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#ifndef _QueryLexer_h_
#define _QueryLexer_h_
//
// QueryLexer.h
//
// QueryLexer: (abstract) a lexical analyzer used by a QueryParser.
// This class defines the common public interface of this
// family of lexers. It implements a tokenizer, and also
// the definition of the 'quote' and 'end' terminal symbols.
//
// 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: QueryLexer.h,v 1.4 2004/05/28 13:15:24 lha Exp $
//
#ifdef HAVE_CONFIG_H
#include "htconfig.h"
#endif
#include "htString.h"
class QueryLexer
{
public:
virtual ~QueryLexer() {}
// set the query string and advance to the first token
void Set(const String &query_string);
// advance to the next token
virtual void Next();
// is the current token a word?
virtual bool IsWord() const = 0;
// is the current token a quote sign?
bool IsQuote() const;
// is the current token end-of-query?
bool IsEnd() const;
// get the current token value
const String &Value() const { return current; }
// get the full query string
const String &FullString() const { return query; }
protected:
QueryLexer();
// the full query string
String query;
// the current token value
String current;
// the current position in the query string
int current_char;
// suffix string used by the 'prefix' fuzzy
String prefix_match;
};
#endif
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