System.Text.RegularExpressions.RegexParser.ScanOptions C# (CSharp) Method

        internal void ScanOptions()
        {
            char ch;
            bool off;
            RegexOptions option;

            for (off = false; CharsRight() > 0; MoveRight())
            {
                ch = RightChar();

                if (ch == '-')
                {
                    off = true;
                }
                else if (ch == '+')
                {
                    off = false;
                }
                else
                {
                    option = OptionFromCode(ch);
                    if (option == 0 || IsOnlyTopOption(option))
                        return;

                    if (off)
                        _options &= ~option;
                    else
                        _options |= option;
                }
            }
        }