Adding isNotEmpty property to collection and string.

runtime/lib/typed_data.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.
 
 // patch classes for Int8List ..... Float64List and ByteData implementations.
 
 patch class Int8List {
   /* patch */ factory Int8List(int length) {
     return new _Int8Array(length);
   }
@@ skipping 340 matching lines @@
   }
 
   int elementAt(int index) {
     return this[index];
   }
 
   bool get isEmpty {
     return this.length == 0;
   }
 
+  bool get isNotEmpty => !isEmpty;
 
   // Method(s) implementing the List interface.
 
   set length(newLength) {
     throw new UnsupportedError(
         "Cannot resize a non-extendable array");
   }
 
   void add(value) {
     throw new UnsupportedError(
@@ skipping 2734 matching lines @@
     return value;
   }
   return object;
 }
 
 
 void _throwRangeError(int index, int length) {
   String message = "$index must be in the range [0..$length)";
   throw new RangeError(message);
 }