bool UString::getCString(CStringBuffer& buffer) const
{
int length = size();
int neededSize = length + 1;
buffer.resize(neededSize);
char* buf = buffer.data();
UChar ored = 0;
const UChar* p = data();
char* q = buf;
const UChar* limit = p + length;
while (p != limit) {
UChar c = p[0];
ored |= c;
*q = static_cast<char>(c);
++p;
++q;
}
*q = '\0';
return !(ored & 0xFF00);
}
double UString::toDouble(bool tolerateTrailingJunk, bool tolerateEmptyString) const
{
double d;
// FIXME: If tolerateTrailingJunk is true, then we want to tolerate non-8-bit junk
// after the number, so this is too strict a check.
CStringBuffer s;
if (!getCString(s))
return NaN;
const char* c = s.data();
// skip leading white space
while (isASCIISpace(*c))
c++;
// empty string ?
if (*c == '\0')
return tolerateEmptyString ? 0.0 : NaN;
// hex number ?
if (*c == '0' && (*(c + 1) == 'x' || *(c + 1) == 'X')) {
const char* firstDigitPosition = c + 2;
c++;
d = 0.0;
while (*(++c)) {
if (*c >= '0' && *c <= '9')
d = d * 16.0 + *c - '0';
else if ((*c >= 'A' && *c <= 'F') || (*c >= 'a' && *c <= 'f'))
d = d * 16.0 + (*c & 0xdf) - 'A' + 10.0;
else
break;
}
if (d >= mantissaOverflowLowerBound)
d = parseIntOverflow(firstDigitPosition, c - firstDigitPosition, 16);
} else {
// regular number ?
char* end;
d = strtod(c, &end);
if ((d != 0.0 || end != c) && d != Inf && d != -Inf) {
c = end;
} else {
double sign = 1.0;
if (*c == '+')
c++;
else if (*c == '-') {
sign = -1.0;
c++;
}
// We used strtod() to do the conversion. However, strtod() handles
// infinite values slightly differently than JavaScript in that it
// converts the string "inf" with any capitalization to infinity,
// whereas the ECMA spec requires that it be converted to NaN.
if (c[0] == 'I' && c[1] == 'n' && c[2] == 'f' && c[3] == 'i' && c[4] == 'n' && c[5] == 'i' && c[6] == 't' && c[7] == 'y') {
d = sign * Inf;
c += 8;
} else if ((d == Inf || d == -Inf) && *c != 'I' && *c != 'i')
c = end;
else
return NaN;
}
}
// allow trailing white space
while (isASCIISpace(*c))
c++;
// don't allow anything after - unless tolerant=true
if (!tolerateTrailingJunk && *c != '\0')
d = NaN;
return d;
}