anchor.diff:        });
       }
       return true;
  +  }
  +
  +  if (trimmedText.startsWith('//')) {
  +    if(!atEol || trimmedText.endsWith(',')) {
  +      editor.atomic(() {
  +        editor.insertNewline();
  +        editor.insertText('// ');
  +      });
  +
  +      return true;
  +    }
  +
  +    return false;
     }
   
     if (trimmedText.startsWith('/*')) {
  
positive.code: import '../atom.dart';
  
  final Logger _logger = new Logger('editing');
  
  // TODO: If we're in a line comment, and the line is longer than the max line
  // length, extend the comment.
  // var prefLineLength = atom.config.get('editor.preferredLineLength',
  //   scope: editor.getRootScopeDescriptor());
  
  // TODO: Tests for this.
  
  
negative.code:     String temp = trimmedText.substring(3).trimLeft();
      leading = trimmedText.substring(3, trimmedText.length - temp.length);
      inComment = (line.length - trimmedText.length + 2) <= col;
    } else if(trimmedText.startsWith('//')) {
      inComment = (line.length - trimmedText.length + 1) <= col;
    } else if (trimmedText.startsWith('*')) {
      String temp = trimmedText.substring(1).trimLeft();
      leading = trimmedText.substring(1, trimmedText.length - temp.length);
  