LambdaOrder.cs

using System;
using System.Collections.Generic;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Model;
 
namespace Waher.Script.Order
{
    public class LambdaOrder : IComparer<IElement>
    {
        private readonly ILambdaExpression lambda;
        private readonly IElement[] arguments;
        private readonly Variables variables;
 
        public LambdaOrder(ILambdaExpression Lambda, Variables Variables)
        {
            this.lambda = Lambda;
            this.arguments = new IElement[2];
            this.variables = Variables;
        }
 
        public int Compare(IElement x, IElement y)
        {
            this.arguments[0] = x;
            this.arguments[1] = y;
 
            IElement Result = this.lambda.Evaluate(this.arguments, this.variables);
 
            return Math.Sign(Expression.ToDouble(Result));
        }
    }
}