System.Xml.XmlTextReaderImpl.ParsePI C# (CSharp) Method

        private bool ParsePI(StringBuilder piInDtdStringBuilder)
        {
            if (_parsingMode == ParsingMode.Full)
            {
                _curNode.SetLineInfo(_ps.LineNo, _ps.LinePos);
            }

            Debug.Assert(_stringBuilder.Length == 0);

            // parse target name
            int nameEndPos = ParseName();
            string target = _nameTable.Add(_ps.chars, _ps.charPos, nameEndPos - _ps.charPos);

            if (string.Equals(target, "xml", StringComparison.OrdinalIgnoreCase))
            {
                Throw(target.Equals("xml") ? SR.Xml_XmlDeclNotFirst : SR.Xml_InvalidPIName, target);
            }
            _ps.charPos = nameEndPos;

            if (piInDtdStringBuilder == null)
            {
                if (!_ignorePIs && _parsingMode == ParsingMode.Full)
                {
                    _curNode.SetNamedNode(XmlNodeType.ProcessingInstruction, target);
                }
            }
            else
            {
                piInDtdStringBuilder.Append(target);
            }

            // check mandatory whitespace
            char ch = _ps.chars[_ps.charPos];
            Debug.Assert(_ps.charPos < _ps.charsUsed);
            if (EatWhitespaces(piInDtdStringBuilder) == 0)
            {
                if (_ps.charsUsed - _ps.charPos < 2)
                {
                    ReadData();
                }
                if (ch != '?' || _ps.chars[_ps.charPos + 1] != '>')
                {
                    Throw(SR.Xml_BadNameChar, XmlException.BuildCharExceptionArgs(_ps.chars, _ps.charsUsed, _ps.charPos));
                }
            }

            // scan processing instruction value
            int startPos, endPos;
            if (ParsePIValue(out startPos, out endPos))
            {
                if (piInDtdStringBuilder == null)
                {
                    if (_ignorePIs)
                    {
                        return false;
                    }
                    if (_parsingMode == ParsingMode.Full)
                    {
                        _curNode.SetValue(_ps.chars, startPos, endPos - startPos);
                    }
                }
                else
                {
                    piInDtdStringBuilder.Append(_ps.chars, startPos, endPos - startPos);
                }
            }
            else
            {
                StringBuilder sb;
                if (piInDtdStringBuilder == null)
                {
                    if (_ignorePIs || _parsingMode != ParsingMode.Full)
                    {
                        while (!ParsePIValue(out startPos, out endPos)) ;
                        return false;
                    }
                    sb = _stringBuilder;
                    Debug.Assert(_stringBuilder.Length == 0);
                }
                else
                {
                    sb = piInDtdStringBuilder;
                }

                do
                {
                    sb.Append(_ps.chars, startPos, endPos - startPos);
                } while (!ParsePIValue(out startPos, out endPos));
                sb.Append(_ps.chars, startPos, endPos - startPos);

                if (piInDtdStringBuilder == null)
                {
                    _curNode.SetValue(_stringBuilder.ToString());
                    _stringBuilder.Length = 0;
                }
            }
            return true;
        }