private async Task ParseValueAsync()

in src/Elastic.Apm/Libraries/Newtonsoft.Json/JsonTextReader.Async.cs [253:382]
118 lines of code
33 McCabe index (conditional complexity)

        private async Task<bool> ParseValueAsync(CancellationToken cancellationToken)
        {
            MiscellaneousUtils.Assert(CharBuffer != null);

            while (true)
            {
                char currentChar = CharBuffer[CharPos];

                switch (currentChar)
                {
                    case '\0':
                        if (_charsUsed == CharPos)
                        {
                            if (await ReadDataAsync(false, cancellationToken).ConfigureAwait(false) == 0)
                            {
                                return false;
                            }
                        }
                        else
                        {
							CharPos++;
                        }

                        break;
                    case '"':
                    case '\'':
                        await ParseStringAsync(currentChar, ReadType.Read, cancellationToken).ConfigureAwait(false);
                        return true;
                    case 't':
                        await ParseTrueAsync(cancellationToken).ConfigureAwait(false);
                        return true;
                    case 'f':
                        await ParseFalseAsync(cancellationToken).ConfigureAwait(false);
                        return true;
                    case 'n':
                        if (await EnsureCharsAsync(1, true, cancellationToken).ConfigureAwait(false))
                        {
                            switch (CharBuffer[CharPos + 1])
                            {
                                case 'u':
                                    await ParseNullAsync(cancellationToken).ConfigureAwait(false);
                                    break;
                                case 'e':
                                    await ParseConstructorAsync(cancellationToken).ConfigureAwait(false);
                                    break;
                                default:
                                    throw CreateUnexpectedCharacterException(CharBuffer[CharPos]);
                            }
                        }
                        else
                        {
							CharPos++;
                            throw CreateUnexpectedEndException();
                        }

                        return true;
                    case 'N':
                        await ParseNumberNaNAsync(ReadType.Read, cancellationToken).ConfigureAwait(false);
                        return true;
                    case 'I':
                        await ParseNumberPositiveInfinityAsync(ReadType.Read, cancellationToken).ConfigureAwait(false);
                        return true;
                    case '-':
                        if (await EnsureCharsAsync(1, true, cancellationToken).ConfigureAwait(false) && CharBuffer[CharPos + 1] == 'I')
                        {
                            await ParseNumberNegativeInfinityAsync(ReadType.Read, cancellationToken).ConfigureAwait(false);
                        }
                        else
                        {
                            await ParseNumberAsync(ReadType.Read, cancellationToken).ConfigureAwait(false);
                        }
                        return true;
                    case '/':
                        await ParseCommentAsync(true, cancellationToken).ConfigureAwait(false);
                        return true;
                    case 'u':
                        await ParseUndefinedAsync(cancellationToken).ConfigureAwait(false);
                        return true;
                    case '{':
						CharPos++;
                        SetToken(JsonToken.StartObject);
                        return true;
                    case '[':
						CharPos++;
                        SetToken(JsonToken.StartArray);
                        return true;
                    case ']':
						CharPos++;
                        SetToken(JsonToken.EndArray);
                        return true;
                    case ',':

                        // don't increment position, the next call to read will handle comma
                        // this is done to handle multiple empty comma values
                        SetToken(JsonToken.Undefined);
                        return true;
                    case ')':
						CharPos++;
                        SetToken(JsonToken.EndConstructor);
                        return true;
                    case StringUtils.CarriageReturn:
                        await ProcessCarriageReturnAsync(false, cancellationToken).ConfigureAwait(false);
                        break;
                    case StringUtils.LineFeed:
                        ProcessLineFeed();
                        break;
                    case ' ':
                    case StringUtils.Tab:

                        // eat
						CharPos++;
                        break;
                    default:
                        if (char.IsWhiteSpace(currentChar))
                        {
                            // eat
							CharPos++;
                            break;
                        }

                        if (char.IsNumber(currentChar) || currentChar == '-' || currentChar == '.')
                        {
                            await ParseNumberAsync(ReadType.Read, cancellationToken).ConfigureAwait(false);
                            return true;
                        }

                        throw CreateUnexpectedCharacterException(currentChar);
                }
            }
        }