public IValue Add(IValueWithMathOperands other, IValueFactory fac)
{
return(other.Type switch
{
EilangType.String => fac.String(Item + other.As <StringValue>().Item),
EilangType.Integer => fac.Double(Item + other.Get <int>()),
EilangType.Long => fac.Double(Item + other.Get <long>()),
EilangType.Double => fac.Double(Item + other.Get <double>()),
EilangType.Byte => fac.Double(Item + other.Get <byte>()),
_ => throw ThrowHelper.TypeMismatch(Type, "+", other.Type)
});
