object_parser.h

/***************************************************************************
 *   Copyright (C) 2004-2006 by Radko Mihal                                *
 *   rmihal@pobox.sk                                                       *
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 *   This program 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 this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.              *
 ***************************************************************************/
#ifndef GRAMMAR_TO_PARSEROBJECT_PARSER_H
#define GRAMMAR_TO_PARSEROBJECT_PARSER_H


namespace grammar_to_parser {

template< typename E, typename A >
class basic_object_parser : public basic_parser<E>, public std::auto_ptr<A>
{
public:
typedef std::auto_ptr<A> std_auto_ptr;
typedef typename basic_parser<E>::symbol_type symbol_type;
        basic_object_parser( const char* name, symbol_type type = terminal_type);
        
        basic_object_parser( const char* name, 
                                                const A &rhs, 
                                                symbol_type type = terminal_type);
         
        basic_object_parser( const basic_object_parser& rhs );
                
    virtual ~basic_object_parser();
        
        virtual bool is_valid() const { return get() != NULL; }

        virtual A& get_valid()
        {
                if( !is_valid() ) 
                {
                        std_auto_ptr::operator=( std_auto_ptr(new A()) );
                }
                return std_auto_ptr::operator *();
        }
        
        virtual void invalidate() 
        { 
                std_auto_ptr::operator = ( std_auto_ptr(NULL) ); 
        }
        
//      virtual void trace_on_fly() 
//      {
//              get_valid().get_name();
//      }
        
protected:
        virtual void prepare_for_parsing()
        {
                basic_parser<E>::prepare_for_parsing();
                get_valid();
        }
        virtual void prepare_for_formatting() 
        {
                basic_parser<E>::prepare_for_formatting();
                get_valid();
        };
};

template< typename E, typename A >
basic_object_parser<E,A>::basic_object_parser( const char* name, symbol_type type ) 
: basic_parser<E>(name,type), std::auto_ptr<A>(NULL) 
{
}

template< typename E, typename A >
basic_object_parser<E,A>::basic_object_parser( const char* name, 
                                                                                                const A &rhs, 
                                                                                                symbol_type type )
: basic_parser<E>(name,type), std::auto_ptr<A>( new A(rhs) ) 
{
}

// !!!! - the conversion from const to non const - if someone wants a 
// copy of A object, should use previous constructor
template< typename E, typename A >
basic_object_parser<E,A>::basic_object_parser(const basic_object_parser& rhs )
: basic_parser<E>(rhs), std::auto_ptr<A>(const_cast<basic_object_parser&>(rhs).release())
{
}

template< typename E, typename A >
basic_object_parser<E,A>::~basic_object_parser() 
{
}


};

#endif

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