llex.c - external/github.com/lua/lua - Git at Google

 /*
 ** $Id: llex.c,v 1.12 1997/12/22 17:52:20 roberto Exp roberto $
 ** Lexical Analizer
 ** See Copyright Notice in lua.h
 */


 #include <ctype.h>
 #include <string.h>

 #include "lauxlib.h"
 #include "llex.h"
 #include "lmem.h"
 #include "lobject.h"
 #include "lparser.h"
 #include "lstate.h"
 #include "lstring.h"
 #include "lstx.h"
 #include "luadebug.h"
 #include "lzio.h"


 int lua_debug=0;


 #define next(LS) (LS->current = zgetc(LS->lex_z))


 static struct {
   char *name;
   int token;
 } reserved [] = {
     {"and", AND}, {"do", DO}, {"else", ELSE}, {"elseif", ELSEIF},
     {"end", END}, {"function", FUNCTION}, {"if", IF}, {"local", LOCAL},
     {"nil", NIL}, {"not", NOT}, {"or", OR}, {"repeat", REPEAT},
     {"return", RETURN}, {"then", THEN}, {"until", UNTIL}, {"while", WHILE}
 };

 void luaX_init (void)
 {
   int i;
   for (i=0; i<(sizeof(reserved)/sizeof(reserved[0])); i++) {
     TaggedString *ts = luaS_new(reserved[i].name);
     ts->head.marked = reserved[i].token;  /* reserved word  (always > 255) */
   }
 }


 static void firstline (LexState *LS)
 {
   int c = zgetc(LS->lex_z);
   if (c == '#') {
     LS->linenumber++;
     while ((c=zgetc(LS->lex_z)) != '\n' && c != EOZ) /* skip first line */;
   }
   zungetc(LS->lex_z);
 }


 void luaX_setinput (ZIO *z)
 {
   LexState *LS = L->lexstate;
   LS->current = '\n';
   LS->linelasttoken = 0;
   LS->linenumber = 0;
   LS->iflevel = 0;
   LS->ifstate[0].skip = 0;
   LS->ifstate[0].elsepart = 1;  /* to avoid a free $else */
   LS->lex_z = z;
   firstline(LS);
   luaL_resetbuffer();
 }


 /*
 ** =======================================================
 ** PRAGMAS
 ** =======================================================
 */

 #define PRAGMASIZE	20

 static void skipspace (LexState *LS)
 {
   while (LS->current == ' ' || LS->current == '\t' || LS->current == '\r')
     next(LS);
 }


 static int checkcond (char *buff)
 {
   static char *opts[] = {"nil", "1", NULL};
   int i = luaO_findstring(buff, opts);
   if (i >= 0) return i;
   else if (isalpha((unsigned char)buff[0]) || buff[0] == '_')
     return luaS_globaldefined(buff);
   else {
     luaY_syntaxerror("invalid $if condition", buff);
     return 0;  /* to avoid warnings */
   }
 }


 static void readname (LexState *LS, char *buff)
 {
   int i = 0;
   skipspace(LS);
   while (isalnum(LS->current) || LS->current == '_') {
     if (i >= PRAGMASIZE) {
       buff[PRAGMASIZE] = 0;
       luaY_syntaxerror("pragma too long", buff);
     }
     buff[i++] = LS->current;
     next(LS);
   }
   buff[i] = 0;
 }


 static void inclinenumber (LexState *LS);


 static void ifskip (LexState *LS)
 {
   while (LS->ifstate[LS->iflevel].skip) {
     if (LS->current == '\n')
       inclinenumber(LS);
     else if (LS->current == EOZ)
       luaY_syntaxerror("input ends inside a $if", "");
     else next(LS);
   }
 }


 static void inclinenumber (LexState *LS)
 {
   static char *pragmas [] =
     {"debug", "nodebug", "endinput", "end", "ifnot", "if", "else", NULL};
   next(LS);  /* skip '\n' */
   ++LS->linenumber;
   if (LS->current == '$') {  /* is a pragma? */
     char buff[PRAGMASIZE+1];
     int ifnot = 0;
     int skip = LS->ifstate[LS->iflevel].skip;
     next(LS);  /* skip $ */
     readname(LS, buff);
     switch (luaO_findstring(buff, pragmas)) {
       case 0:  /* debug */
         if (!skip) lua_debug = 1;
         break;
       case 1:  /* nodebug */
         if (!skip) lua_debug = 0;
         break;
       case 2:  /* endinput */
         if (!skip) {
           LS->current = EOZ;
           LS->iflevel = 0;  /* to allow $endinput inside a $if */
         }
         break;
       case 3:  /* end */
         if (LS->iflevel-- == 0)
           luaY_syntaxerror("unmatched $end", "$end");
         break;
       case 4:  /* ifnot */
         ifnot = 1;
         /* go through */
       case 5:  /* if */
         if (LS->iflevel == MAX_IFS-1)
           luaY_syntaxerror("too many nested $ifs", "$if");
         readname(LS, buff);
         LS->iflevel++;
         LS->ifstate[LS->iflevel].elsepart = 0;
         LS->ifstate[LS->iflevel].condition = checkcond(buff) ? !ifnot : ifnot;
         LS->ifstate[LS->iflevel].skip = skip || !LS->ifstate[LS->iflevel].condition;
         break;
       case 6:  /* else */
         if (LS->ifstate[LS->iflevel].elsepart)
           luaY_syntaxerror("unmatched $else", "$else");
         LS->ifstate[LS->iflevel].elsepart = 1;
         LS->ifstate[LS->iflevel].skip = LS->ifstate[LS->iflevel-1].skip ||
                                       LS->ifstate[LS->iflevel].condition;
         break;
       default:
         luaY_syntaxerror("unknown pragma", buff);
     }
     skipspace(LS);
     if (LS->current == '\n')  /* pragma must end with a '\n' ... */
       inclinenumber(LS);
     else if (LS->current != EOZ)  /* or eof */
       luaY_syntaxerror("invalid pragma format", buff);
     ifskip(LS);
   }
 }


 /*
 ** =======================================================
 ** LEXICAL ANALIZER
 ** =======================================================
 */


 #define save(c)	luaL_addchar(c)
 #define save_and_next(LS)  (save(LS->current), next(LS))


 char *luaX_lasttoken (void)
 {
   save(0);
   return luaL_buffer();
 }


 static int read_long_string (LexState *LS, YYSTYPE *l)
 {
   int cont = 0;
   while (1) {
     switch (LS->current) {
       case EOZ:
         save(0);
         return WRONGTOKEN;
       case '[':
         save_and_next(LS);
         if (LS->current == '[') {
           cont++;
           save_and_next(LS);
         }
         continue;
       case ']':
         save_and_next(LS);
         if (LS->current == ']') {
           if (cont == 0) goto endloop;
           cont--;
           save_and_next(LS);
         }
         continue;
       case '\n':
         save('\n');
         inclinenumber(LS);
         continue;
       default:
         save_and_next(LS);
     }
   } endloop:
   save_and_next(LS);  /* pass the second ']' */
   L->Mbuffer[L->Mbuffnext-2] = 0;  /* erases ']]' */
   l->pTStr = luaS_new(L->Mbuffbase+2);
   L->Mbuffer[L->Mbuffnext-2] = ']';  /* restores ']]' */
   return STRING;
 }


 /* to avoid warnings; this declaration cannot be public since YYSTYPE
 ** cannot be visible in llex.h (otherwise there is an error, since
 ** the parser body redefines it!)
 */
 int luaY_lex (YYSTYPE *l);
 int luaY_lex (YYSTYPE *l)
 {
   LexState *LS = L->lexstate;
   double a;
   luaL_resetbuffer();
   if (lua_debug)
     luaY_codedebugline(LS->linelasttoken);
   LS->linelasttoken = LS->linenumber;
   while (1) {
     switch (LS->current) {

       case ' ': case '\t': case '\r':  /* CR: to avoid problems with DOS */
         next(LS);
         continue;

       case '\n':
         inclinenumber(LS);
         LS->linelasttoken = LS->linenumber;
         continue;

       case '-':
         save_and_next(LS);
         if (LS->current != '-') return '-';
         do { next(LS); } while (LS->current != '\n' && LS->current != EOZ);
         luaL_resetbuffer();
         continue;

       case '[':
         save_and_next(LS);
         if (LS->current != '[') return '[';
         else {
           save_and_next(LS);  /* pass the second '[' */
           return read_long_string(LS, l);
         }

       case '=':
         save_and_next(LS);
         if (LS->current != '=') return '=';
         else { save_and_next(LS); return EQ; }

       case '<':
         save_and_next(LS);
         if (LS->current != '=') return '<';
         else { save_and_next(LS); return LE; }

       case '>':
         save_and_next(LS);
         if (LS->current != '=') return '>';
         else { save_and_next(LS); return GE; }

       case '~':
         save_and_next(LS);
         if (LS->current != '=') return '~';
         else { save_and_next(LS); return NE; }

       case '"':
       case '\'': {
         int del = LS->current;
         save_and_next(LS);
         while (LS->current != del) {
           switch (LS->current) {
             case EOZ:
             case '\n':
               save(0);
               return WRONGTOKEN;
             case '\\':
               next(LS);  /* do not save the '\' */
               switch (LS->current) {
                 case 'n': save('\n'); next(LS); break;
                 case 't': save('\t'); next(LS); break;
                 case 'r': save('\r'); next(LS); break;
                 case '\n': save('\n'); inclinenumber(LS); break;
                 default : save_and_next(LS); break;
               }
               break;
             default:
               save_and_next(LS);
           }
         }
         next(LS);  /* skip delimiter */
         save(0);
         l->pTStr = luaS_new(L->Mbuffbase+1);
         L->Mbuffer[L->Mbuffnext-1] = del;  /* restore delimiter */
         return STRING;
       }

       case '.':
         save_and_next(LS);
         if (LS->current == '.')
         {
           save_and_next(LS);
           if (LS->current == '.')
           {
             save_and_next(LS);
             return DOTS;   /* ... */
           }
           else return CONC;   /* .. */
         }
         else if (!isdigit(LS->current)) return '.';
         /* LS->current is a digit: goes through to number */
 	a=0.0;
         goto fraction;

       case '0': case '1': case '2': case '3': case '4':
       case '5': case '6': case '7': case '8': case '9':
 	a=0.0;
         do {
           a=10.0*a+(LS->current-'0');
           save_and_next(LS);
         } while (isdigit(LS->current));
         if (LS->current == '.') {
           save_and_next(LS);
           if (LS->current == '.') {
             save(0);
             luaY_error(
               "ambiguous syntax (decimal point x string concatenation)");
           }
         }
       fraction:
 	{ double da=0.1;
 	  while (isdigit(LS->current))
 	  {
             a+=(LS->current-'0')*da;
             da/=10.0;
             save_and_next(LS);
           }
           if (toupper(LS->current) == 'E') {
 	    int e=0;
 	    int neg;
 	    double ea;
             save_and_next(LS);
 	    neg=(LS->current=='-');
             if (LS->current == '+' || LS->current == '-') save_and_next(LS);
             if (!isdigit(LS->current)) {
               save(0); return WRONGTOKEN; }
             do {
               e=10.0*e+(LS->current-'0');
               save_and_next(LS);
             } while (isdigit(LS->current));
 	    for (ea=neg?0.1:10.0; e>0; e>>=1)
 	    {
 	      if (e & 1) a*=ea;
 	      ea*=ea;
 	    }
           }
           l->vReal = a;
           return NUMBER;
         }

       case EOZ:
         save(0);
         if (LS->iflevel > 0)
           luaY_syntaxerror("input ends inside a $if", "");
         return 0;

       default:
         if (LS->current != '_' && !isalpha(LS->current)) {
           int c = LS->current;
           save_and_next(LS);
           return c;
         }
         else {  /* identifier or reserved word */
           TaggedString *ts;
           do {
             save_and_next(LS);
           } while (isalnum(LS->current) || LS->current == '_');
           save(0);
           ts = luaS_new(L->Mbuffbase);
           if (ts->head.marked > 255)
             return ts->head.marked;  /* reserved word */
           l->pTStr = ts;
           return NAME;
         }
     }
   }
 }
	/*
	** $Id: llex.c,v 1.12 1997/12/22 17:52:20 roberto Exp roberto $
	** Lexical Analizer
	** See Copyright Notice in lua.h
	*/


	#include <ctype.h>
	#include <string.h>

	#include "lauxlib.h"
	#include "llex.h"
	#include "lmem.h"
	#include "lobject.h"
	#include "lparser.h"
	#include "lstate.h"
	#include "lstring.h"
	#include "lstx.h"
	#include "luadebug.h"
	#include "lzio.h"



	int lua_debug=0;


	#define next(LS) (LS->current = zgetc(LS->lex_z))


	static struct {
	char *name;
	int token;
	} reserved [] = {
	{"and", AND}, {"do", DO}, {"else", ELSE}, {"elseif", ELSEIF},
	{"end", END}, {"function", FUNCTION}, {"if", IF}, {"local", LOCAL},
	{"nil", NIL}, {"not", NOT}, {"or", OR}, {"repeat", REPEAT},
	{"return", RETURN}, {"then", THEN}, {"until", UNTIL}, {"while", WHILE}
	};

	void luaX_init (void)
	{
	int i;
	for (i=0; i<(sizeof(reserved)/sizeof(reserved[0])); i++) {
	TaggedString *ts = luaS_new(reserved[i].name);
	ts->head.marked = reserved[i].token; /* reserved word (always > 255) */
	}
	}


	static void firstline (LexState *LS)
	{
	int c = zgetc(LS->lex_z);
	if (c == '#') {
	LS->linenumber++;
	while ((c=zgetc(LS->lex_z)) != '\n' && c != EOZ) /* skip first line */;
	}
	zungetc(LS->lex_z);
	}


	void luaX_setinput (ZIO *z)
	{
	LexState *LS = L->lexstate;
	LS->current = '\n';
	LS->linelasttoken = 0;
	LS->linenumber = 0;
	LS->iflevel = 0;
	LS->ifstate[0].skip = 0;
	LS->ifstate[0].elsepart = 1; /* to avoid a free $else */
	LS->lex_z = z;
	firstline(LS);
	luaL_resetbuffer();
	}



	/*
	** =======================================================
	** PRAGMAS
	** =======================================================
	*/

	#define PRAGMASIZE 20

	static void skipspace (LexState *LS)
	{
	while (LS->current == ' ' \|\| LS->current == '\t' \|\| LS->current == '\r')
	next(LS);
	}


	static int checkcond (char *buff)
	{
	static char *opts[] = {"nil", "1", NULL};
	int i = luaO_findstring(buff, opts);
	if (i >= 0) return i;
	else if (isalpha((unsigned char)buff[0]) \|\| buff[0] == '_')
	return luaS_globaldefined(buff);
	else {
	luaY_syntaxerror("invalid $if condition", buff);
	return 0; /* to avoid warnings */
	}
	}


	static void readname (LexState LS, char buff)
	{
	int i = 0;
	skipspace(LS);
	while (isalnum(LS->current) \|\| LS->current == '_') {
	if (i >= PRAGMASIZE) {
	buff[PRAGMASIZE] = 0;
	luaY_syntaxerror("pragma too long", buff);
	}
	buff[i++] = LS->current;
	next(LS);
	}
	buff[i] = 0;
	}


	static void inclinenumber (LexState *LS);


	static void ifskip (LexState *LS)
	{
	while (LS->ifstate[LS->iflevel].skip) {
	if (LS->current == '\n')
	inclinenumber(LS);
	else if (LS->current == EOZ)
	luaY_syntaxerror("input ends inside a $if", "");
	else next(LS);
	}
	}


	static void inclinenumber (LexState *LS)
	{
	static char *pragmas [] =
	{"debug", "nodebug", "endinput", "end", "ifnot", "if", "else", NULL};
	next(LS); /* skip '\n' */
	++LS->linenumber;
	if (LS->current == '$') { /* is a pragma? */
	char buff[PRAGMASIZE+1];
	int ifnot = 0;
	int skip = LS->ifstate[LS->iflevel].skip;
	next(LS); /* skip $ */
	readname(LS, buff);
	switch (luaO_findstring(buff, pragmas)) {
	case 0: /* debug */
	if (!skip) lua_debug = 1;
	break;
	case 1: /* nodebug */
	if (!skip) lua_debug = 0;
	break;
	case 2: /* endinput */
	if (!skip) {
	LS->current = EOZ;
	LS->iflevel = 0; /* to allow $endinput inside a $if */
	}
	break;
	case 3: /* end */
	if (LS->iflevel-- == 0)
	luaY_syntaxerror("unmatched $end", "$end");
	break;
	case 4: /* ifnot */
	ifnot = 1;
	/* go through */
	case 5: /* if */
	if (LS->iflevel == MAX_IFS-1)
	luaY_syntaxerror("too many nested $ifs", "$if");
	readname(LS, buff);
	LS->iflevel++;
	LS->ifstate[LS->iflevel].elsepart = 0;
	LS->ifstate[LS->iflevel].condition = checkcond(buff) ? !ifnot : ifnot;
	LS->ifstate[LS->iflevel].skip = skip \|\| !LS->ifstate[LS->iflevel].condition;
	break;
	case 6: /* else */
	if (LS->ifstate[LS->iflevel].elsepart)
	luaY_syntaxerror("unmatched $else", "$else");
	LS->ifstate[LS->iflevel].elsepart = 1;
	LS->ifstate[LS->iflevel].skip = LS->ifstate[LS->iflevel-1].skip \|\|
	LS->ifstate[LS->iflevel].condition;
	break;
	default:
	luaY_syntaxerror("unknown pragma", buff);
	}
	skipspace(LS);
	if (LS->current == '\n') /* pragma must end with a '\n' ... */
	inclinenumber(LS);
	else if (LS->current != EOZ) /* or eof */
	luaY_syntaxerror("invalid pragma format", buff);
	ifskip(LS);
	}
	}


	/*
	** =======================================================
	** LEXICAL ANALIZER
	** =======================================================
	*/



	#define save(c) luaL_addchar(c)
	#define save_and_next(LS) (save(LS->current), next(LS))


	char *luaX_lasttoken (void)
	{
	save(0);
	return luaL_buffer();
	}


	static int read_long_string (LexState LS, YYSTYPE l)
	{
	int cont = 0;
	while (1) {
	switch (LS->current) {
	case EOZ:
	save(0);
	return WRONGTOKEN;
	case '[':
	save_and_next(LS);
	if (LS->current == '[') {
	cont++;
	save_and_next(LS);
	}
	continue;
	case ']':
	save_and_next(LS);
	if (LS->current == ']') {
	if (cont == 0) goto endloop;
	cont--;
	save_and_next(LS);
	}
	continue;
	case '\n':
	save('\n');
	inclinenumber(LS);
	continue;
	default:
	save_and_next(LS);
	}
	} endloop:
	save_and_next(LS); /* pass the second ']' */
	L->Mbuffer[L->Mbuffnext-2] = 0; /* erases ']]' */
	l->pTStr = luaS_new(L->Mbuffbase+2);
	L->Mbuffer[L->Mbuffnext-2] = ']'; /* restores ']]' */
	return STRING;
	}


	/* to avoid warnings; this declaration cannot be public since YYSTYPE
	** cannot be visible in llex.h (otherwise there is an error, since
	** the parser body redefines it!)
	*/
	int luaY_lex (YYSTYPE *l);
	int luaY_lex (YYSTYPE *l)
	{
	LexState *LS = L->lexstate;
	double a;
	luaL_resetbuffer();
	if (lua_debug)
	luaY_codedebugline(LS->linelasttoken);
	LS->linelasttoken = LS->linenumber;
	while (1) {
	switch (LS->current) {

	case ' ': case '\t': case '\r': /* CR: to avoid problems with DOS */
	next(LS);
	continue;

	case '\n':
	inclinenumber(LS);
	LS->linelasttoken = LS->linenumber;
	continue;

	case '-':
	save_and_next(LS);
	if (LS->current != '-') return '-';
	do { next(LS); } while (LS->current != '\n' && LS->current != EOZ);
	luaL_resetbuffer();
	continue;

	case '[':
	save_and_next(LS);
	if (LS->current != '[') return '[';
	else {
	save_and_next(LS); /* pass the second '[' */
	return read_long_string(LS, l);
	}

	case '=':
	save_and_next(LS);
	if (LS->current != '=') return '=';
	else { save_and_next(LS); return EQ; }

	case '<':
	save_and_next(LS);
	if (LS->current != '=') return '<';
	else { save_and_next(LS); return LE; }

	case '>':
	save_and_next(LS);
	if (LS->current != '=') return '>';
	else { save_and_next(LS); return GE; }

	case '~':
	save_and_next(LS);
	if (LS->current != '=') return '~';
	else { save_and_next(LS); return NE; }

	case '"':
	case '\'': {
	int del = LS->current;
	save_and_next(LS);
	while (LS->current != del) {
	switch (LS->current) {
	case EOZ:
	case '\n':
	save(0);
	return WRONGTOKEN;
	case '\\':
	next(LS); /* do not save the '\' */
	switch (LS->current) {
	case 'n': save('\n'); next(LS); break;
	case 't': save('\t'); next(LS); break;
	case 'r': save('\r'); next(LS); break;
	case '\n': save('\n'); inclinenumber(LS); break;
	default : save_and_next(LS); break;
	}
	break;
	default:
	save_and_next(LS);
	}
	}
	next(LS); /* skip delimiter */
	save(0);
	l->pTStr = luaS_new(L->Mbuffbase+1);
	L->Mbuffer[L->Mbuffnext-1] = del; /* restore delimiter */
	return STRING;
	}

	case '.':
	save_and_next(LS);
	if (LS->current == '.')
	{
	save_and_next(LS);
	if (LS->current == '.')
	{
	save_and_next(LS);
	return DOTS; /* ... */
	}
	else return CONC; /* .. */
	}
	else if (!isdigit(LS->current)) return '.';
	/* LS->current is a digit: goes through to number */
	a=0.0;
	goto fraction;

	case '0': case '1': case '2': case '3': case '4':
	case '5': case '6': case '7': case '8': case '9':
	a=0.0;
	do {
	a=10.0*a+(LS->current-'0');
	save_and_next(LS);
	} while (isdigit(LS->current));
	if (LS->current == '.') {
	save_and_next(LS);
	if (LS->current == '.') {
	save(0);
	luaY_error(
	"ambiguous syntax (decimal point x string concatenation)");
	}
	}
	fraction:
	{ double da=0.1;
	while (isdigit(LS->current))
	{
	a+=(LS->current-'0')*da;
	da/=10.0;
	save_and_next(LS);
	}
	if (toupper(LS->current) == 'E') {
	int e=0;
	int neg;
	double ea;
	save_and_next(LS);
	neg=(LS->current=='-');
	if (LS->current == '+' \|\| LS->current == '-') save_and_next(LS);
	if (!isdigit(LS->current)) {
	save(0); return WRONGTOKEN; }
	do {
	e=10.0*e+(LS->current-'0');
	save_and_next(LS);
	} while (isdigit(LS->current));
	for (ea=neg?0.1:10.0; e>0; e>>=1)
	{
	if (e & 1) a*=ea;
	ea*=ea;
	}
	}
	l->vReal = a;
	return NUMBER;
	}

	case EOZ:
	save(0);
	if (LS->iflevel > 0)
	luaY_syntaxerror("input ends inside a $if", "");
	return 0;

	default:
	if (LS->current != '_' && !isalpha(LS->current)) {
	int c = LS->current;
	save_and_next(LS);
	return c;
	}
	else { /* identifier or reserved word */
	TaggedString *ts;
	do {
	save_and_next(LS);
	} while (isalnum(LS->current) \|\| LS->current == '_');
	save(0);
	ts = luaS_new(L->Mbuffbase);
	if (ts->head.marked > 255)
	return ts->head.marked; /* reserved word */
	l->pTStr = ts;
	return NAME;
	}
	}
	}
	}