You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
69 lines
1.5 KiB
C++
69 lines
1.5 KiB
C++
#ifndef _OperatorQuery_h_
|
|
#define _OperatorQuery_h_
|
|
|
|
//
|
|
// OperatorQuery.h
|
|
//
|
|
// OperatorQuery: (abstract class) a query that combines result lists
|
|
// returned by other queries kept in an operand list.
|
|
// how they are combined is tbd by the concrete classes.
|
|
//
|
|
// Part of the ht://Dig package <http://www.htdig.org/>
|
|
// Copyright (c) 1995-2004 The ht://Dig Group
|
|
// For copyright details, see the file COPYING in your distribution
|
|
// or the GNU Library General Public License (LGPL) version 2 or later
|
|
// <http://www.gnu.org/copyleft/lgpl.html>
|
|
//
|
|
// $Id: OperatorQuery.h,v 1.4 2004/05/28 13:15:24 lha Exp $
|
|
//
|
|
|
|
//
|
|
// for details about the basic architectural pattern see the book:
|
|
// Design Patterns, by the infamous GoF
|
|
// Interpreter pattern
|
|
//
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "htconfig.h"
|
|
#endif
|
|
|
|
#include "Query.h"
|
|
#include "List.h"
|
|
|
|
// abstract
|
|
class OperatorQuery : public Query
|
|
{
|
|
public:
|
|
virtual ~OperatorQuery()
|
|
{
|
|
operands.Destroy();
|
|
}
|
|
|
|
// add an operand to the operation
|
|
void Add(Query *operand)
|
|
{
|
|
operands.Add(operand);
|
|
}
|
|
|
|
protected:
|
|
OperatorQuery() {}
|
|
|
|
// get results from operands and combine them ad-hoc
|
|
virtual ResultList *Evaluate() = 0;
|
|
|
|
// keyword name of the operation
|
|
virtual String OperatorString() const = 0;
|
|
|
|
// human-readable unparsed string
|
|
virtual String GetLogicalWords() const;
|
|
|
|
// cache index
|
|
String GetSignature() const
|
|
{ return String("Compound:")+GetLogicalWords(); }
|
|
|
|
// children query operands
|
|
List operands;
|
|
};
|
|
|
|
#endif
|