/// <summary>
/// Calculates Left ^ Right.
/// </summary>
/// <param name="Left">Left operand.</param>
/// <param name="Right">Right operand.</param>
/// <param name="Node">Node performing the operation.</param>
/// <returns>Result</returns>
public static IElement EvaluatePower(IElement Left, IElement Right, ScriptNode Node)
{
DoubleNumber DL = Left as DoubleNumber;
DoubleNumber DR = Right as DoubleNumber;
if (DL != null && DR != null)
{
return(new DoubleNumber(Math.Pow(DL.Value, DR.Value)));
}
IRingElement LE = Left as IRingElement;
if (LE != null && DR != null)
{
double d = DR.Value;
if (d >= long.MinValue && d <= long.MaxValue && Math.Truncate(d) == d)
{
long n = (long)d;
if (n < 0)
{
LE = LE.Invert();
if (LE == null)
{
throw new ScriptRuntimeException("Base element not invertible.", Node);
}
n = -n;
}
else if (n == 0)
{
ICommutativeRingWithIdentityElement LE2 = LE as ICommutativeRingWithIdentityElement;
if (LE2 == null)
{
throw new ScriptRuntimeException("Base element ring does not have unity.", Node);
}
return(LE2.One);
}
IRingElement Result = null;
while (n > 0)
{
if ((n & 1) == 1)
{
if (Result == null)
{
Result = LE;
}
else
{
Result = (IRingElement)Multiply.EvaluateMultiplication(Result, LE, Node);
}
}
n >>= 1;
if (n > 0)
{
LE = (IRingElement)Multiply.EvaluateMultiplication(LE, LE, Node);
}
}
return(Result);
}
else
{
throw new ScriptRuntimeException("Exponent too large.", Node);
}
}
if (Left.IsScalar)
{
if (Right.IsScalar)
{
throw new ScriptRuntimeException("Power operation could not be computed.", Node);
}
else
{
LinkedList <IElement> Elements = new LinkedList <IElement>();
foreach (IElement RightChild in Right.ChildElements)
{
Elements.AddLast(EvaluatePower(Left, RightChild, Node));
}
return(Right.Encapsulate(Elements, Node));
}
}
else
{
if (Right.IsScalar)
{
LinkedList <IElement> Elements = new LinkedList <IElement>();
foreach (IElement LeftChild in Left.ChildElements)
{
Elements.AddLast(EvaluatePower(LeftChild, Right, Node));
}
return(Left.Encapsulate(Elements, Node));
}
else
{
ICollection <IElement> LeftChildren = Left.ChildElements;
ICollection <IElement> RightChildren = Right.ChildElements;
if (LeftChildren.Count == RightChildren.Count)
{
LinkedList <IElement> Elements = new LinkedList <IElement>();
IEnumerator <IElement> eLeft = LeftChildren.GetEnumerator();
IEnumerator <IElement> eRight = RightChildren.GetEnumerator();
try
{
while (eLeft.MoveNext() && eRight.MoveNext())
{
Elements.AddLast(EvaluatePower(eLeft.Current, eRight.Current, Node));
}
}
finally
{
eLeft.Dispose();
eRight.Dispose();
}
return(Left.Encapsulate(Elements, Node));
}
else
{
LinkedList <IElement> LeftResult = new LinkedList <IElement>();
foreach (IElement LeftChild in LeftChildren)
{
LinkedList <IElement> RightResult = new LinkedList <IElement>();
foreach (IElement RightChild in RightChildren)
{
RightResult.AddLast(EvaluatePower(LeftChild, RightChild, Node));
}
LeftResult.AddLast(Right.Encapsulate(RightResult, Node));
}
return(Left.Encapsulate(LeftResult, Node));
}
}
}
}