anchor.diff:    filteredEntities.where((e) => e is Class || e is Library).forEach((output) {
       _writeIndexableToFile(output, outputToYaml);
     });
  -  // Outputs a text file with a list of libraries available after creating all
  -  // the libraries. This will help the viewer know what libraries are available
  -  // to read in.
  -  _writeToFile(filteredEntities.where((e) => e is Library)
  -      .map((e) => e.qualifiedName).join('\n'), 'library_list.txt',
  -      append: append);
  +  // Outputs a yaml file with all libraries and their preview comments after 
  +  // creating all libraries. This will help the viewer know what libraries are 
  +  // available to read in.
  +  var libraryMap = {'libraries' : filteredEntities.where((e) => 
  +      e is Library).map((e) => e.previewMap).toList()};
  +  _writeToFile(getYamlString(libraryMap), 'library_list.yaml', append: append);
     // Outputs all the qualified names documented with their type.
     // This will help generate search results.
     _writeToFile(filteredEntities.map((e) => 
  
positive.code:   bool containsKey(String name) {
      return classes.containsKey(name) || errors.containsKey(name);
    }
  
    /**
     * Creates a [Map] with [Class] names and a preview comment.
     */
    Map classMap(Class clazz) {
      var finalMap = { 'name' : clazz.qualifiedName };
      if (clazz.comment != '') {
        var index = clazz.comment.indexOf('</p>');
        finalMap['preview'] = '${clazz.comment.substring(0, index)}</p>';
      }
      return finalMap;
    }
    
    Map toMap() => {
      'class': classes.values.where(_isVisible)
        .map((e) => classMap(e)).toList(),
      'typedef': recurseMap(typedefs),
      'error': errors.values.where(_isVisible)
        .map((e) => classMap(e)).toList()
    };
  }
  
  
negative.code:   
    /// The type of this member to be used in index.txt.
    String get typeName => '';
    
    /**
     * Creates a [Map] with this [Indexable]'s name and a preview comment.
     */
    Map get previewMap {
      var finalMap = { 'name' : qualifiedName };
      if (comment != '') {
        var index = comment.indexOf('</p>');
        finalMap['preview'] = '${comment.substring(0, index)}</p>';
      }
      return finalMap;
    }
  }
  
  /**
  