Round.cs

using System;
using System.Collections.Generic;
using System.Numerics;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Functions.Scalar
{
    public class Round : FunctionOneScalarVariable
    {
        public Round(ScriptNode Argument, int Start, int Length, Expression Expression)
            : base(Argument, Start, Length, Expression)
        {
        }
 
        public override string FunctionName => nameof(Round);
 
        public override IElement EvaluateScalar(double Argument, Variables Variables)
        {
            return new DoubleNumber(Math.Round(Argument));
        }
 
        public override IElement EvaluateScalar(Complex Argument, Variables Variables)
        {
            return new ComplexNumber(new Complex(Math.Round(Argument.Real), Math.Round(Argument.Imaginary)));
        }
 
        public override PatternMatchResult PatternMatch(IElement CheckAgainst, Dictionary<string, IElement> AlreadyFound)
        {
            object Obj = CheckAgainst.AssociatedObjectValue;
 
            if (Obj is double d)
            {
                if (Math.Truncate(d) != d)
                    return PatternMatchResult.NoMatch;
            }
            else if (Obj is Complex z)
            {
                d = z.Real;
                if (Math.Truncate(d) != d)
                    return PatternMatchResult.NoMatch;
 
                d = z.Imaginary;
                if (Math.Truncate(d) != d)
                    return PatternMatchResult.NoMatch;
            }
            else
                return PatternMatchResult.NoMatch;
 
            return this.Argument.PatternMatch(CheckAgainst, AlreadyFound);
        }
    }
}