = 1,
         OP_Or
     };
 
     LogicalOp(int opCode, Expression *lhs, Expression *rhs);
 
     bool isConstant() const override;
 
 private:
     bool    shortCircuitOn() const;
     QString opName() const override;
     Value doEvaluate() const override;
     int opCode;
 };
 
 class Union : public BinaryExprBase
 {
 private:
     QString opName() const override;
     Value doEvaluate() const override;
 };
 
 class Predicate
 {
 public:
     Predicate(Expression *expr);
     ~Predicate();
 
     bool evaluate() const;
 
     void optimize();
     QString dump() const;
 
 private:
     Predicate(const Predicate &rhs);
     Predicate &operator=(const Predicate &rhs);
 
     Expression *m_expr;
 };
 
 } // namespace XPath
 
 } // namespace khtml
 
 #endif // PREDICATE_H