bool _generateSpans()

in tool/codeviewer_cli/prehighlighter.dart [120:300]
142 lines of code
26 McCabe index (conditional complexity)

  bool _generateSpans() {
    var lastLoopPosition = _scanner.position;

    while (!_scanner.isDone) {
      // Skip White space
      _scanner.scan(RegExp(r'\s+'));

      // Block comments
      if (_scanner.scan(RegExp(r'/\*(.|\n)*\*/'))) {
        _spans.add(_HighlightSpan(
          _HighlightType.comment,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // Line comments
      if (_scanner.scan('//')) {
        final startComment = _scanner.lastMatch.start;

        var eof = false;
        int endComment;
        if (_scanner.scan(RegExp(r'.*\n'))) {
          endComment = _scanner.lastMatch.end - 1;
        } else {
          eof = true;
          endComment = _src.length;
        }

        _spans.add(_HighlightSpan(
          _HighlightType.comment,
          startComment,
          endComment,
        ));

        if (eof) {
          break;
        }

        continue;
      }

      // Raw r"String"
      if (_scanner.scan(RegExp(r'r".*"'))) {
        _spans.add(_HighlightSpan(
          _HighlightType.string,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // Raw r'String'
      if (_scanner.scan(RegExp(r"r'.*'"))) {
        _spans.add(_HighlightSpan(
          _HighlightType.string,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // Multiline """String"""
      if (_scanner.scan(RegExp(r'"""(?:[^"\\]|\\(.|\n))*"""'))) {
        _spans.add(_HighlightSpan(
          _HighlightType.string,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // Multiline '''String'''
      if (_scanner.scan(RegExp(r"'''(?:[^'\\]|\\(.|\n))*'''"))) {
        _spans.add(_HighlightSpan(
          _HighlightType.string,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // "String"
      if (_scanner.scan(RegExp(r'"(?:[^"\\]|\\.)*"'))) {
        _spans.add(_HighlightSpan(
          _HighlightType.string,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // 'String'
      if (_scanner.scan(RegExp(r"'(?:[^'\\]|\\.)*'"))) {
        _spans.add(_HighlightSpan(
          _HighlightType.string,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // Double
      if (_scanner.scan(RegExp(r'\d+\.\d+'))) {
        _spans.add(_HighlightSpan(
          _HighlightType.number,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // Integer
      if (_scanner.scan(RegExp(r'\d+'))) {
        _spans.add(_HighlightSpan(_HighlightType.number,
            _scanner.lastMatch.start, _scanner.lastMatch.end));
        continue;
      }

      // Punctuation
      if (_scanner.scan(RegExp(r'[\[\]{}().!=<>&\|\?\+\-\*/%\^~;:,]'))) {
        _spans.add(_HighlightSpan(
          _HighlightType.punctuation,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // Meta data
      if (_scanner.scan(RegExp(r'@\w+'))) {
        _spans.add(_HighlightSpan(
          _HighlightType.keyword,
          _scanner.lastMatch.start,
          _scanner.lastMatch.end,
        ));
        continue;
      }

      // Words
      if (_scanner.scan(RegExp(r'\w+'))) {
        _HighlightType type;

        var word = _scanner.lastMatch[0];
        if (word.startsWith('_')) {
          word = word.substring(1);
        }

        if (_keywords.contains(word)) {
          type = _HighlightType.keyword;
        } else if (_builtInTypes.contains(word)) {
          type = _HighlightType.keyword;
        } else if (_firstLetterIsUpperCase(word)) {
          type = _HighlightType.klass;
        } else if (word.length >= 2 &&
            word.startsWith('k') &&
            _firstLetterIsUpperCase(word.substring(1))) {
          type = _HighlightType.constant;
        }

        if (type != null) {
          _spans.add(_HighlightSpan(
            type,
            _scanner.lastMatch.start,
            _scanner.lastMatch.end,
          ));
        }
      }

      // Check if this loop did anything
      if (lastLoopPosition == _scanner.position) {
        // Failed to parse this file, abort gracefully
        return false;
      }
      lastLoopPosition = _scanner.position;
    }

    _simplify();
    return true;
  }