private static bool TryParse(string s, out MathContext context, out Exception exception)
{
char[] charVal = s.ToCharArray();
int i; // Index of charVal
int j; // Index of chRoundingMode
int digit; // It will contain the digit parsed
if ((charVal.Length < 27) || (charVal.Length > 45))
{
// math.0E=bad string format
exception = new FormatException(Messages.math0E); //$NON-NLS-1$
context = null;
return(false);
}
// Parsing "precision=" String
for (i = 0; (i < chPrecision.Length) && (charVal[i] == chPrecision[i]); i++)
{
}
if (i < chPrecision.Length)
{
// math.0E=bad string format
throw new FormatException(Messages.math0E); //$NON-NLS-1$
}
// Parsing the value for "precision="...
digit = CharHelper.toDigit(charVal[i], 10);
if (digit == -1)
{
// math.0E=bad string format
exception = new FormatException(Messages.math0E); //$NON-NLS-1$
context = null;
return(false);
}
var precision = digit;
i++;
do
{
digit = CharHelper.toDigit(charVal[i], 10);
if (digit == -1)
{
if (charVal[i] == ' ')
{
// It parsed all the digits
i++;
break;
}
// It isn't a valid digit, and isn't a white space
// math.0E=bad string format
exception = new ArgumentException(Messages.math0E); //$NON-NLS-1$
context = null;
return(false);
}
// Accumulating the value parsed
precision = precision * 10 + digit;
if (precision < 0)
{
// math.0E=bad string format
exception = new ArgumentException(Messages.math0E); //$NON-NLS-1$
context = null;
return(false);
}
i++;
} while (true);
// Parsing "roundingMode="
for (j = 0; (j < chRoundingMode.Length) &&
(charVal[i] == chRoundingMode[j]); i++, j++)
{
;
}
if (j < chRoundingMode.Length)
{
// math.0E=bad string format
throw new FormatException(Messages.math0E); //$NON-NLS-1$
}
RoundingMode roundingMode;
try {
// Parsing the value for "roundingMode"...
roundingMode = (RoundingMode)Enum.Parse(typeof(RoundingMode), new string(charVal, i, charVal.Length - i), true);
} catch (Exception ex) {
exception = ex;
context = null;
return(false);
}
exception = null;
context = new MathContext(precision, roundingMode);
return(true);
}
/**
* Constructs a new {@code MathContext} from a string. The string has to
* specify the precision and the rounding mode to be used and has to follow
* the following syntax: "precision=<precision> roundingMode=<roundingMode>"
* This is the same form as the one returned by the {@link #ToString}
* method.
*
* @param val
* a string describing the precision and rounding mode for the
* new {@code MathContext}.
* @throws IllegalArgumentException
* if the string is not in the correct format or if the
* precision specified is < 0.
*/
public MathContext(String val)
{
char[] charVal = val.ToCharArray();
int i; // Index of charVal
int j; // Index of chRoundingMode
int digit; // It will contain the digit parsed
if ((charVal.Length < 27) || (charVal.Length > 45))
{
// math.0E=bad string format
throw new ArgumentException(Messages.math0E); //$NON-NLS-1$
}
// Parsing "precision=" String
for (i = 0; (i < chPrecision.Length) && (charVal[i] == chPrecision[i]); i++)
{
;
}
if (i < chPrecision.Length)
{
// math.0E=bad string format
throw new ArgumentException(Messages.math0E); //$NON-NLS-1$
}
// Parsing the value for "precision="...
digit = CharHelper.toDigit(charVal[i], 10);
if (digit == -1)
{
// math.0E=bad string format
throw new ArgumentException(Messages.math0E); //$NON-NLS-1$
}
this.precision = this.precision * 10 + digit;
i++;
do
{
digit = CharHelper.toDigit(charVal[i], 10);
if (digit == -1)
{
if (charVal[i] == ' ')
{
// It parsed all the digits
i++;
break;
}
// It isn't a valid digit, and isn't a white space
// math.0E=bad string format
throw new ArgumentException(Messages.math0E); //$NON-NLS-1$
}
// Accumulating the value parsed
this.precision = this.precision * 10 + digit;
if (this.precision < 0)
{
// math.0E=bad string format
throw new ArgumentException(Messages.math0E); //$NON-NLS-1$
}
i++;
} while (true);
// Parsing "roundingMode="
for (j = 0; (j < chRoundingMode.Length) &&
(charVal[i] == chRoundingMode[j]); i++, j++)
{
;
}
if (j < chRoundingMode.Length)
{
// math.0E=bad string format
throw new ArgumentException(Messages.math0E); //$NON-NLS-1$
}
// Parsing the value for "roundingMode"...
this.roundingMode = (RoundingMode)Enum.Parse(typeof(RoundingMode), new string(charVal, i, charVal.Length - i), true);
}
