bool parseTrunkCharacter()

in lib/src/intl/number_format_parser.dart [293:366]
68 lines of code
19 McCabe index (conditional complexity)

  bool parseTrunkCharacter(trunk) {
    var ch = pattern.current;
    switch (ch) {
      case PATTERN_DIGIT:
        if (zeroDigitCount > 0) {
          digitRightCount++;
        } else {
          digitLeftCount++;
        }
        if (groupingCount >= 0 && decimalPos < 0) {
          groupingCount++;
        }
        break;
      case PATTERN_ZERO_DIGIT:
        if (digitRightCount > 0) {
          throw FormatException('Unexpected "0" in pattern "${pattern.input}');
        }
        zeroDigitCount++;
        if (groupingCount >= 0 && decimalPos < 0) {
          groupingCount++;
        }
        break;
      case PATTERN_GROUPING_SEPARATOR:
        if (groupingCount > 0) {
          groupingSizeSetExplicitly = true;
          result.groupingSize = groupingCount;
        }
        groupingCount = 0;
        break;
      case PATTERN_DECIMAL_SEPARATOR:
        if (decimalPos >= 0) {
          throw FormatException(
              'Multiple decimal separators in pattern "$pattern"');
        }
        decimalPos = digitLeftCount + zeroDigitCount + digitRightCount;
        break;
      case PATTERN_EXPONENT:
        trunk.write(ch);
        if (result.useExponentialNotation) {
          throw FormatException(
              'Multiple exponential symbols in pattern "$pattern"');
        }
        result.useExponentialNotation = true;
        result.minimumExponentDigits = 0;

        // exponent pattern can have a optional '+'.
        pattern.moveNext();
        var nextChar = pattern.current;
        if (nextChar == PATTERN_PLUS) {
          trunk.write(pattern.current);
          pattern.moveNext();
          result.useSignForPositiveExponent = true;
        }

        // Use lookahead to parse out the exponential part
        // of the pattern, then jump into phase 2.
        while (pattern.current == PATTERN_ZERO_DIGIT) {
          trunk.write(pattern.current);
          pattern.moveNext();
          result.minimumExponentDigits++;
        }

        if ((digitLeftCount + zeroDigitCount) < 1 ||
            result.minimumExponentDigits < 1) {
          throw FormatException('Malformed exponential pattern "$pattern"');
        }
        return false;
      default:
        return false;
    }
    trunk.write(ch);
    pattern.moveNext();
    return true;
  }