parser.h

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/***************************************************************************
    copyright            : (C) 2005 by Inge Wallin
    email                : inge@lysator.liu.se
 ***************************************************************************/
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef PARSER_H
#define PARSER_H

#include "libkdeedu_science_export.h"

#include <QtCore/QString>


class SCIENCE_EXPORT Parser {
public:
    Parser();

    explicit Parser(const QString& _str);
    
    virtual ~Parser();

    void   start(const QString& _str);

    int    nextChar()  const { return m_nextChar;  }

    int    nextToken() const { return m_nextToken; }

    int    intVal()    const { return m_intVal;    }
    float  floatVal()  const { return m_floatVal;  }

private:

    // Try to parse some special datatypes.
    bool  parseInt(int *_result);
    bool  parseSimpleFloat(double *_result);

protected:
    static const  int  INT_TOKEN   = 257;

    static const  int  FLOAT_TOKEN = 258;

    int   getNextChar();

    int   skipWhitespace();

    virtual int   getNextToken();

private:
    QString  m_str;
    int      m_index;
    int      m_nextChar;

 protected:

    // Lexical analysis and token handling.  These members need to be
    // protected instead of private since we want to be able to
    // reimplement getNextToken().

    int      m_nextToken;

    // Values for the respective token.  These could be made into a
    // union, but I don't think it is necessary to bother, since they
    // are so few and we don't instantiate a lot of copies of the
    // parser.
    
    int      m_intVal;      // Valid if m_nextToken == INT_TOKEN

    double   m_floatVal;    // Valid if m_nextToken == FLOAT_TOKEN
};

#endif