lexer.hpp

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/*
 * This file is part of Algorithms library toolkit.
 * Copyright (C) 2017 Jan Travnicek (jan.travnicek@fit.cvut.cz)
 
 * Algorithms library toolkit 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 3 of the License, or
 * (at your option) any later version.
 
 * Algorithms library toolkit 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 Algorithms library toolkit.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#pragma once
 
#include <exception>
 
#include <ext/istream>
 
namespace ext {
 
class BasicLexer {
public:
    static void putback ( ext::istream & input, const std::string & data );
 
    static bool test ( ext::istream & input, const std::string & value );
 
    static void consume ( ext::istream & input, const std::string & value );
 
    static bool testAndConsume ( ext::istream & input, const std::string & value );
 
};
 
template < typename SuperLexer >
class Lexer : public BasicLexer {
public:
    struct Token {
        typename SuperLexer::TokenType type;
        std::string value;
        std::string raw;
    };
 
    static Token peek ( ext::istream & input ) {
        Token token = SuperLexer::next ( input );
        putback ( input, token );
        return token;
    }
 
    using BasicLexer::putback;
 
    static void putback ( ext::istream & input, const Token & token ) {
        putback ( input, token.raw );
    }
 
};
 
} /* namespace ext */