/*
** $Id$
** Lexical Analizer
** See Copyright Notice in lua.h
*/

#ifndef llex_h
#define llex_h

#include "engine/lua/lobject.h"
#include "engine/lua/lzio.h"

#define FIRST_RESERVED	260

// maximum length of a reserved word (+1 for terminal 0)
#define TOKEN_LEN	15

enum RESERVED {
	// terminal symbols denoted by reserved words
	AND = FIRST_RESERVED,
	DO, ELSE, ELSEIF, END, FUNCTION, IF, LOCAL, NIL, NOT, OR,
	REPEAT, RETURN, THEN, UNTIL, WHILE,
	// other terminal symbols
	NAME, CONC, DOTS, EQ, GE, LE, NE, NUMBER, STRING, EOS
};

#define MAX_IFS 5

// "ifstate" keeps the state of each nested $if the lexical is dealing with.

struct ifState {
	int32 elsepart;  // true if its in the $else part
	int32 condition;  // true if $if condition is true
	int32 skip;  // true if part must be skipped
};

typedef struct LexState {
	int32 current;  // look ahead character
	int32 token;  // look ahead token
	struct FuncState *fs;  // 'FuncState' is private for the parser
	union {
		real r;
		TaggedString *ts;
	} seminfo;  // semantics information
	zio *lex_z;  // input stream
	int32 linenumber;  // input line counter
	int32 iflevel;  // level of nested $if's (for lexical analysis)
	ifState ifstate[MAX_IFS];
} LexState;

void luaX_init();
void luaX_setinput(LexState *LS, ZIO *z);
int32 luaX_lex(LexState *LS);
void luaX_syntaxerror(LexState *ls, const char *s, const char *token);
void luaX_error(LexState *ls, const char *s);
void luaX_token2str(LexState *ls, int32 token, char *s);

#endif