/* -*- C++ -*-
 * Copyright ©2004 Hugo Mills <hugo@carfax.org.uk>
 *
 * This software is distributed under the terms of the GNU GPL v3
 * For more information on the GPL, see the file COPYING or 
 * visit http://www.gnu.org/
 *
 * This software is distributed without warranty
 */

#ifndef CONFIGLEXER_H
#define CONFIGLEXER_H

#include <iostream>
#include <string>
#include <utility>

class UnexpectedEOF { };

typedef enum {
	UNINITIALISED, END, FLOAT, INTEGER, TOKEN, STRING, CHAR
} LexType;

typedef std::pair<LexType, std::string> Token;

class ConfigLexer
{
public:
	ConfigLexer(std::istream* is)
		: input(is),
		  currentvalue(Token(UNINITIALISED, "")),
		  parsestate(WS),
		  line(1)
	{ }
	
	virtual ~ConfigLexer() { }

	ConfigLexer& operator++(void);
	ConfigLexer* next(void);         // Move to the next token
	bool eos(void);                  // Move to next token. Return
									 // false if current token is the
									 // end of section.
	ConfigLexer* section_next(void); // Move to the beginning of the
									 // next section
	ConfigLexer* directive_next(void); // Move to the beginning of the
									   // next directive

	const LexType& type(void) const { 
// 		std::cerr << "Type=" << currentvalue.first << std::endl;
		return currentvalue.first; }
	const std::string& value(void) const { 
// 		std::cerr << "Value=" << currentvalue.second << std::endl;
		return currentvalue.second; }
	int lineno(void) const { return line; }

private:
	std::istream* input;
	Token currentvalue;
	int line;

	enum {
		WS, TEXT, NUMBER, DECIMAL, QUOTEDSTRING,
		PERLCOMMENT, POSSCOMMENT, CCOMMENT, CPPCOMMENT, POSSCOMMENTEND
	} parsestate;
};

extern ConfigLexer* lex;

#endif