ProductEvaluator.cs

using Waher.Script.Abstraction.Elements;
using Waher.Script.Model;
using Waher.Script.Objects;
using Waher.Script.Operators.Arithmetics;
 
namespace Waher.Script.Functions.Vectors
{
    public class ProductEvaluator : UnaryIterativeEvaluator
    {
        private IElement product = null;
        private double doubleProduct = 0;
        private bool isDouble = true;
 
        public ProductEvaluator(Product Node)
            : base(Node.Argument)
        {
        }
 
        public override void RestartEvaluator()
        {
            this.product = null;
            this.doubleProduct = 0;
            this.isDouble = true;
        }
 
        public override void AggregateElement(IElement Element)
        {
            if (this.isDouble && Element is DoubleNumber D)
                this.doubleProduct *= D.Value;
            else if (this.product is null)
            {
                this.isDouble = false;
 
                if (this.product is null)
                    this.product = Element;
                else
                    this.product = Multiply.EvaluateMultiplication(new DoubleNumber(this.doubleProduct), Element, this.Node);
            }
            else
                this.product = Multiply.EvaluateMultiplication(this.product, Element, this.Node);
        }
 
        public override IElement GetAggregatedResult()
        {
            if (this.isDouble)
                return new DoubleNumber(this.doubleProduct);
            else 
                return this.product ?? ObjectValue.Null;
        }
    }
}