/*
** Read a number: first reads a valid prefix of a numeral into a buffer.
** Then it calls 'lua_stringtonumber' to check whether the format is
** correct and to convert it to a Lua number
*/
static int read_number (lua_State *L, FILE *f) {
RN rn;
int count = 0;
int hex = 0;
char decp[2];
rn.f = f; rn.n = 0;
decp[0] = lua_getlocaledecpoint(); /* get decimal point from locale */
decp[1] = '.'; /* always accept a dot */
l_lockfile(rn.f);
do { rn.c = l_getc(rn.f); } while (isspace(rn.c)); /* skip spaces */
test2(&rn, "-+"); /* optional signal */
if (test2(&rn, "00")) {
if (test2(&rn, "xX")) hex = 1; /* numeral is hexadecimal */
else count = 1; /* count initial '0' as a valid digit */
}
count += readdigits(&rn, hex); /* integral part */
if (test2(&rn, decp)) /* decimal point? */
count += readdigits(&rn, hex); /* fractional part */
if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) { /* exponent mark? */
test2(&rn, "-+"); /* exponent signal */
readdigits(&rn, 0); /* exponent digits */
}
ungetc(rn.c, rn.f); /* unread look-ahead char */
l_unlockfile(rn.f);
rn.buff[rn.n] = '\0'; /* finish string */
if (lua_stringtonumber(L, rn.buff)) /* is this a valid number? */
return 1; /* ok */
else { /* invalid format */
lua_pushnil(L); /* "result" to be removed */
return 0; /* read fails */
}
}
static int num2straux (char *buff, int sz, lua_Number x) {
/* if 'inf' or 'NaN', format it like '%g' */
if (x != x || x == (lua_Number)HUGE_VAL || x == -(lua_Number)HUGE_VAL)
return l_sprintf(buff, sz, LUA_NUMBER_FMT, (LUAI_UACNUMBER)x);
else if (x == 0) { /* can be -0... */
/* create "0" or "-0" followed by exponent */
return l_sprintf(buff, sz, LUA_NUMBER_FMT "x0p+0", (LUAI_UACNUMBER)x);
}
else {
int e;
lua_Number m = l_mathop(frexp)(x, &e); /* 'x' fraction and exponent */
int n = 0; /* character count */
if (m < 0) { /* is number negative? */
buff[n++] = '-'; /* add sign */
m = -m; /* make it positive */
}
buff[n++] = '0'; buff[n++] = 'x'; /* add "0x" */
m = adddigit(buff, n++, m * (1 << L_NBFD)); /* add first digit */
e -= L_NBFD; /* this digit goes before the radix point */
if (m > 0) { /* more digits? */
buff[n++] = lua_getlocaledecpoint(); /* add radix point */
do { /* add as many digits as needed */
m = adddigit(buff, n++, m * 16);
} while (m > 0);
}
n += l_sprintf(buff + n, sz - n, "p%+d", e); /* add exponent */
lua_assert(n < sz);
return n;
}
}
static int num2straux (char *buff, lua_Number x) {
if (x != x || x == HUGE_VAL || x == -HUGE_VAL) /* inf or NaN? */
return sprintf(buff, LUA_NUMBER_FMT, x); /* equal to '%g' */
else if (x == 0) { /* can be -0... */
sprintf(buff, LUA_NUMBER_FMT, x);
strcat(buff, "x0p+0"); /* reuses '0/-0' from 'sprintf'... */
return (int)strlen(buff); /* Custom change: fixed 64-bit compilation warning */
}
else {
int e;
lua_Number m = l_mathop(frexp)(x, &e); /* 'x' fraction and exponent */
int n = 0; /* character count */
if (m < 0) { /* is number negative? */
buff[n++] = '-'; /* add signal */
m = -m; /* make it positive */
}
buff[n++] = '0'; buff[n++] = 'x'; /* add "0x" */
m = adddigit(buff, n++, m * (1 << L_NBFD)); /* add first digit */
e -= L_NBFD; /* this digit goes before the radix point */
if (m > 0) { /* more digits? */
buff[n++] = lua_getlocaledecpoint(); /* add radix point */
do { /* add as many digits as needed */
m = adddigit(buff, n++, m * 16);
} while (m > 0);
}
n += sprintf(buff + n, "p%+d", e); /* add exponent */
return n;
}
}
/*
** Ensures the 'buff' string uses a dot as the radix character.
*/
static void checkdp (char *buff, int nb) {
if (memchr(buff, '.', nb) == NULL) { /* no dot? */
char point = lua_getlocaledecpoint(); /* try locale point */
char *ppoint = (char*)memchr(buff, point, nb);
if (ppoint) *ppoint = '.'; /* change it to a dot */
}
}
/*
** in case of format error, try to change decimal point separator to
** the one defined in the current locale and check again
*/
static void trydecpoint (LexState *ls, TValue *o) {
char old = ls->decpoint;
ls->decpoint = lua_getlocaledecpoint();
buffreplace(ls, old, ls->decpoint); /* try new decimal separator */
if (!buff2num(ls->buff, o)) {
/* format error with correct decimal point: no more options */
buffreplace(ls, ls->decpoint, '.'); /* undo change (for error message) */
lexerror(ls, "malformed number", TK_FLT);
}
}
/*
** convert an hexadecimal numeric string to a number, following
** C99 specification for 'strtod'
*/
static lua_Number lua_strx2number (const char *s, char **endptr) {
int dot = lua_getlocaledecpoint();
lua_Number r = 0.0; /* result (accumulator) */
int sigdig = 0; /* number of significant digits */
int nosigdig = 0; /* number of non-significant digits */
int e = 0; /* exponent correction */
int neg; /* 1 if number is negative */
int hasdot = 0; /* true after seen a dot */
*endptr = cast(char *, s); /* nothing is valid yet */
while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
neg = isneg(&s); /* check signal */
if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */
return 0.0; /* invalid format (no '0x') */
for (s += 2; ; s++) { /* skip '0x' and read numeral */
if (*s == dot) {
if (hasdot) break; /* second dot? stop loop */
else hasdot = 1;
}
else if (lisxdigit(cast_uchar(*s))) {
if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */
nosigdig++;
else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */
r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
else e++; /* too many digits; ignore, but still count for exponent */
if (hasdot) e--; /* decimal digit? correct exponent */
}
else break; /* neither a dot nor a digit */
}
if (nosigdig + sigdig == 0) /* no digits? */
return 0.0; /* invalid format */
*endptr = cast(char *, s); /* valid up to here */
e *= 4; /* each digit multiplies/divides value by 2^4 */
if (*s == 'p' || *s == 'P') { /* exponent part? */
int exp1 = 0; /* exponent value */
int neg1; /* exponent signal */
s++; /* skip 'p' */
neg1 = isneg(&s); /* signal */
if (!lisdigit(cast_uchar(*s)))
return 0.0; /* invalid; must have at least one digit */
while (lisdigit(cast_uchar(*s))) /* read exponent */
exp1 = exp1 * 10 + *(s++) - '0';
if (neg1) exp1 = -exp1;
e += exp1;
*endptr = cast(char *, s); /* valid up to here */
}
/*
** Serialize a floating-point number in such a way that it can be
** scanned back by Lua. Use hexadecimal format for "common" numbers
** (to preserve precision); inf, -inf, and NaN are handled separately.
** (NaN cannot be expressed as a numeral, so we write '(0/0)' for it.)
*/
static int quotefloat (lua_State *L, char *buff, lua_Number n) {
const char *s; /* for the fixed representations */
if (n == (lua_Number)HUGE_VAL) /* inf? */
s = "1e9999";
else if (n == -(lua_Number)HUGE_VAL) /* -inf? */
s = "-1e9999";
else if (n != n) /* NaN? */
s = "(0/0)";
else { /* format number as hexadecimal */
int nb = lua_number2strx(L, buff, MAX_ITEM,
"%" LUA_NUMBER_FRMLEN "a", n);
/* ensures that 'buff' string uses a dot as the radix character */
if (memchr(buff, '.', nb) == NULL) { /* no dot? */
char point = lua_getlocaledecpoint(); /* try locale point */
char *ppoint = (char *)memchr(buff, point, nb);
if (ppoint) *ppoint = '.'; /* change it to a dot */
}
return nb;
}
/* for the fixed representations */
return l_sprintf(buff, MAX_ITEM, "%s", s);
}
