Change List constructors.

sdk/lib/core/list.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.
 
 /**
  * A [List] is an indexable collection with a length. It can be of
  * fixed size or extendable.
  */
 interface List<E> extends Collection<E>, Sequence<E>
                   default _ListImpl<E> {
   /**
-   * Creates a list of the given [length].
-   *
-   * If no [length] argument is supplied an extendable list of
-   * length 0 is created.
-   *
-   * If a [length] argument is supplied, a fixed size list of that
-   * length is created.
+   * Creates an extendable list of the given [length].

[sra1, 2012/11/07 21:36:34]

'extendable' is not quite right since it can be shrunk.

[floitsch, 2012/11/12 13:21:50]

reworded.

    */
-  List([int length]);
+  List([int length = 0]);
 
   /**
-   * Creates a list with the elements of [other]. The order in
+   * Creates a fixed-sized list of the given [length] where each entry is
+   * filled with [fill].
+   */
+  List.fixedLength(int length, {E fill: null});
+
+  /**
+   * Creates an extendable list of the given [length] where each entry is
+   * filled with [fill].
+   */
+  List.filled(int length, E fill);

[sra1, 2012/11/07 21:36:34]

It is a pity that 'fill' is a named parameter in one constructor and part of the
name in another.

As I programmer I would like to be able to write:

new List();
new List(10);
new List(10, fill: 0);

new List.fixedLength(10);
new List.fixedLength(10, fill: 0);

I'd be happy to remove new List() and recommend writing the more concise [] or
<T>[].

[floitsch, 2012/11/12 13:21:50]

Completely agree. There is bug open, but currently we can't do otherwise.

+
+  /**
+   * Creates an extandable list with the elements of [other]. The order in

[sra1, 2012/11/07 21:36:34]

extEndable, if you keep the name.

[floitsch, 2012/11/12 13:21:50]

Reworded.

    * the list will be the order provided by the iterator of [other].
    */
   List.from(Iterable<E> other);
 
   /**
    * Returns the element at the given [index] in the list or throws
    * an [RangeError] if [index] is out of bounds.
    */
   E operator [](int index);
 
@@ skipping 131 matching lines @@
    * [:start + length - 1:]. The entries are filled with [initialValue].
    * Throws an [UnsupportedError] if the list is
    * not extendable.
    * If [length] is 0, this method does not do anything.
    * If [start] is the length of the list, this method inserts the
    * range at the end of the list.
    * Throws an [ArgumentError] if [length] is negative.
    * Throws an [RangeError] if [start] is negative or if
    * [start] is greater than the length of the list.
    */
   void insertRange(int start, int length, [E initialValue]);

[sra1, 2012/11/07 21:36:34]

Should initialValue be renamed to fill?

[floitsch, 2012/11/12 13:21:50]

Done.

 }
 
 class _ListImpl<E> {
   /**
    * Factory implementation of List().
    *
-   * Creates a list of the given [length].
+   * Creates an extendable list of the given [length].
    */
-  external factory List([int length]);
+  external factory List([int length = 0]);
+
+  /**
+   * Creates a fixed-sized list of the given [length] where each entry is
+   * filled with [fill].
+   */
+  external factory List.fixedLength(int length, {E fill: null});
+
+  /**
+   * Creates an extendable list of the given [length] where each entry is
+   * filled with [fill].
+   */
+  external factory List.filled(int length, E fill);
 
   /**
    * Factory implementation of List.from().
    *
    * Creates a list with the elements of [other]. The order in
    * the list will be the order provided by the iterator of [other].
    */
   external factory List.from(Iterable<E> other);
 }