XorEvaluator.cs

using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Functions.Vectors
{
    public class XorEvaluator : UnaryIterativeEvaluator
    {
        private ulong integerResult = 0;
        private bool integerSigned = false;
        private bool booleanResult = false;
        private bool isBoolean = false;
        private bool isInteger = false;
        private bool first = true;
 
        public XorEvaluator(Xor Node)
            : base(Node.Argument)
        {
        }
 
        public override void RestartEvaluator()
        {
            this.integerResult = 0;
            this.booleanResult = false;
            this.isInteger = false;
            this.isBoolean = false;
            this.first = true;
        }
 
        public override void AggregateElement(IElement Element)
        {
            if (this.first)
            {
                this.first = false;
 
                if (Element is BooleanValue B)
                {
                    this.isBoolean = true;
                    this.booleanResult = B.Value;
                }
                else if (Element is DoubleNumber D)
                {
                    this.isInteger = true;
                    this.integerResult = Operators.Binary.And.ToUInt64(D.Value,
                        out this.integerSigned, this.Node);
                }
                else
                    throw new ScriptRuntimeException("Operands must be integer or Boolean values.", this.Node);
            }
            else if (this.isBoolean)
            {
                if (Element is BooleanValue B)
                    this.booleanResult ^= B.Value;
                else
                    throw new ScriptRuntimeException("Operands do not match.", this.Node);
            }
            else if (this.isInteger)
            {
                if (Element is DoubleNumber D)
                {
                    ulong Value = Operators.Binary.And.ToUInt64(D.Value, out bool Signed, this.Node);
 
                    this.integerResult ^= Value;
                    this.integerSigned ^= Signed;
                }
                else
                    throw new ScriptRuntimeException("Operands do not match.", this.Node);
            }
            else
                throw new ScriptRuntimeException("Operands must be integer or Boolean values.", this.Node);
        }
 
        public override IElement GetAggregatedResult()
        {
            if (this.first)
                return ObjectValue.Null;
            else if (this.isBoolean)
                return this.booleanResult ? BooleanValue.True : BooleanValue.False;
            else if (this.isInteger)
            {
                if (this.integerSigned)
                    return new DoubleNumber((long)this.integerResult);
                else
                    return new DoubleNumber(this.integerResult);
            }
            else
                throw new ScriptRuntimeException("Operands must be integer or Boolean values.", this.Node);
        }
    }
}