private object Add(object left, object right)
        {
            if (left.GetType() == typeof(string))
            {
                return((string)left + right);
            }
            else if (right.GetType() == typeof(string))
            {
                return(left + (string)right);
            }
            else if (left.GetType() == typeof(char))
            {
                return(Types.ConvertValue <string>((char)left) + right);
            }
            else if (right.GetType() == typeof(char))
            {
                return(left + Types.ConvertValue <string>((char)right));
            }
            else if (Types.IsPrimitiveType(left.GetType()) && Types.IsPrimitiveType(right.GetType()))
            {
                int index = Types.ResolvePrimitiveTypeIndex(left.GetType(), right.GetType());
                return(MathSnippets.Add(
                           Types.CoerceValue(left, index),
                           Types.CoerceValue(right, index),
                           index));
            }


            return(null);
        }
        private object Divide(object left, object right)
        {
            int index = Types.ResolvePrimitiveTypeIndex(left.GetType(), right.GetType());

            return(MathSnippets.Divide(
                       Types.CoerceValue(left, index),
                       Types.CoerceValue(right, index),
                       index));
        }
        private object NotEqual(object left, object right)
        {
            if (left == null && right != null && right.GetType() == typeof(string))
            {
                return(true);
            }
            else if (left != null && left.GetType() == typeof(string) && right == null)
            {
                return(false);
            }
            else if (left.GetType() == typeof(string) && right.GetType() == typeof(string))
            {
                return(((string)left).CompareTo((string)right) != 0);
            }
            else
            {
                int index = Types.ResolvePrimitiveTypeIndex(left.GetType(), right.GetType());

                return(MathSnippets.NotEqual(
                           Types.CoerceValue(left, index),
                           Types.CoerceValue(right, index),
                           index));
            }
        }