Newtonsoft.Json.JsonTextReader.ReadStringValue C# (CSharp) Method

        private object ReadStringValue(ReadType readType)
        {
            EnsureBuffer();

            switch (_currentState)
            {
                case State.Start:
                case State.Property:
                case State.Array:
                case State.ArrayStart:
                case State.Constructor:
                case State.ConstructorStart:
                case State.PostValue:
                    while (true)
                    {
                        char currentChar = _chars[_charPos];

                        switch (currentChar)
                        {
                            case '\0':
                                if (ReadNullChar())
                                {
                                    SetToken(JsonToken.None, null, false);
                                    return null;
                                }
                                break;
                            case '"':
                            case '\'':
                                ParseString(currentChar, readType);
                                switch (readType)
                                {
                                    case ReadType.ReadAsBytes:
                                        return Value;
                                    case ReadType.ReadAsString:
                                        return Value;
                                    case ReadType.ReadAsDateTime:
                                        if (Value is DateTime)
                                        {
                                            return (DateTime)Value;
                                        }
                                        return ReadDateTimeString((string)Value);
#if !NET20
                                    case ReadType.ReadAsDateTimeOffset:
                                        if (Value is DateTimeOffset)
                                        {
                                            return (DateTimeOffset)Value;
                                        }
                                        return ReadDateTimeOffsetString((string)Value);
#endif
                                    default:
                                        throw new ArgumentOutOfRangeException(nameof(readType));
                                }
                            case '-':
                                if (EnsureChars(1, true) && _chars[_charPos + 1] == 'I')
                                {
                                    return ParseNumberNegativeInfinity(readType);
                                }
                                else
                                {
                                    ParseNumber(readType);
                                    return Value;
                                }
                            case '.':
                            case '0':
                            case '1':
                            case '2':
                            case '3':
                            case '4':
                            case '5':
                            case '6':
                            case '7':
                            case '8':
                            case '9':
                                if (readType != ReadType.ReadAsString)
                                {
                                    _charPos++;
                                    throw CreateUnexpectedCharacterException(currentChar);
                                }
                                ParseNumber(ReadType.ReadAsString);
                                return Value;
                            case 't':
                            case 'f':
                                if (readType != ReadType.ReadAsString)
                                {
                                    _charPos++;
                                    throw CreateUnexpectedCharacterException(currentChar);
                                }
                                string expected = currentChar == 't' ? JsonConvert.True : JsonConvert.False;
                                if (!MatchValueWithTrailingSeparator(expected))
                                {
                                    throw CreateUnexpectedCharacterException(_chars[_charPos]);
                                }
                                SetToken(JsonToken.String, expected);
                                return expected;
                            case 'I':
                                return ParseNumberPositiveInfinity(readType);
                            case 'N':
                                return ParseNumberNaN(readType);
                            case 'n':
                                HandleNull();
                                return null;
                            case '/':
                                ParseComment(false);
                                break;
                            case ',':
                                ProcessValueComma();
                                break;
                            case ']':
                                _charPos++;
                                if (_currentState == State.Array || _currentState == State.ArrayStart || _currentState == State.PostValue)
                                {
                                    SetToken(JsonToken.EndArray);
                                    return null;
                                }
                                throw CreateUnexpectedCharacterException(currentChar);
                            case StringUtils.CarriageReturn:
                                ProcessCarriageReturn(false);
                                break;
                            case StringUtils.LineFeed:
                                ProcessLineFeed();
                                break;
                            case ' ':
                            case StringUtils.Tab:
                                // eat
                                _charPos++;
                                break;
                            default:
                                _charPos++;

                                if (!char.IsWhiteSpace(currentChar))
                                {
                                    throw CreateUnexpectedCharacterException(currentChar);
                                }

                                // eat
                                break;
                        }
                    }
                case State.Finished:
                    ReadFinished();
                    return null;
                default:
                    throw JsonReaderException.Create(this, "Unexpected state: {0}.".FormatWith(CultureInfo.InvariantCulture, CurrentState));
            }
        }