pkg: analysis aided cleanup

pkg/intl/lib/number_format.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.
 
 part of intl;
 /**
  * Provides the ability to format a number in a locale-specific way. The
  * format is specified as a pattern using a subset of the ICU formatting
  * patterns.
  *
@@ skipping 681 matching lines @@
 /**
  * Return an iterator on the string as a list of substrings.
  */
 Iterator _iterator(String s) => new _StringIterator(s);
 
 // TODO(nweiz): remove this when issue 3780 is fixed.
 /**
  * Provides an Iterable that wraps [_iterator] so it can be used in a `for`
  * loop.
  */
-class _StringIterable extends Iterable<String> {
+class _StringIterable extends IterableBase<String> {
   final Iterator<String> iterator;
 
   _StringIterable(String s)
       : iterator = _iterator(s);
 }
 
 /**
  * Provides an iterator over a string as a list of substrings, and also
  * gives us a lookahead of one via the [peek] method.
  */
 class _StringIterator implements Iterator<String> {
   String input;
   var index = -1;
   inBounds(i) => i >= 0 && i < input.length;
   _StringIterator(this.input);
   String get current => inBounds(index) ? input[index] : null;
 
   bool moveNext() => inBounds(++index);
   String get peek => inBounds(index + 1) ? input[index + 1] : null;
   Iterator<String> get iterator => this;
 }