blob: 8740f1e2a8f61b3c2580949a7542df6d2f634ea5 [file] [log] [blame]
char *rcs_lex = "$Id: lex.c,v 2.46 1997/04/07 14:48:53 roberto Exp roberto $";
#include <ctype.h>
#include <string.h>
#include "auxlib.h"
#include "luamem.h"
#include "tree.h"
#include "table.h"
#include "lex.h"
#include "inout.h"
#include "luadebug.h"
#include "parser.h"
#define MINBUFF 250
#define next() (current = input())
#define save(x) (yytext[tokensize++] = (x))
#define save_and_next() (save(current), next())
static int current; /* look ahead character */
static Input input; /* input function */
#define MAX_IFS 10
/* "ifstate" keeps the state of each nested $if the lexical is
** dealing with. The first bit indicates whether the $if condition
** is false or true. The second bit indicates whether the lexical is
** inside the "then" part (0) or the "else" part (2)
*/
static int ifstate[MAX_IFS]; /* 0 => then part - condition false */
/* 1 => then part - condition true */
/* 2 => else part - condition false */
/* 3 => else part - condition true */
static int iflevel; /* level of nested $if's */
void lua_setinput (Input fn)
{
current = '\n';
lua_linenumber = 0;
iflevel = 0;
input = fn;
}
static void luaI_auxsyntaxerror (char *s)
{
luaL_verror("%s;\n> at line %d in file %s",
s, lua_linenumber, lua_parsedfile);
}
static void luaI_auxsynterrbf (char *s, char *token)
{
if (token[0] == 0)
token = "<eof>";
luaL_verror("%s;\n> last token read: \"%s\" at line %d in file %s",
s, token, lua_linenumber, lua_parsedfile);
}
void luaI_syntaxerror (char *s)
{
luaI_auxsynterrbf(s, luaI_buffer(1));
}
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} };
#define RESERVEDSIZE (sizeof(reserved)/sizeof(reserved[0]))
void luaI_addReserved (void)
{
int i;
for (i=0; i<RESERVEDSIZE; i++)
{
TaggedString *ts = lua_createstring(reserved[i].name);
ts->marked = reserved[i].token; /* reserved word (always > 255) */
}
}
/*
** Pragma handling
*/
#define PRAGMASIZE 20
static void skipspace (void)
{
while (current == ' ' || current == '\t') next();
}
static int checkcond (char *buff)
{
if (strcmp(buff, "nil") == 0)
return 0;
else if (strcmp(buff, "1") == 0)
return 1;
else if (isalpha((unsigned char)buff[0]))
return luaI_globaldefined(buff);
else {
luaI_auxsynterrbf("invalid $if condition", buff);
return 0; /* to avoid warnings */
}
}
static void readname (char *buff)
{
int i = 0;
skipspace();
while (isalnum((unsigned char)current)) {
if (i >= PRAGMASIZE) {
buff[PRAGMASIZE] = 0;
luaI_auxsynterrbf("pragma too long", buff);
}
buff[i++] = current;
next();
}
buff[i] = 0;
}
static void inclinenumber (void);
static void ifskip (int thisiflevel)
{
while (iflevel > thisiflevel &&
(ifstate[thisiflevel] == 0 || ifstate[thisiflevel] == 3)) {
if (current == '\n')
inclinenumber();
else if (current == 0)
luaI_auxsyntaxerror("input ends inside a $if");
else next();
}
}
static void inclinenumber (void)
{
static char *pragmas [] =
{"debug", "nodebug", "end", "ifnot", "if", "else", NULL};
next(); /* skip '\n' */
++lua_linenumber;
if (current == '$') { /* is a pragma? */
char buff[PRAGMASIZE+1];
int ifnot = 0;
next(); /* skip $ */
readname(buff);
switch (luaI_findstring(buff, pragmas)) {
case 0: /* debug */
lua_debug = 1;
break;
case 1: /* nodebug */
lua_debug = 0;
break;
case 2: /* end */
if (--iflevel < 0)
luaI_auxsyntaxerror("unmatched $endif");
break;
case 3: /* ifnot */
ifnot = 1;
/* go through */
case 4: /* if */
if (iflevel == MAX_IFS)
luaI_auxsyntaxerror("too many nested `$ifs'");
readname(buff);
ifstate[iflevel++] = checkcond(buff) ? !ifnot : ifnot;
break;
case 5: /* else */
if (iflevel <= 0 || (ifstate[iflevel-1] & 2))
luaI_auxsyntaxerror("unmatched $else");
ifstate[iflevel-1] = ifstate[iflevel-1] | 2;
break;
default:
luaI_auxsynterrbf("invalid pragma", buff);
}
skipspace();
if (current == '\n') /* pragma must end with a '\n' */
inclinenumber();
else if (current != 0) /* or eof */
luaI_auxsyntaxerror("invalid pragma format");
if (iflevel > 0)
ifskip(iflevel-1);
}
}
static int read_long_string (char *yytext, int buffsize)
{
int cont = 0;
int tokensize = 2; /* '[[' already stored */
while (1)
{
if (buffsize-tokensize <= 2) /* may read more than 1 char in one cicle */
yytext = luaI_buffer(buffsize *= 2);
switch (current)
{
case 0:
save(0);
return WRONGTOKEN;
case '[':
save_and_next();
if (current == '[')
{
cont++;
save_and_next();
}
continue;
case ']':
save_and_next();
if (current == ']')
{
if (cont == 0) goto endloop;
cont--;
save_and_next();
}
continue;
case '\n':
save('\n');
inclinenumber();
continue;
default:
save_and_next();
}
} endloop:
save_and_next(); /* pass the second ']' */
yytext[tokensize-2] = 0; /* erases ']]' */
luaY_lval.vWord = luaI_findconstantbyname(yytext+2);
yytext[tokensize-2] = ']'; /* restores ']]' */
save(0);
return STRING;
}
int luaY_lex (void)
{
static int linelasttoken = 0;
double a;
int buffsize = MINBUFF;
char *yytext = luaI_buffer(buffsize);
yytext[1] = yytext[2] = yytext[3] = 0;
if (lua_debug)
luaI_codedebugline(linelasttoken);
linelasttoken = lua_linenumber;
while (1)
{
int tokensize = 0;
switch (current)
{
case '\n':
inclinenumber();
linelasttoken = lua_linenumber;
continue;
case ' ': case '\t': case '\r': /* CR: to avoid problems with DOS */
next();
continue;
case '-':
save_and_next();
if (current != '-') return '-';
do { next(); } while (current != '\n' && current != 0);
continue;
case '[':
save_and_next();
if (current != '[') return '[';
else
{
save_and_next(); /* pass the second '[' */
return read_long_string(yytext, buffsize);
}
case '=':
save_and_next();
if (current != '=') return '=';
else { save_and_next(); return EQ; }
case '<':
save_and_next();
if (current != '=') return '<';
else { save_and_next(); return LE; }
case '>':
save_and_next();
if (current != '=') return '>';
else { save_and_next(); return GE; }
case '~':
save_and_next();
if (current != '=') return '~';
else { save_and_next(); return NE; }
case '"':
case '\'':
{
int del = current;
save_and_next();
while (current != del)
{
if (buffsize-tokensize <= 2) /* may read more than 1 char in one cicle */
yytext = luaI_buffer(buffsize *= 2);
switch (current)
{
case 0:
case '\n':
save(0);
return WRONGTOKEN;
case '\\':
next(); /* do not save the '\' */
switch (current)
{
case 'n': save('\n'); next(); break;
case 't': save('\t'); next(); break;
case 'r': save('\r'); next(); break;
case '\n': save('\n'); inclinenumber(); break;
default : save_and_next(); break;
}
break;
default:
save_and_next();
}
}
next(); /* skip delimiter */
save(0);
luaY_lval.vWord = luaI_findconstantbyname(yytext+1);
tokensize--;
save(del); save(0); /* restore delimiter */
return STRING;
}
case 'a': case 'b': case 'c': case 'd': case 'e':
case 'f': case 'g': case 'h': case 'i': case 'j':
case 'k': case 'l': case 'm': case 'n': case 'o':
case 'p': case 'q': case 'r': case 's': case 't':
case 'u': case 'v': case 'w': case 'x': case 'y':
case 'z':
case 'A': case 'B': case 'C': case 'D': case 'E':
case 'F': case 'G': case 'H': case 'I': case 'J':
case 'K': case 'L': case 'M': case 'N': case 'O':
case 'P': case 'Q': case 'R': case 'S': case 'T':
case 'U': case 'V': case 'W': case 'X': case 'Y':
case 'Z':
case '_':
{
TaggedString *ts;
do {
save_and_next();
} while (isalnum((unsigned char)current) || current == '_');
save(0);
ts = lua_createstring(yytext);
if (ts->marked > 2)
return ts->marked; /* reserved word */
luaY_lval.pTStr = ts;
ts->marked = 2; /* avoid GC */
return NAME;
}
case '.':
save_and_next();
if (current == '.')
{
save_and_next();
if (current == '.')
{
save_and_next();
return DOTS; /* ... */
}
else return CONC; /* .. */
}
else if (!isdigit((unsigned char)current)) return '.';
/* 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+(current-'0');
save_and_next();
} while (isdigit((unsigned char)current));
if (current == '.') {
save_and_next();
if (current == '.')
luaI_syntaxerror(
"ambiguous syntax (decimal point x string concatenation)");
}
fraction:
{ double da=0.1;
while (isdigit((unsigned char)current))
{
a+=(current-'0')*da;
da/=10.0;
save_and_next();
}
if (current == 'e' || current == 'E')
{
int e=0;
int neg;
double ea;
save_and_next();
neg=(current=='-');
if (current == '+' || current == '-') save_and_next();
if (!isdigit((unsigned char)current)) {
save(0); return WRONGTOKEN; }
do {
e=10.0*e+(current-'0');
save_and_next();
} while (isdigit((unsigned char)current));
for (ea=neg?0.1:10.0; e>0; e>>=1)
{
if (e & 1) a*=ea;
ea*=ea;
}
}
luaY_lval.vFloat = a;
save(0);
return NUMBER;
}
case 0:
save(0);
if (iflevel > 0)
luaI_syntaxerror("missing $endif");
return 0;
default:
save_and_next();
return yytext[0];
}
}
}