ref: ebf235bfea04da1d12c77c84f9398c1c0d5aa0a8
dir: /jsnumber.c/
#include "jsi.h"
#include "jsvalue.h"
#include "jsbuiltin.h"
#if defined(_MSC_VER) && (_MSC_VER < 1700) /* VS2012 has stdint.h */
typedef unsigned __int64 uint64_t;
#else
#include <stdint.h>
#endif
static void jsB_new_Number(js_State *J)
{
js_newnumber(J, js_gettop(J) > 1 ? js_tonumber(J, 1) : 0);
}
static void jsB_Number(js_State *J)
{
js_pushnumber(J, js_gettop(J) > 1 ? js_tonumber(J, 1) : 0);
}
static void Np_valueOf(js_State *J)
{
js_Object *self = js_toobject(J, 0);
if (self->type != JS_CNUMBER) js_typeerror(J, "not a number");
js_pushnumber(J, self->u.number);
}
static void Np_toString(js_State *J)
{
char buf[100];
js_Object *self = js_toobject(J, 0);
int radix = js_isundefined(J, 1) ? 10 : js_tointeger(J, 1);
double x = 0;
if (self->type != JS_CNUMBER)
js_typeerror(J, "not a number");
x = self->u.number;
if (radix == 10) {
js_pushstring(J, jsV_numbertostring(J, buf, x));
return;
}
if (radix < 2 || radix > 36)
js_rangeerror(J, "invalid radix");
/* lame number to string conversion for any radix from 2 to 36 */
{
static const char digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
double number = x;
int sign = x < 0;
js_Buffer *sb = NULL;
uint64_t u, limit = ((uint64_t)1<<52);
int ndigits, exp, point;
if (number == 0) { js_pushstring(J, "0"); return; }
if (isnan(number)) { js_pushstring(J, "NaN"); return; }
if (isinf(number)) { js_pushstring(J, sign ? "-Infinity" : "Infinity"); return; }
if (sign)
number = -number;
/* fit as many digits as we want in an int */
exp = 0;
while (number * pow(radix, exp) > limit)
--exp;
while (number * pow(radix, exp+1) < limit)
++exp;
u = number * pow(radix, exp) + 0.5;
/* trim trailing zeros */
while (u > 0 && (u % radix) == 0) {
u /= radix;
--exp;
}
/* serialize digits */
ndigits = 0;
while (u > 0) {
buf[ndigits++] = digits[u % radix];
u /= radix;
}
point = ndigits - exp;
if (js_try(J)) {
js_free(J, sb);
js_throw(J);
}
if (sign)
js_putc(J, &sb, '-');
if (point <= 0) {
js_putc(J, &sb, '0');
js_putc(J, &sb, '.');
while (point++ < 0)
js_putc(J, &sb, '0');
while (ndigits-- > 0)
js_putc(J, &sb, buf[ndigits]);
} else {
while (ndigits-- > 0) {
js_putc(J, &sb, buf[ndigits]);
if (--point == 0 && ndigits > 0)
js_putc(J, &sb, '.');
}
while (point-- > 0)
js_putc(J, &sb, '0');
}
js_putc(J, &sb, 0);
js_pushstring(J, sb->s);
js_endtry(J);
js_free(J, sb);
}
}
/* Customized ToString() on a number */
static void numtostr(js_State *J, const char *fmt, int w, double n)
{
/* buf needs to fit printf("%.20f", 1e20) */
char buf[50], *e;
sprintf(buf, fmt, w, n);
e = strchr(buf, 'e');
if (e) {
int exp = atoi(e+1);
sprintf(e, "e%+d", exp);
}
js_pushstring(J, buf);
}
static void Np_toFixed(js_State *J)
{
js_Object *self = js_toobject(J, 0);
int width = js_tointeger(J, 1);
char buf[32];
double x;
if (self->type != JS_CNUMBER) js_typeerror(J, "not a number");
if (width < 0) js_rangeerror(J, "precision %d out of range", width);
if (width > 20) js_rangeerror(J, "precision %d out of range", width);
x = self->u.number;
if (isnan(x) || isinf(x) || x <= -1e21 || x >= 1e21)
js_pushstring(J, jsV_numbertostring(J, buf, x));
else
numtostr(J, "%.*f", width, x);
}
static void Np_toExponential(js_State *J)
{
js_Object *self = js_toobject(J, 0);
int width = js_tointeger(J, 1);
char buf[32];
double x;
if (self->type != JS_CNUMBER) js_typeerror(J, "not a number");
if (width < 0) js_rangeerror(J, "precision %d out of range", width);
if (width > 20) js_rangeerror(J, "precision %d out of range", width);
x = self->u.number;
if (isnan(x) || isinf(x))
js_pushstring(J, jsV_numbertostring(J, buf, x));
else
numtostr(J, "%.*e", width, x);
}
static void Np_toPrecision(js_State *J)
{
js_Object *self = js_toobject(J, 0);
int width = js_tointeger(J, 1);
char buf[32];
double x;
if (self->type != JS_CNUMBER) js_typeerror(J, "not a number");
if (width < 1) js_rangeerror(J, "precision %d out of range", width);
if (width > 21) js_rangeerror(J, "precision %d out of range", width);
x = self->u.number;
if (isnan(x) || isinf(x))
js_pushstring(J, jsV_numbertostring(J, buf, x));
else
numtostr(J, "%.*g", width, x);
}
void jsB_initnumber(js_State *J)
{
J->Number_prototype->u.number = 0;
js_pushobject(J, J->Number_prototype);
{
jsB_propf(J, "Number.prototype.valueOf", Np_valueOf, 0);
jsB_propf(J, "Number.prototype.toString", Np_toString, 1);
jsB_propf(J, "Number.prototype.toLocaleString", Np_toString, 0);
jsB_propf(J, "Number.prototype.toFixed", Np_toFixed, 1);
jsB_propf(J, "Number.prototype.toExponential", Np_toExponential, 1);
jsB_propf(J, "Number.prototype.toPrecision", Np_toPrecision, 1);
}
js_newcconstructor(J, jsB_Number, jsB_new_Number, "Number", 0); /* 1 */
{
jsB_propn(J, "MAX_VALUE", 1.7976931348623157e+308);
jsB_propn(J, "MIN_VALUE", 5e-324);
jsB_propn(J, "NaN", NAN);
jsB_propn(J, "NEGATIVE_INFINITY", -INFINITY);
jsB_propn(J, "POSITIVE_INFINITY", INFINITY);
}
js_defglobal(J, "Number", JS_DONTENUM);
}