/// <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 DR = Right as DoubleNumber;
if (Left is DoubleNumber DL && DR != null)
{
return(new DoubleNumber(Math.Pow(DL.Value, DR.Value)));
}
if (Left is IRingElement LE && 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)
{
if (!(LE is ICommutativeRingWithIdentityElement LE2))
{
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));
}
}
}
}
/// <summary>
/// Divides the left operand from the right one.
/// </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 EvaluateDivision(IElement Left, IElement Right, ScriptNode Node)
{
IElement Result;
IRingElement Temp;
if (Left is IRingElement LE && !(!(Right is IRingElement RE)))
{
// TODO: Optimize in case of matrices. It's more efficient to employ a solve algorithm than to compute the inverse and the multiply.
Temp = LE.Invert();
if (!(Temp is null))
{
Result = RE.MultiplyLeft(Temp);
if (!(Result is null))
{
return(Result);
}
Result = Temp.MultiplyRight(RE);
if (!(Result is null))
{
return(Result);
}
}
}
if (Left.IsScalar)
{
if (Right.IsScalar)
{
ISet LeftSet = Left.AssociatedSet;
ISet RightSet = Right.AssociatedSet;
if (!LeftSet.Equals(RightSet))
{
if (!Expression.UpgradeField(ref Left, ref LeftSet, ref Right, ref RightSet, Node))
{
throw new ScriptRuntimeException("Incompatible operands.", Node);
}
LE = Left as IRingElement;
RE = Right as IRingElement;
if (!(LE is null) && !(RE is null))
{
Temp = LE.Invert();
if (!(Temp is null))
{
Result = RE.MultiplyLeft(Temp);
if (!(Result is null))
{
return(Result);
}
Result = Temp.MultiplyRight(RE);
if (!(Result is null))
{
return(Result);
}
}
}
}
throw new ScriptRuntimeException("Operands cannot be divided.", Node);
}
else
{
LinkedList <IElement> Elements = new LinkedList <IElement>();
foreach (IElement RightChild in Right.ChildElements)
{
Elements.AddLast(EvaluateDivision(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(EvaluateDivision(LeftChild, Right, Node));
}
return(Left.Encapsulate(Elements, Node));
}
else
{
if (Left is ISet Set1 && !(!(Right is ISet Set2)))
{
return(new SetDifference(Set1, Set2));
}