Pchp.Library.Arrays.RangeOfChars C# (CSharp) Method

        private static PhpArray RangeOfChars(char low, char high, int step)
        {
            if (step == 0)
            {
                //PhpException.InvalidArgument("step", LibResources.GetString("arg:zero"));
                //step = 1;
                throw new ArgumentException();
            }

            if (step < 0) step = -step;

            PhpArray result = new PhpArray(Math.Abs(high - low) / step + 1, 0);
            if (high >= low)
            {
                for (int i = 0; low <= high; i++, low = unchecked((char)(low + step))) result.Add(i, low.ToString());
            }
            else
            {
                for (int i = 0; low >= high; i++, low = unchecked((char)(low - step))) result.Add(i, low.ToString());
            }

            return result;
        }