System.Security.Util.Parser.DetermineFormat C# (CSharp) Method

        private int DetermineFormat( TokenizerStream stream )
        {
            if (stream.GetNextToken() == Tokenizer.bra)
            {
                if (stream.GetNextToken() == Tokenizer.quest)
                {
                    _t.GetTokens( stream, -1, true );
                    stream.GoToPosition( 2 );

                    bool sawEquals = false;
                    bool sawEncoding = false;

                    short i;

                    for (i = stream.GetNextToken(); i != -1 && i != Tokenizer.ket; i = stream.GetNextToken())
                    {
                        switch (i)
                        {
                        case Tokenizer.cstr:
                            if (sawEquals && sawEncoding)
                            {
                                _t.ChangeFormat( System.Text.Encoding.GetEncoding( stream.GetNextString() ) );
                                return 0;
                            }
                            else if (!sawEquals)
                            {
                                if (String.Compare( stream.GetNextString(), "encoding", StringComparison.Ordinal) == 0)
                                    sawEncoding = true;
                            }
                            else
                            {
                                sawEquals = false;
                                sawEncoding = false;
                                stream.ThrowAwayNextString();
                            }
                            break;

                        case Tokenizer.equals:
                            sawEquals = true;
                            break;

                        default:
                            throw new XmlSyntaxException (_t.LineNo, Environment.GetResourceString( "XMLSyntax_UnexpectedEndOfFile" ));
                        }
                    }

                    return 0;
                }
            }

            return 2;
        }