Refactor Future constructors.

utils/pub/utils.dart

 // Copyright (c) 2012, 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.
 
 /// Generic utility functions. Stuff that should possibly be in core.
 library utils;
 
 import 'dart:async';
 import 'dart:crypto';
 import 'dart:isolate';
@@ skipping 231 matching lines @@
         if (!buffer.isEmpty) sink.add(buffer.toString());
         sink.close();
       }));
 }
 
 /// Like [Iterable.where], but allows [test] to return [Future]s and uses the
 /// results of those [Future]s as the test.
 Future<Iterable> futureWhere(Iterable iter, test(value)) {
   return Future.wait(iter.map((e) {
     var result = test(e);
-    if (result is! Future) result = new Future.immediate(result);
+    if (result is! Future) result = new Future.value(result);
     return result.then((result) => new Pair(e, result));
   }))
       .then((pairs) => pairs.where((pair) => pair.last))
       .then((pairs) => pairs.map((pair) => pair.first));
 }
 
 // TODO(nweiz): unify the following functions with the utility functions in
 // pkg/http.
 
 /// Like [String.split], but only splits on the first occurrence of the pattern.
@@ skipping 73 matching lines @@
 
 /// Takes a simple data structure (composed of [Map]s, [Iterable]s, scalar
 /// objects, and [Future]s) and recursively resolves all the [Future]s contained
 /// within. Completes with the fully resolved structure.
 Future awaitObject(object) {
   // Unroll nested futures.
   if (object is Future) return object.then(awaitObject);
   if (object is Iterable) {
     return Future.wait(object.map(awaitObject).toList());
   }
-  if (object is! Map) return new Future.immediate(object);
+  if (object is! Map) return new Future.value(object);
 
   var pairs = <Future<Pair>>[];
   object.forEach((key, value) {
     pairs.add(awaitObject(value)
         .then((resolved) => new Pair(key, resolved)));
   });
   return Future.wait(pairs).then((resolvedPairs) {
     var map = {};
     for (var pair in resolvedPairs) {
       map[pair.first] = pair.last;
     }
     return map;
   });
 }