Square.cs

using Waher.Runtime.Collections;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Operators.Arithmetics
{
    public class Square : UnaryOperator, IDifferentiable
    {
        public Square(ScriptNode Operand, int Start, int Length, Expression Expression)
            : base(Operand, Start, Length, Expression)
        {
        }
 
        public override IElement Evaluate(IElement Operand, Variables Variables)
        {
            if (Operand.AssociatedObjectValue is double d)
                return new DoubleNumber(d * d);
 
            if (Operand is IRingElement E)
                return Multiply.EvaluateMultiplication(E, E, this);
 
            if (Operand.IsScalar)
                throw new ScriptRuntimeException("Scalar operands must be double values or ring elements.", this);
 
            ChunkedList<IElement> Result = new ChunkedList<IElement>();
 
            foreach (IElement Child in Operand.ChildElements)
                Result.Add(this.Evaluate(Child, Variables));
 
            return Operand.Encapsulate(Result, this);
        }
 
        public ScriptNode Differentiate(string VariableName, Variables Variables)
        {
            int Start = this.Start;
            int Len = this.Length;
            Expression Expression = this.Expression;
 
            return this.DifferentiationChainRule(VariableName, Variables, this.op,
                new Multiply(
                    new ConstantElement(DoubleNumber.TwoElement, Start, Len, Expression),
                    this.op,
                    Start, Len, Expression));
        }
 
    }
}