Added preview comments to libaries in library_list

pkg/docgen/lib/docgen.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * **docgen** is a tool for creating machine readable representations of Dart
  * code metadata, including: classes, members, comments and annotations.
  *
  * docgen is run on a `.dart` file or a directory containing `.dart` files.
  *
@@ skipping 206 matching lines @@
   entityMap.values.where((e) => e is Class).forEach((c) => c.makeValid());
   // Everything is a subclass of Object, therefore empty the list to avoid a
   // giant list of subclasses to be printed out.
   if (parseSdk) entityMap['dart.core.Object'].subclasses.clear();
 
   var filteredEntities = entityMap.values.where(_isVisible);
   // Output libraries and classes to file after all information is generated.
   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) => 
       '${e.qualifiedName} ${e.typeName}').join('\n'),
       'index.txt', append: append);
 }
 
 Library generateLibrary(dart2js.Dart2JsLibraryMirror library) {
   _currentLibrary = library;
   var result = new Library(library.qualifiedName, _commentToHtml(library),
@@ skipping 272 matching lines @@
 
   /// Qualified Name of the owner of this Indexable Item.
   /// For Library, owner will be "";
   String owner;
 
   Indexable(this.name, this.comment, this.qualifiedName, this.isPrivate,
       this.owner);
   
   /// 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;
+  }
 }
 
 /**
  * A class containing contents of a Dart library.
  */
 class Library extends Indexable {
 
   /// Top-level variables in the library.
   Map<String, Variable> variables;
 
@@ skipping 209 matching lines @@
       throw new ArgumentError('${mirror.simpleName} - no class type match. ');
     }
   }
 
   /**
    * Checks if the given name is a key for any of the Class Maps.
    */
   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(),
+      .map((e) => e.previewMap).toList(),
     'typedef': recurseMap(typedefs),
     'error': errors.values.where(_isVisible)
-      .map((e) => classMap(e)).toList()
+      .map((e) => e.previewMap).toList()
   };
 }
 
 class Typedef extends Indexable {
   String returnType;
 
   Map<String, Parameter> parameters;
 
   /// Generic information about the typedef.
   Map<String, Generic> generics;
@@ skipping 278 matching lines @@
   String qualifiedName;
   List<String> parameters;
 
   Annotation(this.qualifiedName, this.parameters);
 
   Map toMap() => {
     'name': qualifiedName,
     'parameters': parameters
   };
 }