/*
** this function is quite liberal in what it accepts, as 'luaO_str2num'
** will reject ill-formed numerals.
*/
static int read_numeral (LexState *ls, SemInfo *seminfo) {
TValue obj;
const char *expo = "Ee";
int first = ls->current;
lua_assert(lisdigit(ls->current));
save_and_next(ls);
if (first == '0' && check_next2(ls, "xX")) /* hexadecimal? */
expo = "Pp";
for (;;) {
if (check_next2(ls, expo)) /* exponent part? */
check_next2(ls, "-+"); /* optional exponent sign */
if (lisxdigit(ls->current))
save_and_next(ls);
else if (ls->current == '.')
save_and_next(ls);
else break;
}
save(ls, '\0');
if (luaO_str2num(luaZ_buffer(ls->buff), &obj) == 0) /* format error? */
lexerror(ls, "malformed number", TK_FLT);
if (ttisinteger(&obj)) {
seminfo->i = ivalue(&obj);
return TK_INT;
}
else {
lua_assert(ttisfloat(&obj));
seminfo->r = fltvalue(&obj);
return TK_FLT;
}
}
/*
** Try to convert a value to a float. The float case is already handled
** by the macro 'tonumber'.
*/
int luaV_tonumber_ (const TValue *obj, lua_Number *n) {
TValue v;
if (ttisinteger(obj)) {
*n = cast_num(ivalue(obj));
return 1;
}
else if (cvt2num(obj) && /* string convertible to number? */
luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) {
*n = nvalue(&v); /* convert result of 'luaO_str2num' to a float */
return 1;
}
else
return 0; /* conversion failed */
}
/*
** Try to convert a value to a float. Check 'isinteger' first, because
** in general the float case is already handled by the macro 'tonumber'.
*/
int luaV_tonumber_ (const TValue *obj, lua_Number *n) {
TValue v;
again:
if (ttisinteger(obj)) {
*n = cast_num(ivalue(obj));
return 1;
}
else if (ttisfloat(obj)) {
*n = fltvalue(obj);
return 1;
}
else if (cvt2num(obj) && /* string convertible to number? */
luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) {
obj = &v;
goto again; /* convert result from 'luaO_str2num' to a float */
}
return 0; /* conversion failed */
}
/*
** try to convert a value to an integer, rounding according to 'mode':
** mode == 0: accepts only integral values
** mode == 1: takes the floor of the number
** mode == 2: takes the ceil of the number
*/
int luaV_tointeger (const TValue *obj, lua_Integer *p, int mode) {
TValue v;
again:
if (ttisfloat(obj)) {
lua_Number n = fltvalue(obj);
lua_Number f = l_floor(n);
if (n != f) { /* not an integral value? */
if (mode == 0) return 0; /* fails if mode demands integral value */
else if (mode > 1) /* needs ceil? */
f += 1; /* convert floor to ceil (remember: n != f) */
}
return lua_numbertointeger(f, p);
}
else if (ttisinteger(obj)) {
*p = ivalue(obj);
return 1;
}
else if (cvt2num(obj) &&
luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) {
obj = &v;
goto again; /* convert result from 'luaO_str2num' to an integer */
}
return 0; /* conversion failed */
}
/*
** try to convert a value to an integer, rounding according to 'mode':
** mode == 0: accepts only integral values
** mode == 1: takes the floor of the number
** mode == 2: takes the ceil of the number
*/
int luaV_tointeger (const TValue *obj, lua_Integer *p, int mode) {
TValue v;
again:
#ifndef _KERNEL
if (ttisfloat(obj)) {
lua_Number n = fltvalue(obj);
lua_Number f = l_floor(n);
if (n != f) { /* not an integral value? */
if (mode == 0) return 0; /* fails if mode demands integral value */
else if (mode > 1) /* needs ceil? */
f += 1; /* convert floor to ceil (remember: n != f) */
}
return lua_numbertointeger(f, p);
}
else if (ttisinteger(obj)) {
#else /* _KERNEL */
if (ttisinteger(obj)) {
UNUSED(mode);
#endif
*p = ivalue(obj);
return 1;
}
else if (cvt2num(obj) &&
luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) {
obj = &v;
goto again; /* convert result from 'luaO_str2num' to an integer */
}
return 0; /* conversion failed */
}
#ifndef _KERNEL
/*
** Try to convert a 'for' limit to an integer, preserving the
** semantics of the loop.
** (The following explanation assumes a non-negative step; it is valid
** for negative steps mutatis mutandis.)
** If the limit can be converted to an integer, rounding down, that is
** it.
** Otherwise, check whether the limit can be converted to a number. If
** the number is too large, it is OK to set the limit as LUA_MAXINTEGER,
** which means no limit. If the number is too negative, the loop
** should not run, because any initial integer value is larger than the
** limit. So, it sets the limit to LUA_MININTEGER. 'stopnow' corrects
** the extreme case when the initial value is LUA_MININTEGER, in which
** case the LUA_MININTEGER limit would still run the loop once.
*/
static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step,
int *stopnow) {
*stopnow = 0; /* usually, let loops run */
if (!luaV_tointeger(obj, p, (step < 0 ? 2 : 1))) { /* not fit in integer? */
lua_Number n; /* try to convert to float */
if (!tonumber(obj, &n)) /* cannot convert to float? */
return 0; /* not a number */
if (luai_numlt(0, n)) { /* if true, float is larger than max integer */
*p = LUA_MAXINTEGER;
if (step < 0) *stopnow = 1;
}
else { /* float is smaller than min integer */
*p = LUA_MININTEGER;
if (step >= 0) *stopnow = 1;
}
}
return 1;
}
LUA_API size_t lua_stringtonumber (lua_State *L, const char *s) {
size_t sz = luaO_str2num(s, L->top);
if (sz != 0)
api_incr_top(L);
return sz;
}