/** Rounds this Numeric to the given precision, and rounds a half to even */
Numeric::Ptr ATDecimalOrDerivedImpl::roundHalfToEven(const Numeric::Ptr &precision, const DynamicContext* context) const {
ATDecimalOrDerived::Ptr decimal_precision = (const Numeric::Ptr)precision->castAs(this->getPrimitiveTypeIndex(), context);
MAPM exp = MAPM(10).pow(((ATDecimalOrDerivedImpl*)(const ATDecimalOrDerived*)decimal_precision)->_decimal);
MAPM value = _decimal * exp;
bool halfVal = false;
// check if we're rounding on a half value
if((value-0.5) == (value.floor())) {
halfVal = true;
}
value = _decimal * exp + 0.5;
value = value.floor();
// if halfVal make sure what we return has the least significant digit even
if (halfVal) {
if(value.is_odd()) {
value = value - 1;
}
}
value = value / exp;
// if integer, return xs:integer, otherwise xs:decimal
if(_isInteger) {
return context->getItemFactory()->createInteger(value, context);
}
return context->getItemFactory()->createDecimal(value, context);
}
/** Rounds this Numeric to the given precision, and rounds a half to even */
Numeric::Ptr ATFloatOrDerivedImpl::roundHalfToEven(const Numeric::Ptr &precision, const DynamicContext* context) const {
switch (_state) {
case NaN:
return notANumber(context);
case INF:
return infinity(context);
case NEG_INF:
return negInfinity(context);
case NEG_NUM:
case NUM:
break;
default: {
assert(false);
return 0; // should never get here
}
}
if (isZero() && isNegative())
return this;
ATFloatOrDerived::Ptr float_precision = (const Numeric::Ptr)precision->castAs(this->getPrimitiveTypeIndex(), context);
MAPM exp = MAPM(10).pow(((ATFloatOrDerivedImpl*)(const ATFloatOrDerived*)float_precision)->_float);
MAPM value = _float * exp;
bool halfVal = false;
// check if we're rounding on a half value
if((value-0.5) == (value.floor())) {
halfVal = true;
}
value = _float * exp + 0.5;
value = value.floor();
// if halfVal make sure what we return has the least significant digit even
if (halfVal) {
if(value.is_odd()) {
value = value - 1;
}
}
value = value / exp;
// the spec doesn't actually say to do this, but djf believes this is the correct way to handle rounding of -ve values which will result in 0.0E0
// if (value == 0 && isNegative())
// return negZero(context);
return newFloat(value, context);
}
