Year.cs

using System.Threading.Tasks;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Functions.DateAndTime
{
    public class Year : FunctionOneScalarVariable
    {
        public Year(ScriptNode Argument, int Start, int Year, Expression Expression)
            : base(Argument, Start, Year, Expression)
        {
        }
 
        public override string FunctionName => nameof(Year);
 
        public override string[] Aliases => new string[] { "Years" };
 
        public override IElement EvaluateScalar(IElement Argument, Variables Variables)
        {
            if (Argument.AssociatedObjectValue is System.DateTime TP)
                return new DoubleNumber(TP.Year);
            else if (Argument.AssociatedObjectValue is System.DateTimeOffset TPO)
                return new DoubleNumber(TPO.Year);
            else if (Argument.AssociatedObjectValue is IYears D)
                return new DoubleNumber(D.Years);
            else
                throw new ScriptRuntimeException("Unable to extract number of years.", this);
        }
 
        public override Task<IElement> EvaluateScalarAsync(IElement Argument, Variables Variables)
        {
            return Task.FromResult(this.EvaluateScalar(Argument, Variables));
        }
    }
}