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NEW LL(1) PARSER

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This commit is contained in:
Roberto Ierusalimschy
1998-05-27 10:08:34 -03:00
parent abc6eac404
commit 7e59a8901d
6 changed files with 1442 additions and 1025 deletions
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138
llex.c
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@@ -1,5 +1,5 @@
/*
** $Id: llex.c,v 1.17 1998/03/09 17:22:49 roberto Exp roberto $
** $Id: llex.c,v 1.18 1998/03/20 14:18:18 roberto Exp roberto $
** Lexical Analizer
** See Copyright Notice in lua.h
*/
@@ -15,7 +15,6 @@
#include "lparser.h"
#include "lstate.h"
#include "lstring.h"
#include "lstx.h"
#include "luadebug.h"
#include "lzio.h"
@@ -27,26 +26,56 @@ 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}
};
#define save(c) luaL_addchar(c)
#define save_and_next(LS) (save(LS->current), next(LS))
char *reserved [] = {"and", "do", "else", "elseif", "end", "function",
"if", "local", "nil", "not", "or", "repeat", "return", "then",
"until", "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) */
TaggedString *ts = luaS_new(reserved[i]);
ts->head.marked = FIRST_RESERVED+i; /* reserved word (always > 255) */
}
}
void luaX_syntaxerror (LexState *ls, char *s, char *token) {
if (token[0] == 0)
token = "<eof>";
luaL_verror("%.100s;\n last token read: `%.50s' at line %d in file %.50s",
s, token, ls->linenumber, zname(ls->lex_z));
}
void luaX_error (LexState *ls, char *s) {
save(0);
luaX_syntaxerror(ls, s, luaL_buffer());
}
void luaX_token2str (LexState *ls, int token, char *s) {
if (token < 255) {
s[0] = token;
s[1] = 0;
}
else
strcpy(s, reserved[token-FIRST_RESERVED]);
}
static void luaX_invalidchar (LexState *ls, int c) {
char buff[10];
sprintf(buff, "0x%X", c);
luaX_syntaxerror(ls, "invalid control char", buff);
}
static void firstline (LexState *LS)
{
int c = zgetc(LS->lex_z);
@@ -56,16 +85,15 @@ static void firstline (LexState *LS)
}
void luaX_setinput (ZIO *z)
void luaX_setinput (LexState *LS, 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;
LS->fs = NULL;
firstline(LS);
luaL_resetbuffer();
}
@@ -87,7 +115,7 @@ static void skipspace (LexState *LS)
}
static int checkcond (char *buff)
static int checkcond (LexState *LS, char *buff)
{
static char *opts[] = {"nil", "1", NULL};
int i = luaO_findstring(buff, opts);
@@ -95,7 +123,7 @@ static int checkcond (char *buff)
else if (isalpha((unsigned char)buff[0]) || buff[0] == '_')
return luaS_globaldefined(buff);
else {
luaY_syntaxerror("invalid $if condition", buff);
luaX_syntaxerror(LS, "invalid $if condition", buff);
return 0; /* to avoid warnings */
}
}
@@ -108,7 +136,7 @@ static void readname (LexState *LS, char *buff)
while (isalnum(LS->current) || LS->current == '_') {
if (i >= PRAGMASIZE) {
buff[PRAGMASIZE] = 0;
luaY_syntaxerror("pragma too long", buff);
luaX_syntaxerror(LS, "pragma too long", buff);
}
buff[i++] = LS->current;
next(LS);
@@ -126,7 +154,7 @@ static void ifskip (LexState *LS)
if (LS->current == '\n')
inclinenumber(LS);
else if (LS->current == EOZ)
luaY_error("input ends inside a $if");
luaX_error(LS, "input ends inside a $if");
else next(LS);
}
}
@@ -159,35 +187,35 @@ static void inclinenumber (LexState *LS)
break;
case 3: /* end */
if (LS->iflevel-- == 0)
luaY_syntaxerror("unmatched $end", "$end");
luaX_syntaxerror(LS, "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");
luaX_syntaxerror(LS, "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].condition = checkcond(LS, 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");
luaX_syntaxerror(LS, "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);
luaX_syntaxerror(LS, "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);
luaX_syntaxerror(LS, "invalid pragma format", buff);
ifskip(LS);
}
}
@@ -201,25 +229,16 @@ static void inclinenumber (LexState *LS)
#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)
static int read_long_string (LexState *LS)
{
int cont = 0;
while (1) {
switch (LS->current) {
case EOZ:
luaY_error("unfinished long string");
return 0; /* to avoid warnings */
luaX_error(LS, "unfinished long string");
return EOS; /* to avoid warnings */
case '[':
save_and_next(LS);
if (LS->current == '[') {
@@ -244,25 +263,15 @@ static int read_long_string (LexState *LS, YYSTYPE *l)
}
} endloop:
save_and_next(LS); /* pass the second ']' */
l->pTStr = luaS_newlstr(L->Mbuffbase+2,
LS->seminfo.ts = luaS_newlstr(L->Mbuffbase+2,
L->Mbuffnext-(L->Mbuffbase-L->Mbuffer)-4);
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;
int luaX_lex (LexState *LS) {
double a;
luaL_resetbuffer();
if (lua_debug)
luaY_codedebugline(LS->linelasttoken);
LS->linelasttoken = LS->linenumber;
while (1) {
switch (LS->current) {
@@ -272,7 +281,6 @@ int luaY_lex (YYSTYPE *l)
case '\n':
inclinenumber(LS);
LS->linelasttoken = LS->linenumber;
continue;
case '-':
@@ -287,7 +295,7 @@ int luaY_lex (YYSTYPE *l)
if (LS->current != '[') return '[';
else {
save_and_next(LS); /* pass the second '[' */
return read_long_string(LS, l);
return read_long_string(LS);
}
case '=':
@@ -318,8 +326,8 @@ int luaY_lex (YYSTYPE *l)
switch (LS->current) {
case EOZ:
case '\n':
luaY_error("unfinished string");
return 0; /* to avoid warnings */
luaX_error(LS, "unfinished string");
return EOS; /* to avoid warnings */
case '\\':
next(LS); /* do not save the '\' */
switch (LS->current) {
@@ -345,13 +353,13 @@ int luaY_lex (YYSTYPE *l)
next(LS);
} while (++i<3 && isdigit(LS->current));
if (c >= 256)
luaY_error("escape sequence too large");
luaX_error(LS, "escape sequence too large");
save(c);
}
else {
save('\\');
save(LS->current);
luaY_error("invalid escape sequence");
luaX_error(LS, "invalid escape sequence");
}
break;
}
@@ -362,7 +370,7 @@ int luaY_lex (YYSTYPE *l)
}
}
save_and_next(LS); /* skip delimiter */
l->pTStr = luaS_newlstr(L->Mbuffbase+1,
LS->seminfo.ts = luaS_newlstr(L->Mbuffbase+1,
L->Mbuffnext-(L->Mbuffbase-L->Mbuffer)-2);
return STRING;
}
@@ -395,7 +403,7 @@ int luaY_lex (YYSTYPE *l)
save_and_next(LS);
if (LS->current == '.') {
save('.');
luaY_error(
luaX_error(LS,
"ambiguous syntax (decimal point x string concatenation)");
}
}
@@ -415,7 +423,7 @@ int luaY_lex (YYSTYPE *l)
neg = (LS->current=='-');
if (LS->current == '+' || LS->current == '-') save_and_next(LS);
if (!isdigit(LS->current))
luaY_error("invalid numeral format");
luaX_error(LS, "invalid numeral format");
do {
e = 10.0*e + (LS->current-'0');
save_and_next(LS);
@@ -426,18 +434,20 @@ int luaY_lex (YYSTYPE *l)
ea *= ea;
}
}
l->vReal = a;
LS->seminfo.r = a;
return NUMBER;
}
case EOZ:
if (LS->iflevel > 0)
luaY_error("input ends inside a $if");
return 0;
luaX_error(LS, "input ends inside a $if");
return EOS;
default:
if (LS->current != '_' && !isalpha(LS->current)) {
int c = LS->current;
if (iscntrl(c))
luaX_invalidchar(LS, c);
save_and_next(LS);
return c;
}
@@ -448,9 +458,9 @@ int luaY_lex (YYSTYPE *l)
} while (isalnum(LS->current) || LS->current == '_');
save(0);
ts = luaS_new(L->Mbuffbase);
if (ts->head.marked > 255)
if (ts->head.marked >= 'A')
return ts->head.marked; /* reserved word */
l->pTStr = ts;
LS->seminfo.ts = ts;
return NAME;
}
}