public void Subtract(INumeric numeric)
{
if (numeric == null)
return;
//if (!this.HasCompatibleNumberSystem(numeric))
// throw new InvalidOperationException("incompatible number system");
var numeric1 = this.GetInnermostNumeric().Clone() as Numeric;
var numeric2 = numeric.GetInnermostNumeric().Clone() as Numeric;
numeric2.SwitchSign();
//apply whatever decorations this cake has to the clones
//we do this so that node hooks can be applied, for instance
var num2 = this.CloneDecorationCake(numeric2) as INumeric;
var num1 = this.CloneDecorationCake(numeric1) as INumeric;
var val = Add(num1, num2);
this.SetValue(val);
}
/// <summary>
///
/// </summary>
/// <param name="number1"></param>
/// <param name="number2"></param>
/// <param name="setValueIndicated">this is true if the return value is a clone and not the
/// same instance as number1</param>
/// <returns></returns>
private static INumeric Add(INumeric number1, INumeric number2)
{
if (number1 == null)
{
return number2;
}
if (number2 == null)
return number1;
// Debug.WriteLine("adding {0} {1}", number1.SymbolsText,
//number2.SymbolsText);
INumeric rv = null;
//determine the longer number
bool? num1IsLonger = Numeric.AbsoluteValueCompare(number1.GetInnermostNumeric(),
number2.GetInnermostNumeric());
//note: below we clone the 2nd arg if it is being modified as part of the operation
//we don't clone the 1st arg as it is
if (number1.IsPositive && number2.IsPositive)
{
rv = Increment(number1, number2);
}
else if (number1.IsPositive && number2.IsPositive == false)
{
switch (num1IsLonger)
{
case null:
rv = Decrement(number1, number2);
break;
case true:
rv = Decrement(number1, number2);
break;
case false:
rv = Decrement(number2, number1);
rv.GetInnermostNumeric().IsPositive = false;
break;
}
}
else if (number1.IsPositive == false && number2.IsPositive)
{
switch (num1IsLonger)
{
case null:
rv = Decrement(number1, number2);
break;
case true:
rv = Decrement(number1, number2);
break;
case false:
rv = Decrement(number2, number1);
rv.GetInnermostNumeric().IsPositive = true;
break;
}
}
else if (number1.IsPositive == false && number2.IsPositive == false)
{
rv = Increment(number1, number2);
rv.GetInnermostNumeric().IsPositive = false;
}
return rv;
}
public PrecisionNumericDecoration(object decorated,
INumeric decimalPlaces,
string cakeName = null)
: base(decorated, cakeName)
{
if (decimalPlaces == null)
throw new ArgumentNullException("decimalPlaces");
this.DecimalPlaces = decimalPlaces.GetInnermostNumeric();
}