LispRowCol.h

#ifndef LISPROWCOL_H
#define LISPROWCOL_H

/*
* Copyright 2024 Rochus Keller <mailto:me@rochus-keller.ch>
*
* This file is part of the Interlisp project.
*
* The following is the license that applies to this copy of the
* library. For a license to use the library under conditions
* other than those described here, please email to me@rochus-keller.ch.
*
* GNU General Public License Usage
* This file may be used under the terms of the GNU General Public
* License (GPL) versions 2.0 or 3.0 as published by the Free Software
* Foundation and appearing in the file LICENSE.GPL included in
* the packaging of this file. Please review the following information
* to ensure GNU General Public Licensing requirements will be met:
* http://www.fsf.org/licensing/licenses/info/GPLv2.html and
* http://www.gnu.org/copyleft/gpl.html.
*/

#include <QByteArray>

namespace Lisp
{

struct RowCol
{
    enum { ROW_BIT_LEN = 19, COL_BIT_LEN = 32 - ROW_BIT_LEN - 1 };
    uint row : ROW_BIT_LEN; // supports 524k lines
    uint col : COL_BIT_LEN; // supports 4k chars per line
    uint unused : 1; // the sign is used to recognize the packed representation

    RowCol():row(0),col(0),unused(0) {}
    RowCol( quint32 row, quint32 col );
    bool setRowCol( quint32 row, quint32 col );
    bool isValid() const { return row > 0 && col > 0; } // valid lines and cols start with 1; 0 is invalid
    bool operator==( const RowCol& rhs ) const { return row == rhs.row && col == rhs.col; }

    quint32 packed() const { return ( row << COL_BIT_LEN ) | col; }
    static bool isPacked( quint32 rowCol ) { return rowCol; }
    static quint32 unpackCol(quint32 rowCol ) { return rowCol & ( ( 1 << COL_BIT_LEN ) -1 ); }
    static quint32 unpackRow(quint32 rowCol ) { return ( ( rowCol ) >> COL_BIT_LEN ); }
};

}

#endif // LISPROWCOL_H