jsnum.c

java script test programing source code

}

JSBool
js_ValueToECMAInt32(JSContext *cx, jsval v, int32 *ip)
{
    jsdouble d;

    if (!js_ValueToNumber(cx, v, &d))
        return JS_FALSE;
    return js_DoubleToECMAInt32(cx, d, ip);
}

JSBool
js_DoubleToECMAInt32(JSContext *cx, jsdouble d, int32 *ip)
{
    jsdouble two32 = 4294967296.0;
    jsdouble two31 = 2147483648.0;

    if (!JSDOUBLE_IS_FINITE(d) || d == 0) {
        *ip = 0;
        return JS_TRUE;
    }
    d = fmod(d, two32);
    d = (d >= 0) ? floor(d) : ceil(d) + two32;
    if (d >= two31)
        *ip = (int32)(d - two32);
    else
        *ip = (int32)d;
    return JS_TRUE;
}

JSBool
js_ValueToECMAUint32(JSContext *cx, jsval v, uint32 *ip)
{
    jsdouble d;

    if (!js_ValueToNumber(cx, v, &d))
        return JS_FALSE;
    return js_DoubleToECMAUint32(cx, d, ip);
}

JSBool
js_DoubleToECMAUint32(JSContext *cx, jsdouble d, uint32 *ip)
{
    JSBool neg;
    jsdouble two32 = 4294967296.0;

    if (!JSDOUBLE_IS_FINITE(d) || d == 0) {
        *ip = 0;
        return JS_TRUE;
    }

    neg = (d < 0);
    d = floor(neg ? -d : d);
    d = neg ? -d : d;

    d = fmod(d, two32);

    d = (d >= 0) ? d : d + two32;
    *ip = (uint32)d;
    return JS_TRUE;
}

JSBool
js_ValueToInt32(JSContext *cx, jsval v, int32 *ip)
{
    jsdouble d;
    JSString *str;

    if (JSVAL_IS_INT(v)) {
        *ip = JSVAL_TO_INT(v);
        return JS_TRUE;
    }
    if (!js_ValueToNumber(cx, v, &d))
        return JS_FALSE;
    if (JSDOUBLE_IS_NaN(d) || d <= -2147483649.0 || 2147483648.0 <= d) {
        str = js_DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, v, NULL);
        if (str) {
            JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                                 JSMSG_CANT_CONVERT, JS_GetStringBytes(str));

        }
        return JS_FALSE;
    }
    *ip = (int32)floor(d + 0.5);     /* Round to nearest */
    return JS_TRUE;
}

JSBool
js_ValueToUint16(JSContext *cx, jsval v, uint16 *ip)
{
    jsdouble d;
    jsuint i, m;
    JSBool neg;

    if (!js_ValueToNumber(cx, v, &d))
        return JS_FALSE;
    if (d == 0 || !JSDOUBLE_IS_FINITE(d)) {
        *ip = 0;
        return JS_TRUE;
    }
    i = (jsuint)d;
    if ((jsdouble)i == d) {
        *ip = (uint16)i;
        return JS_TRUE;
    }
    neg = (d < 0);
    d = floor(neg ? -d : d);
    d = neg ? -d : d;
    m = JS_BIT(16);
    d = fmod(d, (double)m);
    if (d < 0)
        d += m;
    *ip = (uint16) d;
    return JS_TRUE;
}

jsdouble
js_DoubleToInteger(jsdouble d)
{
    JSBool neg;

    if (d == 0)
        return d;
    if (!JSDOUBLE_IS_FINITE(d)) {
        if (JSDOUBLE_IS_NaN(d))
            return 0;
        return d;
    }
    neg = (d < 0);
    d = floor(neg ? -d : d);
    return neg ? -d : d;
}


JSBool
js_strtod(JSContext *cx, const jschar *s, const jschar **ep, jsdouble *dp)
{
    char cbuf[32];
    size_t i;
    char *cstr, *istr, *estr;
    JSBool negative;
    jsdouble d;
    const jschar *s1 = js_SkipWhiteSpace(s);
    size_t length = js_strlen(s1);

    /* Use cbuf to avoid malloc */
    if (length >= sizeof cbuf) {
        cstr = (char *) JS_malloc(cx, length + 1);
        if (!cstr)
           return JS_FALSE;
    } else {
        cstr = cbuf;
    }

    for (i = 0; i <= length; i++) {
        if (s1[i] >> 8) {
            cstr[i] = 0;
            break;
        }
        cstr[i] = (char)s1[i];
    }

    istr = cstr;
    if ((negative = (*istr == '-')) != 0 || *istr == '+')
        istr++;
    if (!strncmp(istr, js_Infinity_str, sizeof js_Infinity_str - 1)) {
        d = *(negative ? cx->runtime->jsNegativeInfinity : cx->runtime->jsPositiveInfinity);
        estr = istr + 8;
    } else {
        int err;
        d = JS_strtod(cstr, &estr, &err);
        if (err == JS_DTOA_ENOMEM) {
            JS_ReportOutOfMemory(cx);
            if (cstr != cbuf)
                JS_free(cx, cstr);
            return JS_FALSE;
        }
        if (err == JS_DTOA_ERANGE) {
            if (d == HUGE_VAL)
                d = *cx->runtime->jsPositiveInfinity;
            else if (d == -HUGE_VAL)
                d = *cx->runtime->jsNegativeInfinity;
        }
#ifdef HPUX
        if (d == 0.0 && negative) {
            /*
             * "-0", "-1e-2000" come out as positive zero
             * here on HPUX. Force a negative zero instead.
             */
            JSDOUBLE_HI32(d) = JSDOUBLE_HI32_SIGNBIT;
            JSDOUBLE_LO32(d) = 0;
        }
#endif
    }

    i = estr - cstr;
    if (cstr != cbuf)
        JS_free(cx, cstr);
    *ep = i ? s1 + i : s;
    *dp = d;
    return JS_TRUE;
}

struct BinaryDigitReader
{
    uintN base;                 /* Base of number; must be a power of 2 */
    uintN digit;                /* Current digit value in radix given by base */
    uintN digitMask;            /* Mask to extract the next bit from digit */
    const jschar *digits;       /* Pointer to the remaining digits */
    const jschar *end;          /* Pointer to first non-digit */
};

/* Return the next binary digit from the number or -1 if done */
static intN GetNextBinaryDigit(struct BinaryDigitReader *bdr)
{
    intN bit;

    if (bdr->digitMask == 0) {
        uintN c;

        if (bdr->digits == bdr->end)
            return -1;

        c = *bdr->digits++;
        if ('0' <= c && c <= '9')
            bdr->digit = c - '0';
        else if ('a' <= c && c <= 'z')
            bdr->digit = c - 'a' + 10;
        else bdr->digit = c - 'A' + 10;
        bdr->digitMask = bdr->base >> 1;
    }
    bit = (bdr->digit & bdr->digitMask) != 0;
    bdr->digitMask >>= 1;
    return bit;
}

JSBool
js_strtointeger(JSContext *cx, const jschar *s, const jschar **ep, jsint base, jsdouble *dp)
{
    JSBool negative;
    jsdouble value;
    const jschar *start;
    const jschar *s1 = js_SkipWhiteSpace(s);

    if ((negative = (*s1 == '-')) != 0 || *s1 == '+')
        s1++;

    if (base == 0) {
        /* No base supplied, or some base that evaluated to 0. */
        if (*s1 == '0') {
            /* It's either hex or octal; only increment char if str isn't '0' */
            if (s1[1] == 'X' || s1[1] == 'x') { /* Hex */
                s1 += 2;
                base = 16;
            } else {    /* Octal */
                base = 8;
            }
        } else {
            base = 10; /* Default to decimal. */
        }
    } else if (base == 16 && *s1 == '0' && (s1[1] == 'X' || s1[1] == 'x')) {
        /* If base is 16, ignore hex prefix. */
        s1 += 2;
    }

    /*
     * Done with the preliminaries; find some prefix of the string that's
     * a number in the given base.
     */
    start = s1; /* Mark - if string is empty, we return NaN. */
    value = 0.0;
    for (;;) {
        uintN digit;
        jschar c = *s1;
        if ('0' <= c && c <= '9')
            digit = c - '0';
        else if ('a' <= c && c <= 'z')
            digit = c - 'a' + 10;
        else if ('A' <= c && c <= 'Z')
            digit = c - 'A' + 10;
        else
            break;
        if (digit >= (uintN)base)
            break;
        value = value * base + digit;
        s1++;
    }

    if (value >= 9007199254740992.0) {
        if (base == 10) {
            /*
             * If we're accumulating a decimal number and the number is >=
             * 2^53, then the result from the repeated multiply-add above may
             * be inaccurate.  Call JS_strtod to get the correct answer.
             */
            size_t i;
            size_t length = s1 - start;
            char *cstr = (char *) JS_malloc(cx, length + 1);
            char *estr;
            int err=0;

            if (!cstr)
                return JS_FALSE;
            for (i = 0; i != length; i++)
                cstr[i] = (char)start[i];
            cstr[length] = 0;

            value = JS_strtod(cstr, &estr, &err);
            if (err == JS_DTOA_ENOMEM) {
                JS_ReportOutOfMemory(cx);
                JS_free(cx, cstr);
                return JS_FALSE;
            }
            if (err == JS_DTOA_ERANGE && value == HUGE_VAL)
                value = *cx->runtime->jsPositiveInfinity;
            JS_free(cx, cstr);
        } else if ((base & (base - 1)) == 0) {
            /*
             * The number may also be inaccurate for power-of-two bases.  This
             * happens if the addition in value * base + digit causes a round-
             * down to an even least significant mantissa bit when the first
             * dropped bit is a one.  If any of the following digits in the
             * number (which haven't been added in yet) are nonzero, then the
             * correct action would have been to round up instead of down.  An
             * example occurs when reading the number 0x1000000000000081, which
             * rounds to 0x1000000000000000 instead of 0x1000000000000100.
             */
            struct BinaryDigitReader bdr;
            intN bit, bit2;
            intN j;

            bdr.base = base;
            bdr.digitMask = 0;
            bdr.digits = start;
            bdr.end = s1;
            value = 0.0;

            /* Skip leading zeros. */
            do {
                bit = GetNextBinaryDigit(&bdr);
            } while (bit == 0);

            if (bit == 1) {
                /* Gather the 53 significant bits (including the leading 1) */
                value = 1.0;
                for (j = 52; j; j--) {
                    bit = GetNextBinaryDigit(&bdr);
                    if (bit < 0)
                        goto done;
                    value = value*2 + bit;
                }
                /* bit2 is the 54th bit (the first dropped from the mantissa) */
                bit2 = GetNextBinaryDigit(&bdr);
                if (bit2 >= 0) {
                    jsdouble factor = 2.0;
                    intN sticky = 0;  /* sticky is 1 if any bit beyond the 54th is 1 */
                    intN bit3;

                    while ((bit3 = GetNextBinaryDigit(&bdr)) >= 0) {
                        sticky |= bit3;
                        factor *= 2;
                    }
                    value += bit2 & (bit | sticky);
                    value *= factor;
                }
              done:;
            }
        }
    }
    /* We don't worry about inaccurate numbers for any other base. */

    if (s1 == start) {
        *dp = 0.0;
        *ep = s;
    } else {
        *dp = negative ? -value : value;
        *ep = s1;
    }
    return JS_TRUE;
}