Fan.Sys.Uri.Decoder.substring C# (CSharp) Method

            private string substring(int start, int end, int section)
            {
                if (!decoding) return str.Substring(start, end-start);

                StringBuilder buf = new StringBuilder(end-start);
                dpos = start;
                while (dpos < end)
                {
                   int ch = nextChar(section);
                   if (nextCharWasEscaped && ch < delimEscMap.Length && (delimEscMap[ch] & section) != 0)
                 buf.Append('\\');
                   buf.Append((char)ch);
                }
                return buf.ToString();
            }