// toFixed converts a number to a string, always formatting as an a decimal fraction.
// This method takes an argument specifying a number of decimal places to round the
// significand to. However when converting large values (1e+21 and above) this
// method will instead fallback to calling ToString.
EncodedJSValue JSC_HOST_CALL numberProtoFuncToFixed(ExecState* exec)
{
double x;
if (!toThisNumber(exec->thisValue(), x))
return throwVMTypeError(exec);
// Get the argument.
int decimalPlaces;
bool isUndefined; // This is ignored; undefined treated as 0.
if (!getIntegerArgumentInRange(exec, 0, 20, decimalPlaces, isUndefined))
return throwVMError(exec, createRangeError(exec, ASCIILiteral("toFixed() argument must be between 0 and 20")));
// 15.7.4.5.7 states "If x >= 10^21, then let m = ToString(x)"
// This also covers Ininity, and structure the check so that NaN
// values are also handled by numberToString
if (!(fabs(x) < 1e+21))
return JSValue::encode(jsString(exec, String::numberToStringECMAScript(x)));
// The check above will return false for NaN or Infinity, these will be
// handled by numberToString.
ASSERT(std::isfinite(x));
NumberToStringBuffer buffer;
return JSValue::encode(jsString(exec, String(numberToFixedWidthString(x, decimalPlaces, buffer))));
}
// toExponential converts a number to a string, always formatting as an expoential.
// This method takes an optional argument specifying a number of *decimal places*
// to round the significand to (or, put another way, this method optionally rounds
// to argument-plus-one significant figures).
EncodedJSValue JSC_HOST_CALL numberProtoFuncToExponential(ExecState* exec)
{
double x;
if (!toThisNumber(exec->thisValue(), x))
return throwVMTypeError(exec);
// Get the argument.
int decimalPlacesInExponent;
bool isUndefined;
if (!getIntegerArgumentInRange(exec, 0, 20, decimalPlacesInExponent, isUndefined))
return throwVMError(exec, createRangeError(exec, ASCIILiteral("toExponential() argument must be between 0 and 20")));
// Handle NaN and Infinity.
if (!std::isfinite(x))
return JSValue::encode(jsNontrivialString(exec, String::numberToStringECMAScript(x)));
// Round if the argument is not undefined, always format as exponential.
char buffer[WTF::NumberToStringBufferLength];
DoubleConversionStringBuilder builder(buffer, WTF::NumberToStringBufferLength);
const DoubleToStringConverter& converter = DoubleToStringConverter::EcmaScriptConverter();
builder.Reset();
isUndefined
? converter.ToExponential(x, -1, &builder)
: converter.ToExponential(x, decimalPlacesInExponent, &builder);
return JSValue::encode(jsString(exec, String(builder.Finalize())));
}
// toPrecision converts a number to a string, takeing an argument specifying a
// number of significant figures to round the significand to. For positive
// exponent, all values that can be represented using a decimal fraction will
// be, e.g. when rounding to 3 s.f. any value up to 999 will be formated as a
// decimal, whilst 1000 is converted to the exponential representation 1.00e+3.
// For negative exponents values >= 1e-6 are formated as decimal fractions,
// with smaller values converted to exponential representation.
EncodedTiValue JSC_HOST_CALL numberProtoFuncToPrecision(TiExcState* exec)
{
// Get x (the double value of this, which should be a Number).
TiValue thisValue = exec->hostThisValue();
TiValue v = thisValue.getJSNumber();
if (!v)
return throwVMTypeError(exec);
double x = v.uncheckedGetNumber();
// Get the argument.
int significantFigures;
bool isUndefined;
if (!getIntegerArgumentInRange(exec, 1, 21, significantFigures, isUndefined))
return throwVMError(exec, createRangeError(exec, "toPrecision() argument must be between 1 and 21"));
// To precision called with no argument is treated as ToString.
if (isUndefined)
return TiValue::encode(jsString(exec, UString::number(x)));
// Handle NaN and Infinity.
if (isnan(x) || isinf(x))
return TiValue::encode(jsString(exec, UString::number(x)));
// Convert to decimal with rounding.
DecimalNumber number(x, RoundingSignificantFigures, significantFigures);
// If number is in the range 1e-6 <= x < pow(10, significantFigures) then format
// as decimal. Otherwise, format the number as an exponential. Decimal format
// demands a minimum of (exponent + 1) digits to represent a number, for example
// 1234 (1.234e+3) requires 4 digits. (See ECMA-262 15.7.4.7.10.c)
NumberToStringBuffer buffer;
unsigned length = number.exponent() >= -6 && number.exponent() < significantFigures
? number.toStringDecimal(buffer, WTI::NumberToStringBufferLength)
: number.toStringExponential(buffer, WTI::NumberToStringBufferLength);
return TiValue::encode(jsString(exec, UString(buffer, length)));
}
// toFixed converts a number to a string, always formatting as an a decimal fraction.
// This method takes an argument specifying a number of decimal places to round the
// significand to. However when converting large values (1e+21 and above) this
// method will instead fallback to calling ToString.
EncodedTiValue JSC_HOST_CALL numberProtoFuncToFixed(TiExcState* exec)
{
// Get x (the double value of this, which should be a Number).
TiValue thisValue = exec->hostThisValue();
TiValue v = thisValue.getJSNumber();
if (!v)
return throwVMTypeError(exec);
double x = v.uncheckedGetNumber();
// Get the argument.
int decimalPlaces;
bool isUndefined; // This is ignored; undefined treated as 0.
if (!getIntegerArgumentInRange(exec, 0, 20, decimalPlaces, isUndefined))
return throwVMError(exec, createRangeError(exec, "toFixed() argument must be between 0 and 20"));
// 15.7.4.5.7 states "If x >= 10^21, then let m = ToString(x)"
// This also covers Ininity, and structure the check so that NaN
// values are also handled by numberToString
if (!(fabs(x) < 1e+21))
return TiValue::encode(jsString(exec, UString::number(x)));
// The check above will return false for NaN or Infinity, these will be
// handled by numberToString.
ASSERT(!isnan(x) && !isinf(x));
// Convert to decimal with rounding, and format as decimal.
NumberToStringBuffer buffer;
unsigned length = DecimalNumber(x, RoundingDecimalPlaces, decimalPlaces).toStringDecimal(buffer, WTI::NumberToStringBufferLength);
return TiValue::encode(jsString(exec, UString(buffer, length)));
}
// toExponential converts a number to a string, always formatting as an expoential.
// This method takes an optional argument specifying a number of *decimal places*
// to round the significand to (or, put another way, this method optionally rounds
// to argument-plus-one significant figures).
EncodedTiValue JSC_HOST_CALL numberProtoFuncToExponential(TiExcState* exec)
{
// Get x (the double value of this, which should be a Number).
double x;
if (!toThisNumber(exec->hostThisValue(), x))
return throwVMTypeError(exec);
// Get the argument.
int decimalPlacesInExponent;
bool isUndefined;
if (!getIntegerArgumentInRange(exec, 0, 20, decimalPlacesInExponent, isUndefined))
return throwVMError(exec, createRangeError(exec, "toExponential() argument must be between 0 and 20"));
// Handle NaN and Infinity.
if (isnan(x) || isinf(x))
return TiValue::encode(jsString(exec, UString::number(x)));
// Round if the argument is not undefined, always format as exponential.
NumberToStringBuffer buffer;
unsigned length = isUndefined
? DecimalNumber(x).toStringExponential(buffer, WTI::NumberToStringBufferLength)
: DecimalNumber(x, RoundingSignificantFigures, decimalPlacesInExponent + 1).toStringExponential(buffer, WTI::NumberToStringBufferLength);
return TiValue::encode(jsString(exec, UString(buffer, length)));
}
// toPrecision converts a number to a string, takeing an argument specifying a
// number of significant figures to round the significand to. For positive
// exponent, all values that can be represented using a decimal fraction will
// be, e.g. when rounding to 3 s.f. any value up to 999 will be formated as a
// decimal, whilst 1000 is converted to the exponential representation 1.00e+3.
// For negative exponents values >= 1e-6 are formated as decimal fractions,
// with smaller values converted to exponential representation.
EncodedJSValue JSC_HOST_CALL numberProtoFuncToPrecision(ExecState* exec)
{
double x;
if (!toThisNumber(exec->thisValue(), x))
return throwVMTypeError(exec);
// Get the argument.
int significantFigures;
bool isUndefined;
if (!getIntegerArgumentInRange(exec, 1, 21, significantFigures, isUndefined))
return throwVMError(exec, createRangeError(exec, ASCIILiteral("toPrecision() argument must be between 1 and 21")));
// To precision called with no argument is treated as ToString.
if (isUndefined)
return JSValue::encode(jsString(exec, String::numberToStringECMAScript(x)));
// Handle NaN and Infinity.
if (!std::isfinite(x))
return JSValue::encode(jsNontrivialString(exec, String::numberToStringECMAScript(x)));
NumberToStringBuffer buffer;
return JSValue::encode(jsString(exec, String(numberToFixedPrecisionString(x, significantFigures, buffer))));
}
