YamlDotNet.Core.Scanner.ScanUriEscapes C# (CSharp) Method

        private string ScanUriEscapes(Mark start)
        {
            // Decode the required number of characters.

            byte[] charBytes = null;
            int nextInsertionIndex = 0;
            int width = 0;
            do
            {
                // Check for a URI-escaped octet.

                if (!(analyzer.Check('%') && analyzer.IsHex(1) && analyzer.IsHex(2)))
                {
                    throw new SyntaxErrorException(start, cursor.Mark(), "While parsing a tag, did not find URI escaped octet.");
                }

                // Get the octet.

                int octet = (analyzer.AsHex(1) << 4) + analyzer.AsHex(2);

                // If it is the leading octet, determine the length of the UTF-8 sequence.

                if (width == 0)
                {
                    width = (octet & 0x80) == 0x00 ? 1 :
                            (octet & 0xE0) == 0xC0 ? 2 :
                            (octet & 0xF0) == 0xE0 ? 3 :
                            (octet & 0xF8) == 0xF0 ? 4 : 0;

                    if (width == 0)
                    {
                        throw new SyntaxErrorException(start, cursor.Mark(), "While parsing a tag, find an incorrect leading UTF-8 octet.");
                    }

                    charBytes = new byte[width];
                }
                else
                {
                    // Check if the trailing octet is correct.

                    if ((octet & 0xC0) != 0x80)
                    {
                        throw new SyntaxErrorException(start, cursor.Mark(), "While parsing a tag, find an incorrect trailing UTF-8 octet.");
                    }
                }

                // Copy the octet and move the pointers.

                charBytes[nextInsertionIndex++] = (byte)octet;

                Skip();
                Skip();
                Skip();
            }
            while (--width > 0);

            var result = Encoding.UTF8.GetString(charBytes, 0, nextInsertionIndex);

            if (result.Length == 0 || result.Length > 2)
            {
                throw new SyntaxErrorException(start, cursor.Mark(), "While parsing a tag, find an incorrect UTF-8 sequence.");
            }

            return result;
        }