pkg/docgen: support better const rendering of String, List, and empty Map

pkg/docgen/lib/src/models.dart

 // Copyright (c) 2014, 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.
 
 library docgen.models;
 
 import 'dart:io';
 
 import 'package:markdown/markdown.dart' as markdown;
 
@@ skipping 456 matching lines @@
     if (domAnnotation == null) return '';
     var domName = domAnnotation.parameters.single;
 
     return mdnComment(rootDirectory, logger, domName);
   }
 
   String get packagePrefix => owner.packagePrefix;
 }
 
 /// A class containing contents of a Dart class.
-class Class
-    extends OwnedIndexable<dart2js_mirrors.Dart2JsInterfaceTypeMirror>
+class Class extends OwnedIndexable<dart2js_mirrors.Dart2JsInterfaceTypeMirror>
     implements Comparable<Class> {
 
   /// List of the names of interfaces that this class implements.
   List<Class> interfaces = [];
 
   /// Names of classes that extends or implements this class.
   Set<Class> subclasses = new Set<Class>();
 
   /// Top-level variables in the class.
   Map<String, Variable> variables;
@@ skipping 486 matching lines @@
   final String defaultValue;
   /// List of the meta annotations on the parameter.
   final List<Annotation> annotations;
 
   Parameter(ParameterMirror mirror, Library owningLibrary)
       : this.mirror = mirror,
         name = dart2js_util.nameOf(mirror),
         isOptional = mirror.isOptional,
         isNamed = mirror.isNamed,
         hasDefaultValue = mirror.hasDefaultValue,
-        defaultValue = '${mirror.defaultValue}',
+        defaultValue = getDefaultValue(mirror),
         type = new Type(mirror.type, owningLibrary),
         annotations = createAnnotations(mirror, owningLibrary);
 
   /// Generates a map describing the [Parameter] object.
   Map toMap() => {
     'name': name,
     'optional': isOptional,
     'named': isNamed,
     'default': hasDefaultValue,
     'type': new List.filled(1, type.toMap()),
@@ skipping 68 matching lines @@
         .map((e) => originalMirror.getField(e.simpleName).reflectee)
         .where((e) => e != null)
         .toList();
   }
 
   Map toMap() => {
     'name': getDocgenObject(mirror, owningLibrary).docName,
     'parameters': parameters
   };
 }