/*
---- 
This file is part of SECONDO.

Copyright (C) 2004, University in Hagen, Department of Computer Science, 
Database Systems for New Applications.

SECONDO 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.

SECONDO is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with SECONDO; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
----

//paragraph	[10]	title:		[{\Large \bf ] [}]
//paragraph	[11]	title:		[{\large \bf ] [}]
//paragraph	[12]	title:		[{\normalsize \bf ] [}]
//paragraph	[21]	table1column:	[\begin{quote}\begin{tabular}{l}]	[\end{tabular}\end{quote}]
//paragraph	[22]	table2columns:	[\begin{quote}\begin{tabular}{ll}]	[\end{tabular}\end{quote}]
//paragraph	[23]	table3columns:	[\begin{quote}\begin{tabular}{lll}]	[\end{tabular}\end{quote}]
//paragraph	[24]	table4columns:	[\begin{quote}\begin{tabular}{llll}]	[\end{tabular}\end{quote}]
//[--------]	[\hline]
//characters	[1]	verbatim:	[$]	[$]
//characters	[2]	formula:	[$]	[$]
//characters    [3]    capital:    [\textsc{]    [}]
//characters	[4]	teletype:	[\texttt{]	[}]
//[ae] [\"a]
//[oe] [\"o]
//[ue] [\"u]
//[ss] [{\ss}]
//[<=] [\leq]
//[#]  [\neq]
//[tilde] [\verb|~|]

1 Header File: IndexableAttribute

May 1998 Stefan Dieker

December 1998 Friedhelm Becker

April 2002 Ulrich Telle Adjustments for the new Secondo version

1 Class ~IndexableAttribute~

*/

#ifndef INDEXABLEATTRIBUTE_H
#define INDEXABLEATTRIBUTE_H

#include "Attribute.h"

/*
2 Class ~IndexableAttribute~

This class is intended to be used for data types that need to be indexed by B-Trees.
The standard types such as ~int~, ~string~, and ~real~ are directly supported. For
the other (more complex) data types, they need to be converted to a string 
(char pointer) and then indexed. The string representation of the objects should 
preserve the ordering. These data types must also belong to the kind ~INDEXABLE~. 
For an example, see the ~DateTime~ algebra.

*/

class IndexableAttribute : public Attribute
{
  public:
    IndexableAttribute() {}

    IndexableAttribute(const bool defined): Attribute(defined){}

    virtual void WriteTo( char *dest ) const = 0;
/*
This function writes the object value to a string ~dest~.

*/

    virtual void ReadFrom( const char *src ) = 0;
/*
This function reads the object value from a string ~src~.

*/

    virtual SmiSize SizeOfChars() const = 0;
/*
This function returns the number of bytes of the object's string representation.

*/


};

#endif