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new function "luaO_str2d" to convert strings to numbers, because

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old "lex" algorithm had aproximation errors, but strtod (and atof
and scanf) are too slow.
This commit is contained in:
Roberto Ierusalimschy
1998-12-27 18:25:20 -02:00
parent d2de2d5eda
commit 4c94d8cc2c
4 changed files with 108 additions and 76 deletions
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67
llex.c
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@@ -1,5 +1,5 @@
/*
** $Id: llex.c,v 1.24 1998/07/24 18:02:38 roberto Exp roberto $
** $Id: llex.c,v 1.25 1998/12/03 15:45:15 roberto Exp $
** Lexical Analizer
** See Copyright Notice in lua.h
*/
@@ -46,7 +46,7 @@ void luaX_init (void)
void luaX_syntaxerror (LexState *ls, char *s, char *token) {
if (token[0] == 0)
if (token[0] == '\0')
token = "<eof>";
luaL_verror("%.100s;\n last token read: `%.50s' at line %d in chunk `%.50s'",
s, token, ls->linenumber, zname(ls->lex_z));
@@ -54,7 +54,7 @@ void luaX_syntaxerror (LexState *ls, char *s, char *token) {
void luaX_error (LexState *ls, char *s) {
save(0);
save('\0');
luaX_syntaxerror(ls, s, luaL_buffer());
}
@@ -62,7 +62,7 @@ void luaX_error (LexState *ls, char *s) {
void luaX_token2str (int token, char *s) {
if (token < 255) {
s[0] = token;
s[1] = 0;
s[1] = '\0';
}
else
strcpy(s, reserved[token-FIRST_RESERVED]);
@@ -221,6 +221,7 @@ static void inclinenumber (LexState *LS)
}
/*
** =======================================================
** LEXICAL ANALIZER
@@ -229,10 +230,7 @@ static void inclinenumber (LexState *LS)
static int read_long_string (LexState *LS)
{
static int read_long_string (LexState *LS) {
int cont = 0;
for (;;) {
switch (LS->current) {
@@ -262,7 +260,7 @@ static int read_long_string (LexState *LS)
save_and_next(LS);
}
} endloop:
save_and_next(LS); /* pass the second ']' */
save_and_next(LS); /* skip the second ']' */
LS->seminfo.ts = luaS_newlstr(L->Mbuffbase+2,
L->Mbuffnext-(L->Mbuffbase-L->Mbuffer)-4);
return STRING;
@@ -270,7 +268,6 @@ static int read_long_string (LexState *LS)
int luaX_lex (LexState *LS) {
double a;
luaL_resetbuffer();
for (;;) {
switch (LS->current) {
@@ -347,7 +344,7 @@ int luaX_lex (LexState *LS) {
c = 10*c + (LS->current-'0');
next(LS);
} while (++i<3 && isdigit(LS->current));
if (c >= 256)
if (c > (unsigned char)c)
luaX_error(LS, "escape sequence too large");
save(c);
}
@@ -382,15 +379,11 @@ int luaX_lex (LexState *LS) {
else return CONC; /* .. */
}
else if (!isdigit(LS->current)) return '.';
/* LS->current is a digit: goes through to number */
a=0.0;
goto fraction;
goto fraction; /* LS->current is a digit: goes through to number */
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 == '.') {
@@ -402,35 +395,19 @@ int luaX_lex (LexState *LS) {
}
}
fraction:
{ double da=0.1;
while (isdigit(LS->current))
{
a += (LS->current-'0')*da;
da /= 10.0;
while (isdigit(LS->current))
save_and_next(LS);
if (toupper(LS->current) == 'E') {
save_and_next(LS); /* read 'E' */
save_and_next(LS); /* read '+', '-' or first digit */
while (isdigit(LS->current))
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))
luaX_error(LS, "invalid numeral format");
do {
e = 10*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;
}
}
LS->seminfo.r = a;
return NUMBER;
}
save('\0');
LS->seminfo.r = luaO_str2d(L->Mbuffbase);
if (LS->seminfo.r < 0)
luaX_error(LS, "invalid numeric format");
return NUMBER;
case EOZ:
if (LS->iflevel > 0)
@@ -450,9 +427,9 @@ int luaX_lex (LexState *LS) {
do {
save_and_next(LS);
} while (isalnum(LS->current) || LS->current == '_');
save(0);
save('\0');
ts = luaS_new(L->Mbuffbase);
if (ts->head.marked >= 'A')
if (ts->head.marked >= FIRST_RESERVED)
return ts->head.marked; /* reserved word */
LS->seminfo.ts = ts;
return NAME;