Convert String and List to abstract classes.

lib/core/collection.dart

 // Copyright (c) 2011, 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.
 
 /**
  * The [Collection] interface is the public interface of all
  * collections.
  */
 abstract class Collection<E> extends Iterable<E> {
   /**
@@ skipping 14 matching lines @@
   /**
    * Reduce a collection to a single value by iteratively combining each element
    * of the collection with an existing value using the provided function.
    * Use [initialValue] as the initial value, and the function [combine] to
    * create a new value from the previous one and an element.
    *
    * Example of calculating the sum of a collection:
    *
    *   collection.reduce(0, (prev, element) => prev + element);
    */
-  Dynamic reduce(Dynamic initialValue,
-                 Dynamic combine(Dynamic previousValue, E element));
+  Dynamic reduce(var initialValue,

[srdjan, 2012/09/28 17:52:22]

Why not remove Dynamic everywhere?

[Lasse Reichstein Nielsen, 2012/09/30 20:46:43]

"var" is not a valid return type, and I don't like not writing a return type
(looks like an omission).

[srdjan, 2012/10/02 17:21:14]

This is not the the style that has been used by most people in Dart team
(checked with Ivan and Bob). It is important that we have a unified style in the
libraries.I.e., rather than "Dynamic foo(var a, var b)", we should write "foo(a,
b)"

+                 Dynamic combine(var previousValue, E element));
 
   /**
    * Returns a new collection with the elements of this collection
    * that satisfy the predicate [f].
    *
    * An element satisfies the predicate [f] if [:f(element):]
    * returns true.
    */
   Collection<E> filter(bool f(E element));
 
@@ skipping 12 matching lines @@
   /**
    * Returns true if there is no element in this collection.
    */
   bool isEmpty();
 
   /**
    * Returns the number of elements in this collection.
    */
   int get length;
 }