/*
 * Copyright (C) 2007-2019 Xagasoft, All rights reserved.
 *
 * This file is part of the libbu++ library and is released under the
 * terms of the license contained in the file LICENSE.
 */

#ifndef BU_LEXER_H
#define BU_LEXER_H

#include "bu/variant.h"

namespace Bu
{
    class Stream;

    /**
     * The base class for creating a lexical analyzer.  This is designed to work
     * in tandem with the Bu::Parser class, which uses this to tokenize textual
     * input.  It can be used by just about anything that cares about tokens
     * more than raw input, though.
     */
    class Lexer
    {
    public:
        Lexer();
        virtual ~Lexer();

        typedef int TokenType;

        class Token
        {
        public:
            Token();
            Token( TokenType iToken );

            template<class t>
            Token( TokenType iToken, const t &v ) :
                iToken( iToken )//,
//              vExtra( v )
            {
                vExtra = v;
            }
            TokenType iToken;
            Bu::Variant vExtra;
            int iStartCol;
            int iStartRow;
            int iEndCol;
            int iEndRow;
        };

        virtual Token *nextToken()=0;

        virtual Bu::String tokenToString( const Token &t );
    };
};

#endif