Permil.cs

using System;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Operators.Arithmetics
{
    public class Permil : UnaryDoubleOperator, IDifferentiable
    {
        public Permil(ScriptNode Operand, int Start, int Length, Expression Expression)
            : base(Operand, Start, Length, Expression)
        {
        }
    
        public override IElement Evaluate(double Operand)
        {
            return new DoubleNumber(Operand / 1000);
        }
 
        public ScriptNode Differentiate(string VariableName, Variables Variables)
        {
            if (this.op is IDifferentiable Differentiable)
            {
                return new Permil(
                    Differentiable.Differentiate(VariableName, Variables),
                    this.Start, this.Length, this.Expression);
            }
            else
                throw new ScriptRuntimeException("Operand not differentiable.", this);
        }
    }
}