src/lexer_scanner.h

/*
	Copyright (c) 2014, Santeri Piippo
	All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions are met:

		* Redistributions of source code must retain the above copyright
		  notice, this list of conditions and the following disclaimer.

		* Redistributions in binary form must reproduce the above copyright
		  notice, this list of conditions and the following disclaimer in the
		  documentation and/or other materials provided with the distribution.

		* Neither the name of the <organization> nor the
		  names of its contributors may be used to endorse or promote products
		  derived from this software without specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
	ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
	DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef BOTC_LEXER_SCANNER_H
#define BOTC_LEXER_SCANNER_H

#include <climits>
#include "main.h"

class lexer_scanner
{
	types:
		struct position_info
		{
			char*	pos;
			char*	line_break_pos;
			int		line;
		};

		// Flags for check_string()
		enum
		{
			f_check_word = (1 << 0),   // must be followed by whitespace
			f_check_peek = (1 << 1),   // don't advance cursor
		};

	public:
		static inline bool is_symbol_char (char c, bool allow_numbers)
		{
			if (allow_numbers && (c >= '0' && c <= '9'))
				return true;

			return (c >= 'a' && c <= 'z') ||
				   (c >= 'A' && c <= 'Z') ||
				   (c == '_');
		}

		lexer_scanner (FILE* fp);
		~lexer_scanner();
		bool get_next_token();

		inline const string& get_token_text() const
		{
			return m_token_text;
		}

		inline int get_line() const
		{
			return m_line;
		}

		inline int get_column() const
		{
			return m_ptr - m_line_break_pos;
		}

		inline e_token get_token_type() const
		{
			return m_token_type;
		}

		static string get_token_string (e_token a);

	private:
		char*			m_data;
		char*			m_ptr;
		char*			m_line_break_pos;
		string			m_token_text,
						m_last_token;
		e_token			m_token_type;
		int				m_line;

		bool			check_string (const char* c, int flags = 0);

		// Yields a copy of the current position information.
		position_info	get_position() const;

		// Sets the current position based on given data.
		void			set_position (const position_info& a);

		// Skips one character
		void			skip();

		// Skips many characters
		void			skip (int chars);
};

#endif // BOTC_LEXER_SCANNER_H